CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>Sinoatrial node - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available";var cookie=document.cookie.match(/(?:^|; )enwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy", "wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"b583855e-3d61-4a43-b481-51b19d502897","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"Sinoatrial_node","wgTitle":"Sinoatrial node","wgCurRevisionId":1251688092,"wgRevisionId":1251688092,"wgArticleId":598570,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["CS1 maint: location missing publisher","Articles with short description","Short description matches Wikidata","Use dmy dates from April 2017","Cardiac anatomy"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Sinoatrial_node","wgRelevantArticleId":598570,"wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[],"wgNoticeProject":"wikipedia", "wgCiteReferencePreviewsActive":false,"wgFlaggedRevsParams":{"tags":{"status":{"levels":1}}},"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":false,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":20000,"wgRelatedArticlesCompat":[],"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q286020","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform","platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false,"wgGEStructuredTaskRejectionReasonTextInputEnabled":false,"wgGELevelingUpEnabledForUser":false};RLSTATE={ "ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","mediawiki.page.gallery.styles":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","jquery.makeCollapsible.styles":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["ext.cite.ux-enhancements","mediawiki.page.media","site","mediawiki.page.ready","jquery.makeCollapsible","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.ReferenceTooltips","ext.gadget.switcher","ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap","ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader", "ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming","ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.growthExperiments.SuggestedEditSession","wikibase.sidebar.tracking"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.cite.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cmediawiki.page.gallery.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.5"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/e/e6/Reizleitungssystem_1.png"> <meta property="og:image:width" content="1200"> <meta property="og:image:height" content="1810"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Reizleitungssystem_1.png/800px-Reizleitungssystem_1.png"> <meta property="og:image:width" content="800"> <meta property="og:image:height" content="1207"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Reizleitungssystem_1.png/640px-Reizleitungssystem_1.png"> <meta property="og:image:width" content="640"> <meta property="og:image:height" content="965"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="Sinoatrial node - Wikipedia"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//en.m.wikipedia.org/wiki/Sinoatrial_node"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=Sinoatrial_node&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (en)"> <link rel="EditURI" type="application/rsd+xml" href="//en.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://en.wikipedia.org/wiki/Sinoatrial_node"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en"> <link rel="alternate" type="application/atom+xml" title="Wikipedia Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="//login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Sinoatrial_node rootpage-Sinoatrial_node skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Jump to content</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Main menu" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Main menu</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Main menu</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">hide</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z"><span>Main page</span></a></li><li id="n-contents" class="mw-list-item"><a href="/wiki/Wikipedia:Contents" title="Guides to browsing Wikipedia"><span>Contents</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:Current_events" title="Articles related to current events"><span>Current events</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:Random" title="Visit a randomly selected article [x]" accesskey="x"><span>Random article</span></a></li><li id="n-aboutsite" class="mw-list-item"><a href="/wiki/Wikipedia:About" title="Learn about Wikipedia and how it works"><span>About Wikipedia</span></a></li><li id="n-contactpage" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us" title="How to contact Wikipedia"><span>Contact us</span></a></li> </ul> </div> </div> <div id="p-interaction" class="vector-menu mw-portlet mw-portlet-interaction" > <div class="vector-menu-heading"> Contribute </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:Contents" title="Guidance on how to use and edit Wikipedia"><span>Help</span></a></li><li id="n-introduction" class="mw-list-item"><a href="/wiki/Help:Introduction" title="Learn how to edit Wikipedia"><span>Learn to edit</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:Community_portal" title="The hub for editors"><span>Community portal</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:RecentChanges" title="A list of recent changes to Wikipedia [r]" accesskey="r"><span>Recent changes</span></a></li><li id="n-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_upload_wizard" title="Add images or other media for use on Wikipedia"><span>Upload file</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Main_Page" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" style="width: 7.5em; height: 1.125em;"> <img class="mw-logo-tagline" alt="The Free Encyclopedia" src="/static/images/mobile/copyright/wikipedia-tagline-en.svg" width="117" height="13" style="width: 7.3125em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:Search" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Search Wikipedia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia" aria-label="Search Wikipedia" autocapitalize="sentences" title="Search Wikipedia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Personal tools"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Change the appearance of the page's font size, width, and color" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Appearance" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Appearance</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/wiki/Special:FundraiserRedirector?utm_source=donate&utm_medium=sidebar&utm_campaign=C13_en.wikipedia.org&uselang=en" class=""><span>Donate</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:CreateAccount&returnto=Sinoatrial+node" title="You are encouraged to create an account and log in; however, it is not mandatory" class=""><span>Create account</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:UserLogin&returnto=Sinoatrial+node" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o" class=""><span>Log in</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Log in and more options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Personal tools" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Personal tools</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="User menu" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/wiki/Special:FundraiserRedirector?utm_source=donate&utm_medium=sidebar&utm_campaign=C13_en.wikipedia.org&uselang=en"><span>Donate</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:CreateAccount&returnto=Sinoatrial+node" title="You are encouraged to create an account and log in; however, it is not mandatory"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Create account</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:UserLogin&returnto=Sinoatrial+node" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-Structure" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Structure"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Structure</span> </div> </a> <button aria-controls="toc-Structure-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Structure subsection</span> </button> <ul id="toc-Structure-sublist" class="vector-toc-list"> <li id="toc-Location" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Location"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.1</span> <span>Location</span> </div> </a> <ul id="toc-Location-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Microanatomy" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Microanatomy"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.2</span> <span>Microanatomy</span> </div> </a> <ul id="toc-Microanatomy-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Blood_supply" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Blood_supply"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.3</span> <span>Blood supply</span> </div> </a> <ul id="toc-Blood_supply-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Venous_drainage" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Venous_drainage"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.4</span> <span>Venous drainage</span> </div> </a> <ul id="toc-Venous_drainage-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Function" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Function"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Function</span> </div> </a> <button aria-controls="toc-Function-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Function subsection</span> </button> <ul id="toc-Function-sublist" class="vector-toc-list"> <li id="toc-Pacemaking" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Pacemaking"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Pacemaking</span> </div> </a> <ul id="toc-Pacemaking-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Nerve_supply" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Nerve_supply"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Nerve supply</span> </div> </a> <ul id="toc-Nerve_supply-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Clinical_significance" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Clinical_significance"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Clinical significance</span> </div> </a> <ul id="toc-Clinical_significance-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-History" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#History"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>History</span> </div> </a> <ul id="toc-History-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Additional_images" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Additional_images"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Additional images</span> </div> </a> <ul id="toc-Additional_images-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Sinoatrial node</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 35 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-35" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">35 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-af mw-list-item"><a href="https://af.wikipedia.org/wiki/Sino-atriale_knoop" title="Sino-atriale knoop – Afrikaans" lang="af" hreflang="af" data-title="Sino-atriale knoop" data-language-autonym="Afrikaans" data-language-local-name="Afrikaans" class="interlanguage-link-target"><span>Afrikaans</span></a></li><li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%B9%D9%82%D8%AF%D8%A9_%D8%AC%D9%8A%D8%A8%D9%8A%D8%A9_%D8%A3%D8%B0%D9%8A%D9%86%D9%8A%D8%A9" title="عقدة جيبية أذينية – Arabic" lang="ar" hreflang="ar" data-title="عقدة جيبية أذينية" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Sinoatrijski_%C4%8Dvor" title="Sinoatrijski čvor – Bosnian" lang="bs" hreflang="bs" data-title="Sinoatrijski čvor" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Node_sinusal" title="Node sinusal – Catalan" lang="ca" hreflang="ca" data-title="Node sinusal" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Sinoatri%C3%A1ln%C3%AD_uzel" title="Sinoatriální uzel – Czech" lang="cs" hreflang="cs" data-title="Sinoatriální uzel" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Sinusknoten" title="Sinusknoten – German" lang="de" hreflang="de" data-title="Sinusknoten" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/N%C3%B3dulo_sinoauricular" title="Nódulo sinoauricular – Spanish" lang="es" hreflang="es" data-title="Nódulo sinoauricular" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Nodulu_sinoaurikular" title="Nodulu sinoaurikular – Basque" lang="eu" hreflang="eu" data-title="Nodulu sinoaurikular" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%DA%AF%D8%B1%D9%87_%D8%B3%DB%8C%D9%86%D9%88%D8%B3%DB%8C-_%D8%AF%D9%87%D9%84%DB%8C%D8%B2%DB%8C" title="گره سینوسی- دهلیزی – Persian" lang="fa" hreflang="fa" data-title="گره سینوسی- دهلیزی" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/N%C5%93ud_sinusal" title="Nœud sinusal – French" lang="fr" hreflang="fr" data-title="Nœud sinusal" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/N%C3%B3_sinusal" title="Nó sinusal – Galician" lang="gl" hreflang="gl" data-title="Nó sinusal" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EA%B5%B4%EC%8B%AC%EB%B0%A9%EA%B2%B0%EC%A0%88" title="굴심방결절 – Korean" lang="ko" hreflang="ko" data-title="굴심방결절" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Nodus_sinoatrial" title="Nodus sinoatrial – Indonesian" lang="id" hreflang="id" data-title="Nodus sinoatrial" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Nodo_senoatriale" title="Nodo senoatriale – Italian" lang="it" hreflang="it" data-title="Nodo senoatriale" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%A7%D7%A9%D7%A8_%D7%94%D7%92%D7%AA_%D7%95%D7%94%D7%A4%D7%A8%D7%95%D7%96%D7%93%D7%95%D7%A8" title="קשר הגת והפרוזדור – Hebrew" lang="he" hreflang="he" data-title="קשר הגת והפרוזדור" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-kk mw-list-item"><a href="https://kk.wikipedia.org/wiki/%D2%9A%D0%BE%D0%B9%D0%BD%D0%B0%D1%83-%D0%B6%D2%AF%D1%80%D0%B5%D0%BA%D1%88%D0%B5_%D1%82%D2%AF%D0%B9%D1%96%D0%BD%D1%96" title="Қойнау-жүрекше түйіні – Kazakh" lang="kk" hreflang="kk" data-title="Қойнау-жүрекше түйіні" data-language-autonym="Қазақша" data-language-local-name="Kazakh" class="interlanguage-link-target"><span>Қазақша</span></a></li><li class="interlanguage-link interwiki-la mw-list-item"><a href="https://la.wikipedia.org/wiki/Nodus_sinuatrialis" title="Nodus sinuatrialis – Latin" lang="la" hreflang="la" data-title="Nodus sinuatrialis" data-language-autonym="Latina" data-language-local-name="Latin" class="interlanguage-link-target"><span>Latina</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Szinuszcsom%C3%B3" title="Szinuszcsomó – Hungarian" lang="hu" hreflang="hu" data-title="Szinuszcsomó" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%A1%D0%B8%D0%BD%D0%BE%D0%B0%D1%82%D1%80%D0%B8%D1%98%D0%B0%D0%BB%D0%B5%D0%BD_%D1%98%D0%B0%D0%B7%D0%BE%D0%BB" title="Синоатријален јазол – Macedonian" lang="mk" hreflang="mk" data-title="Синоатријален јазол" data-language-autonym="Македонски" data-language-local-name="Macedonian" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%8E%E0%B4%B8%E0%B5%8D.%E0%B4%8E._%E0%B4%A8%E0%B5%8B%E0%B4%A1%E0%B5%8D" title="എസ്.എ. നോഡ് – Malayalam" lang="ml" hreflang="ml" data-title="എസ്.എ. നോഡ്" data-language-autonym="മലയാളം" data-language-local-name="Malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Sinusknoop" title="Sinusknoop – Dutch" lang="nl" hreflang="nl" data-title="Sinusknoop" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E6%B4%9E%E6%88%BF%E7%B5%90%E7%AF%80" title="洞房結節 – Japanese" lang="ja" hreflang="ja" data-title="洞房結節" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Sinusknute" title="Sinusknute – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Sinusknute" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Sinusknuten" title="Sinusknuten – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Sinusknuten" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/W%C4%99ze%C5%82_zatokowo-przedsionkowy" title="Węzeł zatokowo-przedsionkowy – Polish" lang="pl" hreflang="pl" data-title="Węzeł zatokowo-przedsionkowy" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/N%C3%B3_sinusal" title="Nó sinusal – Portuguese" lang="pt" hreflang="pt" data-title="Nó sinusal" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%92%D0%BE%D0%B4%D0%B8%D1%82%D0%B5%D0%BB%D1%8C_%D1%80%D0%B8%D1%82%D0%BC%D0%B0_%D1%81%D0%B5%D1%80%D0%B4%D1%86%D0%B0" title="Водитель ритма сердца – Russian" lang="ru" hreflang="ru" data-title="Водитель ритма сердца" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-ckb mw-list-item"><a href="https://ckb.wikipedia.org/wiki/%DA%AF%D8%B1%DB%8E_%DA%AF%DB%8C%D8%B1%D9%81%D8%A7%D9%86%DB%8C_%DA%AF%D9%88%DB%8E%DA%86%DA%A9%DB%95%DA%B5%DB%95" title="گرێ گیرفانی گوێچکەڵە – Central Kurdish" lang="ckb" hreflang="ckb" data-title="گرێ گیرفانی گوێچکەڵە" data-language-autonym="کوردی" data-language-local-name="Central Kurdish" class="interlanguage-link-target"><span>کوردی</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Sinussolmuke" title="Sinussolmuke – Finnish" lang="fi" hreflang="fi" data-title="Sinussolmuke" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Sinusknuta" title="Sinusknuta – Swedish" lang="sv" hreflang="sv" data-title="Sinusknuta" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/Sinoatriyal_d%C3%BC%C4%9F%C3%BCm" title="Sinoatriyal düğüm – Turkish" lang="tr" hreflang="tr" data-title="Sinoatriyal düğüm" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%A1%D0%B8%D0%BD%D0%BE%D0%B0%D1%82%D1%80%D1%96%D0%B0%D0%BB%D1%8C%D0%BD%D0%B8%D0%B9_%D0%B2%D1%83%D0%B7%D0%BE%D0%BB" title="Синоатріальний вузол – Ukrainian" lang="uk" hreflang="uk" data-title="Синоатріальний вузол" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/N%C3%BAt_xoang" title="Nút xoang – Vietnamese" lang="vi" hreflang="vi" data-title="Nút xoang" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/%E7%AB%87%E6%88%BF%E7%B5%90" title="竇房結 – Cantonese" lang="yue" hreflang="yue" data-title="竇房結" data-language-autonym="粵語" data-language-local-name="Cantonese" class="interlanguage-link-target"><span>粵語</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E7%AA%A6%E6%88%BF%E7%BB%93" title="窦房结 – Chinese" lang="zh" hreflang="zh" data-title="窦房结" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q286020#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Sinoatrial_node" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:Sinoatrial_node" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Sinoatrial_node"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Sinoatrial_node&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Sinoatrial_node&action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/Sinoatrial_node"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Sinoatrial_node&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Sinoatrial_node&action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/Sinoatrial_node" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/Sinoatrial_node" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q"><span>Special pages</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=Sinoatrial_node&oldid=1251688092" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=Sinoatrial_node&action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&page=Sinoatrial_node&id=1251688092&wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FSinoatrial_node"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrCode&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FSinoatrial_node"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=Sinoatrial_node&action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=Sinoatrial_node&printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="wb-otherproject-link wb-otherproject-commons mw-list-item"><a href="https://commons.wikimedia.org/wiki/Category:Sinoatrial_node" hreflang="en"><span>Wikimedia Commons</span></a></li><li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q286020" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Group of cells located in the wall of the right atrium of the heart</div> <p class="mw-empty-elt"> </p> <style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox"><tbody><tr><th colspan="2" class="infobox-above" style="background-color:dimgray; color: white">Sinoatrial node</th></tr><tr><td colspan="2" class="infobox-image"><span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:Reizleitungssystem_1.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Reizleitungssystem_1.png/250px-Reizleitungssystem_1.png" decoding="async" width="250" height="377" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Reizleitungssystem_1.png/375px-Reizleitungssystem_1.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Reizleitungssystem_1.png/500px-Reizleitungssystem_1.png 2x" data-file-width="883" data-file-height="1332" /></a></span><div class="infobox-caption">Sinoatrial node shown at 1. The rest of <a href="/wiki/Electrical_conduction_system_of_the_heart" class="mw-redirect" title="Electrical conduction system of the heart">the conduction system of the heart</a> is shown in blue.</div></td></tr><tr><th colspan="2" class="infobox-header" style="background-color: #efefef">Details</th></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.25em"><a href="/wiki/Organ_system" title="Organ system">System</a></th><td class="infobox-data"><a href="/wiki/Electrical_conduction_system_of_the_heart" class="mw-redirect" title="Electrical conduction system of the heart">Electrical conduction system of the heart</a></td></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.25em"><a href="/wiki/Artery" title="Artery">Artery</a></th><td class="infobox-data"><a href="/wiki/Sinoatrial_nodal_artery" title="Sinoatrial nodal artery">Sinoatrial nodal artery</a></td></tr><tr><th colspan="2" class="infobox-header" style="background-color: #efefef">Identifiers</th></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.25em"><a href="/wiki/Latin" title="Latin">Latin</a></th><td class="infobox-data"><i>nodus sinuatrialis</i></td></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.25em">Acronym(s)</th><td class="infobox-data">SA node</td></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.25em"><a href="/wiki/Medical_Subject_Headings" title="Medical Subject Headings">MeSH</a></th><td class="infobox-data"><a rel="nofollow" class="external text" href="https://meshb.nlm.nih.gov/record/ui?ui=D012849">D012849</a></td></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.25em"><a href="/wiki/Terminologia_Anatomica" title="Terminologia Anatomica">TA98</a></th><td class="infobox-data"><a rel="nofollow" class="external text" href="https://ifaa.unifr.ch/Public/EntryPage/TA98%20Tree/Entity%20TA98%20EN/12.1.06.003%20Entity%20TA98%20EN.htm">A12.1.06.003</a></td></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.25em"><a href="/wiki/Terminologia_Anatomica" title="Terminologia Anatomica">TA2</a></th><td class="infobox-data"><a rel="nofollow" class="external text" href="https://ta2viewer.openanatomy.org/?id=3953">3953</a></td></tr><tr><th scope="row" class="infobox-label" style="padding-right:0.25em"><a href="/wiki/Foundational_Model_of_Anatomy" title="Foundational Model of Anatomy">FMA</a></th><td class="infobox-data"><a rel="nofollow" class="external text" href="https://bioportal.bioontology.org/ontologies/FMA/?p=classes&conceptid=http%3A%2F%2Fpurl.org%2Fsig%2Font%2Ffma%2Ffma9477">9477</a></td></tr><tr><td colspan="2" class="infobox-below"><a href="/wiki/Anatomical_terminology" title="Anatomical terminology">Anatomical terminology</a><div style="text-align: right;"><small class="noprint">[<a href="https://www.wikidata.org/wiki/Q286020" class="extiw" title="d:Q286020">edit on Wikidata</a>]</small></div></td></tr></tbody></table> <p>The <b>sinoatrial node</b> (also known as the <b>sinuatrial node</b>, <b>SA node</b> or <b>sinus node</b>) is an <a href="/wiki/Ellipse" title="Ellipse">oval shaped</a> region of special <a href="/wiki/Cardiac_muscle" title="Cardiac muscle">cardiac muscle</a> in the upper back wall of the <a href="/wiki/Right_atrium" class="mw-redirect" title="Right atrium">right atrium</a> made up of <a href="/wiki/Cell_(biology)" title="Cell (biology)">cells</a> known as <a href="/wiki/Pacemaker_cell" class="mw-redirect" title="Pacemaker cell">pacemaker cells</a>. The sinus node is approximately 15 <a href="/wiki/Millimetre" title="Millimetre">mm</a> long, 3 mm wide, and 1 mm thick, located directly below and to the side of the <a href="/wiki/Superior_vena_cava" title="Superior vena cava">superior vena cava</a>.<sup id="cite_ref-Hall_1-0" class="reference"><a href="#cite_note-Hall-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> </p><p>These cells produce an <a href="/wiki/Action_potential" title="Action potential">electrical impulse</a> known as a <a href="/wiki/Cardiac_action_potential" title="Cardiac action potential">cardiac action potential</a> that travels through the <a href="/wiki/Electrical_conduction_system_of_the_heart" class="mw-redirect" title="Electrical conduction system of the heart">electrical conduction system of the heart</a>, causing it to <a href="/wiki/Muscle_contraction" title="Muscle contraction">contract</a>. In a healthy heart, the SA node continuously produces action potentials, setting the rhythm of the heart (<a href="/wiki/Sinus_rhythm" title="Sinus rhythm">sinus rhythm</a>), and so is known as the heart's <a href="/wiki/Cardiac_pacemaker" title="Cardiac pacemaker">natural pacemaker</a>. The rate of action potentials produced (and therefore the <a href="/wiki/Heart_rate" title="Heart rate">heart rate</a>) is influenced by the <a href="/wiki/Nerves" class="mw-redirect" title="Nerves">nerves</a> that supply it.<sup id="cite_ref-Monfredi_2-0" class="reference"><a href="#cite_note-Monfredi-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Structure">Structure</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=1" title="Edit section: Structure"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The sinoatrial node is an <a href="/wiki/Ellipse" title="Ellipse">oval-shaped</a> structure that is approximately 15 <a href="/wiki/Millimetre" title="Millimetre">mm</a> long, 3 mm wide, and 1 mm thick, located directly below and to the side of the <a href="/wiki/Superior_vena_cava" title="Superior vena cava">superior vena cava</a>.<sup id="cite_ref-Hall_1-1" class="reference"><a href="#cite_note-Hall-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> The size can vary but is usually between 10-30 mm long, 5–7 mm wide, and 1–2 mm deep.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Location">Location</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=2" title="Edit section: Location"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The SA node is located in the wall (<a href="/wiki/Epicardium" class="mw-redirect" title="Epicardium">epicardium</a>) of the <a href="/wiki/Atrium_(heart)" title="Atrium (heart)">right atrium</a>, laterally to the entrance of the <a href="/wiki/Superior_vena_cava" title="Superior vena cava">superior vena cava</a> in a region called the <a href="/wiki/Sinus_venosus" title="Sinus venosus">sinus venarum</a> (hence <i><a href="https://en.wiktionary.org/wiki/sino-#Prefix" class="extiw" title="wikt:sino-">sino-</a></i> + <i><a href="https://en.wiktionary.org/wiki/atrial#Adjective" class="extiw" title="wikt:atrial">atrial</a>)</i>.<sup id="cite_ref-Dorlands_5-0" class="reference"><a href="#cite_note-Dorlands-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> It is positioned roughly between a groove called the <a href="/wiki/Crista_terminalis" title="Crista terminalis">crista terminalis</a> located on the internal surface of the <a href="/wiki/Heart" title="Heart">heart</a> and the corresponding <a href="/wiki/Terminal_sulcus_(heart)" title="Terminal sulcus (heart)">sulcus terminalis</a>, on the external surface.<sup id="cite_ref-Monfredi_2-1" class="reference"><a href="#cite_note-Monfredi-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> These grooves run between the entrance of the <a href="/wiki/Superior_vena_cava" title="Superior vena cava">superior vena cava</a> and the <a href="/wiki/Inferior_vena_cava" title="Inferior vena cava">inferior vena cava</a>. </p> <div class="mw-heading mw-heading3"><h3 id="Microanatomy">Microanatomy</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=3" title="Edit section: Microanatomy"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Sinoatrial_node_2_low_mag.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/de/Sinoatrial_node_2_low_mag.jpg/220px-Sinoatrial_node_2_low_mag.jpg" decoding="async" width="220" height="175" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/de/Sinoatrial_node_2_low_mag.jpg/330px-Sinoatrial_node_2_low_mag.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/de/Sinoatrial_node_2_low_mag.jpg/440px-Sinoatrial_node_2_low_mag.jpg 2x" data-file-width="2588" data-file-height="2054" /></a><figcaption>Figure 2: Low magnification <a href="/wiki/H%26E_stain" title="H&E stain">stained</a> <a href="/wiki/Histology" title="Histology">image</a> of the SA node (center-right on image) and its surrounding tissue. The SA node surrounds the <a href="/wiki/Sinoatrial_nodal_artery" title="Sinoatrial nodal artery">sinoatrial nodal artery</a>, seen as the open <a href="/wiki/Lumen_(anatomy)" title="Lumen (anatomy)">lumen</a>. Cardiac muscle cells of the right atrium can be seen to the left of the node, and fat tissue to the right.</figcaption></figure> <p>The cells of the SA node are spread out within a mesh of <a href="/wiki/Connective_tissue" title="Connective tissue">connective tissue</a>, containing <a href="/wiki/Nerves" class="mw-redirect" title="Nerves">nerves</a>, <a href="/wiki/Blood_vessels" class="mw-redirect" title="Blood vessels">blood vessels</a>, <a href="/wiki/Collagen" title="Collagen">collagen</a> and <a href="/wiki/Fat" title="Fat">fat</a>. Immediately surrounding the SA node cells are paranodal cells.<sup id="cite_ref-Monfredi_2-2" class="reference"><a href="#cite_note-Monfredi-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> These cells have structures intermediate between that of the SA node cells and the rest of the <a href="/wiki/Atrium_(heart)" title="Atrium (heart)">atrium</a>.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> The connective tissue, along with the paranodal cells, insulate the SA node from the rest of the atrium, preventing the electrical activity of the atrial cells from affecting the SA node cells.<sup id="cite_ref-Monfredi_2-3" class="reference"><a href="#cite_note-Monfredi-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> The SA node cells are smaller and paler than the surrounding <a href="/wiki/Atrium_(heart)" title="Atrium (heart)">atrial cells</a>, with the average cell being around 8 micrometers in diameter and 20-30 micrometers in length (1 micrometer= 0.000001 meter).<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> Unlike the atrial cells, SA node cells contain fewer <a href="/wiki/Mitochondrion" title="Mitochondrion">mitochondria</a> and <a href="/wiki/Myofibers" class="mw-redirect" title="Myofibers">myofibers</a>, as well as a smaller <a href="/wiki/Sarcoplasmic_reticulum" title="Sarcoplasmic reticulum">sarcoplasmic reticulum</a>. This means that the SA node cells are less equipped to contract compared to the <a href="/wiki/Atrium_(heart)" title="Atrium (heart)">atrial</a> and <a href="/wiki/Ventricle_(heart)" title="Ventricle (heart)">ventricular</a> cells.<sup id="cite_ref-Boyett_8-0" class="reference"><a href="#cite_note-Boyett-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> </p><p>Action potentials pass from one <a href="/wiki/Heart" title="Heart">cardiac cell</a> to the next through pores known as gap junctions. These gap junctions are made of proteins called <a href="/wiki/Connexin" title="Connexin">connexins</a>. There are fewer gap junctions within the SA node and they are smaller in size. This is again important in insulating the SA node from the surrounding atrial cells.<sup id="cite_ref-Monfredi_2-4" class="reference"><a href="#cite_note-Monfredi-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Boyett_8-1" class="reference"><a href="#cite_note-Boyett-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Blood_supply">Blood supply</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=4" title="Edit section: Blood supply"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The sinoatrial node receives its blood supply from the <a href="/wiki/Sinoatrial_nodal_artery" title="Sinoatrial nodal artery">sinoatrial nodal artery</a>. This blood supply, however, can differ hugely between individuals. For example, in most humans, this is a single <a href="/wiki/Artery" title="Artery">artery</a>, although in some cases there have been either 2 or 3 sinoatrial node arteries supplying the SA node. Also, the SA node artery mainly originates as a branch of the <a href="/wiki/Right_coronary_artery" title="Right coronary artery">right coronary artery</a>; however in some individuals it has arisen from the <a href="/wiki/Circumflex_branch_of_left_coronary_artery" title="Circumflex branch of left coronary artery">circumflex artery</a>, which is a branch of the <a href="/wiki/Left_coronary_artery" title="Left coronary artery">left coronary artery</a>. Finally, the SA node artery commonly passes behind the <a href="/wiki/Superior_vena_cava" title="Superior vena cava">superior vena cava</a>, before reaching the SA node; however in some instances it passes in front. Despite these many differences, there doesn't appear to be any advantage to how many sinoatrial nodal arteries an individual has, or where they originate.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Venous_drainage">Venous drainage</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=5" title="Edit section: Venous drainage"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>There are no large <a href="/wiki/Veins" class="mw-redirect" title="Veins">veins</a> that drain blood away from the SA node. Instead, smaller <a href="/wiki/Venule" title="Venule">venules</a> drain the blood directly into the <a href="/wiki/Atrium_(heart)" title="Atrium (heart)">right atrium</a>.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Function">Function</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=6" title="Edit section: Function"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Pacemaking">Pacemaking</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=7" title="Edit section: Pacemaking"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Cardiac_pacemaker" title="Cardiac pacemaker">Cardiac pacemaker</a></div> <p>The main role of a sinoatrial node cell is to initiate action potentials of the heart that can pass through <a href="/wiki/Cardiac_muscle_cell" class="mw-redirect" title="Cardiac muscle cell">cardiac muscle cells</a> and cause contraction. An action potential is a rapid change in <a href="/wiki/Membrane_potential" title="Membrane potential">membrane potential</a>, produced by the movement of charged atoms (<a href="/wiki/Ions" class="mw-redirect" title="Ions">ions</a>). In the absence of stimulation, non-pacemaker cells (including the <a href="/wiki/Ventricle_(heart)" title="Ventricle (heart)">ventricular</a> and <a href="/wiki/Atrium_(heart)" title="Atrium (heart)">atrial cells</a>) have a relatively constant membrane potential; this is known as a <a href="/wiki/Resting_potential" title="Resting potential">resting potential</a>. This resting phase (see <a href="/wiki/Cardiac_action_potential" title="Cardiac action potential">cardiac action potential, phase 4</a>) ends when an action potential reaches the cell. This produces a positive change in membrane potential, known as <a href="/wiki/Depolarization" title="Depolarization">depolarization</a>, which is propagated throughout the heart and initiates <a href="/wiki/Muscle_contraction" title="Muscle contraction">muscle contraction</a>. Pacemaker cells, however, do not have a resting potential. Instead, immediately after <a href="/wiki/Repolarization" title="Repolarization">repolarization</a>, the membrane potential of these cells begins to depolarise again automatically, a phenomenon known as the <a href="/wiki/Pacemaker_potential" title="Pacemaker potential">pacemaker potential</a>. Once the pacemaker potential reaches a set value, the <a href="/wiki/Threshold_potential" title="Threshold potential">threshold potential</a>, it produces an action potential.<sup id="cite_ref-Monfredi_2-5" class="reference"><a href="#cite_note-Monfredi-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> Other cells within the heart (including the <a href="/wiki/Purkinje_fibers" title="Purkinje fibers">Purkinje fibers</a><sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> and <a href="/wiki/Atrioventricular_node" title="Atrioventricular node">atrioventricular node</a>) can also initiate action potentials; however, they do so at a slower rate and therefore, if the SA node is functioning properly, its action potentials usually override those that would be produced by other tissues.<sup id="cite_ref-Vassalle1977_12-0" class="reference"><a href="#cite_note-Vassalle1977-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </p><p>Outlined below are the 3 phases of a sinoatrial node action potential. In the <a href="/wiki/Cardiac_action_potential" title="Cardiac action potential">cardiac action potential</a>, there are 5 phases (labelled 0-4), however pacemaker action potentials do not have an obvious phase 1 or 2. </p><p><b>Phase 4</b> </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Sinoatrial_action_potential.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Sinoatrial_action_potential.jpg/220px-Sinoatrial_action_potential.jpg" decoding="async" width="220" height="249" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Sinoatrial_action_potential.jpg/330px-Sinoatrial_action_potential.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Sinoatrial_action_potential.jpg/440px-Sinoatrial_action_potential.jpg 2x" data-file-width="793" data-file-height="899" /></a><figcaption>Figure 3: Sinoatrial node action potential waveform, outlining major ion currents involved (downward deflection indicates ions moving into the cell, upwards deflection indicates ions flowing out of the cell).</figcaption></figure> <p>This phase is also known as the <a href="/wiki/Pacemaker_potential" title="Pacemaker potential">pacemaker potential</a>. Immediately following repolarization, when the membrane potential is very negative (it is hyperpolarised), the voltage slowly begins to increase. This is initially due to the closing of <a href="/wiki/Potassium_channel" title="Potassium channel">potassium channels</a>, which reduces the flow of <a href="/wiki/Potassium" title="Potassium">potassium</a> ions (I<sub>k</sub>) out of the cell (see phase 2, below).<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> Hyperpolarization also causes activation of <a href="/wiki/HCN_channel" title="HCN channel">hyperpolarisation-activated cyclic nucleotide–gated (HCN) channels</a>. The activation of ion channels at very negative membrane potentials is unusual, therefore the flow of <a href="/wiki/Sodium" title="Sodium">sodium (Na<sup>+</sup>)</a> and some K<sup>+</sup> through the activated HCN channel is referred to as a <i><a href="/wiki/Funny_current" class="mw-redirect" title="Funny current">funny current</a></i> (I<sub>f</sub>).<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> This funny current causes the membrane potential of the cell to gradually increase, as the positive charge (Na<sup>+</sup> and K<sup>+</sup>) is flowing into the cell. Another mechanism involved in pacemaker potential is known as the <a href="/wiki/Calcium" title="Calcium">calcium</a> clock. This refers to the spontaneous release of calcium from the <a href="/wiki/Sarcoplasmic_reticulum" title="Sarcoplasmic reticulum">sarcoplasmic reticulum</a> (a calcium store) into the cytoplasm, also known as <a href="/wiki/Calcium_sparks" title="Calcium sparks">calcium sparks</a>. This increase in calcium within the cell then activates a <a href="/wiki/Sodium-calcium_exchanger" title="Sodium-calcium exchanger">sodium-calcium exchanger</a> (NCX), which removes one Ca<sup>2+</sup> from the cell, and exchanges it for 3 Na<sup>+</sup> into the cell (therefore removing a charge of +2 from the cell, but allowing a charge of +3 to enter the cell) further increasing the membrane potential. Calcium later reenters the cell via <a href="/wiki/SERCA" title="SERCA">SERCA</a> and <a href="/wiki/Calcium_channel" title="Calcium channel">calcium channels</a> located on the cell membrane.<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> The increase in membrane potential produced by these mechanisms, activates <a href="/wiki/T-type_calcium_channel" title="T-type calcium channel">T-type calcium channels</a> and then <a href="/wiki/L-type_calcium_channels" class="mw-redirect" title="L-type calcium channels">L-type calcium channels</a> (which open very slowly). These channels allow a flow of Ca<sup>2+</sup> into the cell, making the membrane potential even more positive. </p><p><b>Phase 0</b> </p><p>This is the depolarization phase. When the membrane potential reaches the threshold potential (around -20 to -50 mV), the cell begins to rapidly depolarise (become more positive).<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> This is mainly due to the flow of Ca<sup>2+</sup> through L-type calcium channels, which are now fully open. During this stage, T-type calcium channels and HCN channels deactivate. </p><p><b>Phase 3</b> </p><p>This phase is the repolarization phase. This occurs due to the inactivation of L-type calcium channels (preventing the movement of Ca<sup>2+</sup> into the cell) and the activation of potassium channels, which allows the flow of K<sup>+</sup> out of the cell, making the membrane potential more negative.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Nerve_supply">Nerve supply</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=8" title="Edit section: Nerve supply"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/Heart_rate" title="Heart rate">Heart rate</a> depends on the rate at which the sinoatrial node produces <a href="/wiki/Cardiac_action_potential" title="Cardiac action potential">action potentials</a>. At rest, heart rate is between 60 and 100 beats per minute. This is a result of the activity of two sets of nerves, one acting to slow down action potential production (these are <a href="/wiki/Parasympathetic_nervous_system" title="Parasympathetic nervous system">parasympathetic nerves</a>) and the other acting to speed up action potential production (<a href="/wiki/Sympathetic_nervous_system" title="Sympathetic nervous system">sympathetic nerves</a>).<sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> </p><p>Modulation of heart rate by ANS is carried by two types of channel: <a href="/wiki/Inward-rectifier_potassium_channel" title="Inward-rectifier potassium channel">Kir</a> and <a href="/wiki/HCN_channel" title="HCN channel">HCN</a> (members of the <a href="/wiki/Cyclic_nucleotide%E2%80%93gated_ion_channel" title="Cyclic nucleotide–gated ion channel">CNG gated channels</a>). </p><p>The sympathetic nerves begin in the <a href="/wiki/Thoracic_nerves" class="mw-redirect" title="Thoracic nerves">thoracic</a> region of the spinal cord (in particular T1-T4). These nerves release a neurotransmitter called <a href="/wiki/Norepinephrine" title="Norepinephrine">noradrenaline (NA)</a>. This binds to a receptor on the SA node membrane, called a <a href="/wiki/Beta-1_adrenergic_receptor" title="Beta-1 adrenergic receptor">beta-1adrenoceptor</a>. Binding of NA to this receptor activates a G-protein (in particular a <a href="/wiki/Gs_alpha_subunit" title="Gs alpha subunit">G<sub>s</sub>-Protein</a>, S for stimulatory) which initiates a series of reactions (known as the <a href="/wiki/CAMP-dependent_pathway" title="CAMP-dependent pathway">cAMP pathway</a>) that results in the production of a molecule called <a href="/wiki/Cyclic_adenosine_monophosphate" title="Cyclic adenosine monophosphate">cyclic adenosinemonophosphate (cAMP)</a>. This cAMP binds to the HCN channel (see above). Binding of cAMP to the HCN increases the flow of Na<sup>+</sup> and K<sup>+</sup> into the cell, speeding up the pacemaker potential, so producing action potentials at a quicker rate and increasing heart rate.<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> An increase in heart rate is known as positive <a href="/wiki/Chronotropic" title="Chronotropic">chronotropy</a>. </p><p>The <a href="/wiki/Parasympathetic_nervous_system" title="Parasympathetic nervous system">parasympathetic nerves</a> supplying the SA node (in particular the <a href="/wiki/Vagus_nerves" class="mw-redirect" title="Vagus nerves">Vagus nerves</a>) originate in the <a href="/wiki/Brain" title="Brain">brain</a>. These nerves release a neurotransmitter called <a href="/wiki/Acetylcholine" title="Acetylcholine">acetylcholine (ACh)</a>. ACh binds to a receptor called an <a href="/wiki/Muscarinic_acetylcholine_receptor_M2" title="Muscarinic acetylcholine receptor M2">M2 muscarinic receptor</a>, located on the SA node membrane. Activation of this M2 receptor then activates a protein called a G-protein (in particular <a href="/wiki/Gi_alpha_subunit" title="Gi alpha subunit">G<sub>i</sub> protein</a>, i for inhibitory). Activation of this G-protein blocks the cAMP pathway, reducing its effects, therefore inhibiting sympathetic activity and slowing action potential production. The G-protein also activates a potassium channel <a href="/wiki/KCNJ3" title="KCNJ3">GIRK-1</a> and <a href="/wiki/KCNJ5" title="KCNJ5">GIRK-4</a>, which allows K<sup>+</sup> to flow out of the cell, making the membrane potential more negative and slowing the pacemaker potential, therefore decreasing the rate of action potential production and therefore decreasing heart rate.<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> A decrease in heart rate is known as negative <a href="/wiki/Chronotropic" title="Chronotropic">chronotropy</a>. </p><p>The first cell to produce the action potential in the SA node isn't always the same; this is known as pacemaker shift. In certain species of animals—for example, in dogs—a superior shift (i.e., the cell that produces the fastest action potential in the SA node is higher than previously) usually produces an increased heart rate whereas an inferior shift (i.e. the cell producing the fastest action potential within the SA node is further down than previously) produces a decreased heart rate.<sup id="cite_ref-Monfredi_2-6" class="reference"><a href="#cite_note-Monfredi-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Clinical_significance">Clinical significance</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=9" title="Edit section: Clinical significance"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/Sinus_node_dysfunction" title="Sinus node dysfunction">Sinus node dysfunction</a> also known as <i>sick sinus syndrome</i> is a group of <a href="/wiki/Arrhythmia" title="Arrhythmia">irregular heartbeat</a> conditions caused by faulty electrical signals of the heart. When the heart's sinoatrial node is defective, the heart's rhythms become abnormal—typically too slow or exhibiting pauses in its function or a combination, and very rarely faster than normal.<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> </p><p>Blockage of the arterial blood supply to the SA node (most commonly due to a <a href="/wiki/Myocardial_infarction" title="Myocardial infarction">myocardial infarction</a> or progressive <a href="/wiki/Coronary_artery_disease" title="Coronary artery disease">coronary artery disease</a>) can therefore cause <a href="/wiki/Ischemia" title="Ischemia">ischemia</a> and cell death in the SA node. This can disrupt the electrical pacemaker function of the SA node, and can result in sinus node dysfunction. </p><p>If the SA node does not function or the impulse generated in the <a href="/wiki/Sinoatrial_block" title="Sinoatrial block">SA node is blocked</a> before it travels down the electrical conduction system, a group of cells further down the heart will become its pacemaker.<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=10" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The sinoatrial node was first discovered by a young medical student, <a href="/wiki/Martin_Flack" title="Martin Flack">Martin Flack</a>, in the heart of a <a href="/wiki/Mole_(animal)" title="Mole (animal)">mole</a>, whilst his mentor, Sir <a href="/wiki/Arthur_Keith" title="Arthur Keith">Arthur Keith</a>, was on a bicycle ride with his wife. They made the discovery in a makeshift laboratory set up in a farmhouse in <a href="/wiki/Kent" title="Kent">Kent</a>, <a href="/wiki/England" title="England">England</a>, called Mann's Place. Their discovery was published in 1907.<sup id="cite_ref-heart_23-0" class="reference"><a href="#cite_note-heart-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-pmid17556667_24-0" class="reference"><a href="#cite_note-pmid17556667-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Additional_images">Additional images</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=11" title="Edit section: Additional images"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul class="gallery mw-gallery-traditional"> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:Reizleitungssystem_1.png" class="mw-file-description" title="Heart; conduction system (SA node labeled 1)"><img alt="Heart; conduction system (SA node labeled 1)" src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Reizleitungssystem_1.png/79px-Reizleitungssystem_1.png" decoding="async" width="79" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Reizleitungssystem_1.png/119px-Reizleitungssystem_1.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Reizleitungssystem_1.png/159px-Reizleitungssystem_1.png 2x" data-file-width="883" data-file-height="1332" /></a></span></div> <div class="gallerytext">Heart; conduction system (SA node labeled 1)</div> </li> <li class="gallerybox" style="width: 155px"> <div class="thumb" style="width: 150px; height: 150px;"><span typeof="mw:File"><a href="/wiki/File:Gray501.png" class="mw-file-description" title="Schematic representation of the atrioventricular bundle"><img alt="Schematic representation of the atrioventricular bundle" src="//upload.wikimedia.org/wikipedia/commons/thumb/9/92/Gray501.png/99px-Gray501.png" decoding="async" width="99" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/92/Gray501.png/149px-Gray501.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/92/Gray501.png/199px-Gray501.png 2x" data-file-width="400" data-file-height="483" /></a></span></div> <div class="gallerytext">Schematic representation of the atrioventricular bundle</div> </li> </ul> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=12" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">This article uses <a href="/wiki/Anatomical_terminology" title="Anatomical terminology">anatomical terminology</a>.</div> <ul><li><a href="/wiki/Cardiac_pacemaker" title="Cardiac pacemaker">Cardiac pacemaker</a></li> <li><a href="/wiki/Cardiology" title="Cardiology">Cardiology</a></li> <li><a href="/wiki/Heart_block" title="Heart block">Heart block</a></li> <li><a href="/wiki/Sinus_bradycardia" title="Sinus bradycardia">Sinus bradycardia</a></li> <li><a href="/wiki/Sinus_tachycardia" title="Sinus tachycardia">Sinus tachycardia</a></li> <li><a href="/wiki/Cardiothoracic_Surgery" class="mw-redirect" title="Cardiothoracic Surgery">Cardiothoracic Surgery</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=13" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-Hall-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-Hall_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Hall_1-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFHall2011" class="citation book cs1">Hall, John E. (2011). <i>Guyton and Hall textbook of medical physiology</i> (Twelfth ed.). Philadelphia, Pa. p. 115. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9781416045748" title="Special:BookSources/9781416045748"><bdi>9781416045748</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Guyton+and+Hall+textbook+of+medical+physiology&rft.place=Philadelphia%2C+Pa.&rft.pages=115&rft.edition=Twelfth&rft.date=2011&rft.isbn=9781416045748&rft.aulast=Hall&rft.aufirst=John+E.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span><span class="cs1-maint citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_book" title="Template:Cite book">cite book</a>}}</code>: CS1 maint: location missing publisher (<a href="/wiki/Category:CS1_maint:_location_missing_publisher" title="Category:CS1 maint: location missing publisher">link</a>)</span></span> </li> <li id="cite_note-Monfredi-2"><span class="mw-cite-backlink">^ <a href="#cite_ref-Monfredi_2-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Monfredi_2-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Monfredi_2-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-Monfredi_2-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-Monfredi_2-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-Monfredi_2-5"><sup><i><b>f</b></i></sup></a> <a href="#cite_ref-Monfredi_2-6"><sup><i><b>g</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMonfrediDobrzynskiMondalBoyett2010" class="citation journal cs1">Monfredi, O.; Dobrzynski, H.; Mondal, T.; Boyett, M.R.; Morris, G.M. (2010). "The anatomy and physiology of the Sinoatrial Node-A contemporary review". <i>Pacing and Clinical Electrophysiology</i>. <b>33</b> (11): 1392–1406. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1111%2Fj.1540-8159.2010.02838.x">10.1111/j.1540-8159.2010.02838.x</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/20946278">20946278</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:22207608">22207608</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Pacing+and+Clinical+Electrophysiology&rft.atitle=The+anatomy+and+physiology+of+the+Sinoatrial+Node-A+contemporary+review&rft.volume=33&rft.issue=11&rft.pages=1392-1406&rft.date=2010&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A22207608%23id-name%3DS2CID&rft_id=info%3Apmid%2F20946278&rft_id=info%3Adoi%2F10.1111%2Fj.1540-8159.2010.02838.x&rft.aulast=Monfredi&rft.aufirst=O.&rft.au=Dobrzynski%2C+H.&rft.au=Mondal%2C+T.&rft.au=Boyett%2C+M.R.&rft.au=Morris%2C+G.M.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCsepeZhaoHansenLi2017" class="citation journal cs1">Csepe, Thomas A.; Zhao, Jichao; Hansen, Brian J.; Li, Ning; Sul, Lidiya V.; Lim, Praise; Wang, Yufeng; Simonetti, Orlando P.; Kilic, Ahmet (1 March 2017). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808362">"Human Sinoatrial Node Structure: 3D Microanatomy of Sinoatrial Conduction Pathways"</a>. <i>Progress in Biophysics and Molecular Biology</i>. <b>120</b> (1–3): 164–178. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.pbiomolbio.2015.12.011">10.1016/j.pbiomolbio.2015.12.011</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0079-6107">0079-6107</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808362">4808362</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/26743207">26743207</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Progress+in+Biophysics+and+Molecular+Biology&rft.atitle=Human+Sinoatrial+Node+Structure%3A+3D+Microanatomy+of+Sinoatrial+Conduction+Pathways&rft.volume=120&rft.issue=1%E2%80%933&rft.pages=164-178&rft.date=2017-03-01&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC4808362%23id-name%3DPMC&rft.issn=0079-6107&rft_id=info%3Apmid%2F26743207&rft_id=info%3Adoi%2F10.1016%2Fj.pbiomolbio.2015.12.011&rft.aulast=Csepe&rft.aufirst=Thomas+A.&rft.au=Zhao%2C+Jichao&rft.au=Hansen%2C+Brian+J.&rft.au=Li%2C+Ning&rft.au=Sul%2C+Lidiya+V.&rft.au=Lim%2C+Praise&rft.au=Wang%2C+Yufeng&rft.au=Simonetti%2C+Orlando+P.&rft.au=Kilic%2C+Ahmet&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC4808362&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFChandlerAslanidiBuckleyInada2011" class="citation journal cs1">Chandler, N.; Aslanidi, O.; Buckley, D.; Inada, S.; Birchall, S.; Atkinson, A.; Kirk, D.; Monfredi, O.; Molenaar, P.; Anderson, R.; Sharma, V.; Sigg, D.; Zhang, H.; Boyett, M.; Dobrzynski, H. (2011). "Computer three-dimensional anatomical recon-struction of the human sinus node and a novel paranodal area". <i>Anatomical Record</i>. <b>294</b> (6): 970–9. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Far.21379">10.1002/ar.21379</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/21538926">21538926</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:45464625">45464625</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Anatomical+Record&rft.atitle=Computer+three-dimensional+anatomical+recon-struction+of+the+human+sinus+node+and+a+novel+paranodal+area&rft.volume=294&rft.issue=6&rft.pages=970-9&rft.date=2011&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A45464625%23id-name%3DS2CID&rft_id=info%3Apmid%2F21538926&rft_id=info%3Adoi%2F10.1002%2Far.21379&rft.aulast=Chandler&rft.aufirst=N.&rft.au=Aslanidi%2C+O.&rft.au=Buckley%2C+D.&rft.au=Inada%2C+S.&rft.au=Birchall%2C+S.&rft.au=Atkinson%2C+A.&rft.au=Kirk%2C+D.&rft.au=Monfredi%2C+O.&rft.au=Molenaar%2C+P.&rft.au=Anderson%2C+R.&rft.au=Sharma%2C+V.&rft.au=Sigg%2C+D.&rft.au=Zhang%2C+H.&rft.au=Boyett%2C+M.&rft.au=Dobrzynski%2C+H.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-Dorlands-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-Dorlands_5-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFElsevier" class="citation cs2"><a href="/wiki/Elsevier" title="Elsevier">Elsevier</a>, <a rel="nofollow" class="external text" href="http://dorlands.com/"><i>Dorland's Illustrated Medical Dictionary</i></a>, Elsevier.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Dorland%27s+Illustrated+Medical+Dictionary&rft.pub=Elsevier&rft.au=Elsevier&rft_id=http%3A%2F%2Fdorlands.com%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFChandlerGreenerTellezInada2009" class="citation journal cs1">Chandler, NJ; Greener, ID; Tellez, JO; Inada, S; Musa, H; Molenaar, P; Difrancesco, D; et al. (2009). <a rel="nofollow" class="external text" href="https://doi.org/10.1161%2Fcirculationaha.108.804369">"Molecular architecture of the human sinus node: Insights into the function of the cardiac pacemaker"</a>. <i>Circulation</i>. <b>119</b> (12): 1562–1575. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1161%2Fcirculationaha.108.804369">10.1161/circulationaha.108.804369</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/19289639">19289639</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Circulation&rft.atitle=Molecular+architecture+of+the+human+sinus+node%3A+Insights+into+the+function+of+the+cardiac+pacemaker&rft.volume=119&rft.issue=12&rft.pages=1562-1575&rft.date=2009&rft_id=info%3Adoi%2F10.1161%2Fcirculationaha.108.804369&rft_id=info%3Apmid%2F19289639&rft.aulast=Chandler&rft.aufirst=NJ&rft.au=Greener%2C+ID&rft.au=Tellez%2C+JO&rft.au=Inada%2C+S&rft.au=Musa%2C+H&rft.au=Molenaar%2C+P&rft.au=Difrancesco%2C+D&rft_id=https%3A%2F%2Fdoi.org%2F10.1161%252Fcirculationaha.108.804369&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHonjoBoyettKodamaToyama1996" class="citation journal cs1">Honjo, H.; Boyett, M.R.; Kodama, I.; Toyama, J. (1996). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1160865">"Correlation between electrical activity and the size of rabbit sino-atrial node cells"</a>. <i>The Journal of Physiology</i>. <b>496</b> (3): 795–808. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1113%2Fjphysiol.1996.sp021728">10.1113/jphysiol.1996.sp021728</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1160865">1160865</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/8930845">8930845</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Journal+of+Physiology&rft.atitle=Correlation+between+electrical+activity+and+the+size+of+rabbit+sino-atrial+node+cells&rft.volume=496&rft.issue=3&rft.pages=795-808&rft.date=1996&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC1160865%23id-name%3DPMC&rft_id=info%3Apmid%2F8930845&rft_id=info%3Adoi%2F10.1113%2Fjphysiol.1996.sp021728&rft.aulast=Honjo&rft.aufirst=H.&rft.au=Boyett%2C+M.R.&rft.au=Kodama%2C+I.&rft.au=Toyama%2C+J.&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC1160865&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-Boyett-8"><span class="mw-cite-backlink">^ <a href="#cite_ref-Boyett_8-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Boyett_8-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBoyettKodama2000" class="citation journal cs1">Boyett, Honjo; Kodama, I. (2000). <a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fs0008-6363%2800%2900135-8">"The sinoatrial node, a heterogeneous pace-maker structure"</a>. <i>Cardiovascular Research</i>. <b>47</b> (4): 658–87. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fs0008-6363%2800%2900135-8">10.1016/s0008-6363(00)00135-8</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/10974216">10974216</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Cardiovascular+Research&rft.atitle=The+sinoatrial+node%2C+a+heterogeneous+pace-maker+structure&rft.volume=47&rft.issue=4&rft.pages=658-87&rft.date=2000&rft_id=info%3Adoi%2F10.1016%2Fs0008-6363%2800%2900135-8&rft_id=info%3Apmid%2F10974216&rft.aulast=Boyett&rft.aufirst=Honjo&rft.au=Kodama%2C+I.&rft_id=https%3A%2F%2Fdoi.org%2F10.1016%252Fs0008-6363%252800%252900135-8&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFVikseHenryRoyRamakrishnan2016b" class="citation journal cs1">Vikse, J.; Henry, B.M.; Roy, J.; Ramakrishnan, P.K.; Hsieh, W.C.; Walocha, J.A.; Tomaszewski, K.A. (2016b). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4743947">"Anatomical variations in the Sinoatrial Nodal artery: A Meta-Analysis and clinical considerations"</a>. <i>PLOS ONE</i>. <b>11</b> (2): e0148331. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2016PLoSO..1148331V">2016PLoSO..1148331V</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1371%2Fjournal.pone.0148331">10.1371/journal.pone.0148331</a></span>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4743947">4743947</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/26849441">26849441</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=PLOS+ONE&rft.atitle=Anatomical+variations+in+the+Sinoatrial+Nodal+artery%3A+A+Meta-Analysis+and+clinical+considerations&rft.volume=11&rft.issue=2&rft.pages=e0148331&rft.date=2016&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC4743947%23id-name%3DPMC&rft_id=info%3Apmid%2F26849441&rft_id=info%3Adoi%2F10.1371%2Fjournal.pone.0148331&rft_id=info%3Abibcode%2F2016PLoSO..1148331V&rft.aulast=Vikse&rft.aufirst=J.&rft.au=Henry%2C+B.M.&rft.au=Roy%2C+J.&rft.au=Ramakrishnan%2C+P.K.&rft.au=Hsieh%2C+W.C.&rft.au=Walocha%2C+J.A.&rft.au=Tomaszewski%2C+K.A.&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC4743947&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAndersonHoAnderson1979" class="citation journal cs1">Anderson, K.R.; Ho, S.Y.; Anderson, R.H. (1979). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC514694">"Location and vascular supply of sinus node in human heart"</a>. <i>Heart</i>. <b>41</b> (1): 28–32. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1136%2Fhrt.41.1.28">10.1136/hrt.41.1.28</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC514694">514694</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/426954">426954</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Heart&rft.atitle=Location+and+vascular+supply+of+sinus+node+in+human+heart&rft.volume=41&rft.issue=1&rft.pages=28-32&rft.date=1979&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC514694%23id-name%3DPMC&rft_id=info%3Apmid%2F426954&rft_id=info%3Adoi%2F10.1136%2Fhrt.41.1.28&rft.aulast=Anderson&rft.aufirst=K.R.&rft.au=Ho%2C+S.Y.&rft.au=Anderson%2C+R.H.&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC514694&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFTsienCarpenter1978" class="citation journal cs1">Tsien, R. W.; Carpenter, D. O. (1 June 1978). "Ionic mechanisms of pacemaker activity in cardiac Purkinje fibers". <i>Federation Proceedings</i>. <b>37</b> (8): 2127–2131. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0014-9446">0014-9446</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/350631">350631</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Federation+Proceedings&rft.atitle=Ionic+mechanisms+of+pacemaker+activity+in+cardiac+Purkinje+fibers&rft.volume=37&rft.issue=8&rft.pages=2127-2131&rft.date=1978-06-01&rft_id=info%3Apmid%2F350631&rft.issn=0014-9446&rft.aulast=Tsien&rft.aufirst=R.+W.&rft.au=Carpenter%2C+D.+O.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-Vassalle1977-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-Vassalle1977_12-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFVassalle1977" class="citation journal cs1">Vassalle, M. (1977). <a rel="nofollow" class="external text" href="https://doi.org/10.1161%2F01.res.41.3.269">"The relationship among cardiac pacemakers: Overdrive suppression"</a>. <i><a href="/wiki/Circulation_Research" title="Circulation Research">Circulation Research</a></i>. <b>41</b> (3): 269–77. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1161%2F01.res.41.3.269">10.1161/01.res.41.3.269</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/330018">330018</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Circulation+Research&rft.atitle=The+relationship+among+cardiac+pacemakers%3A+Overdrive+suppression&rft.volume=41&rft.issue=3&rft.pages=269-77&rft.date=1977&rft_id=info%3Adoi%2F10.1161%2F01.res.41.3.269&rft_id=info%3Apmid%2F330018&rft.aulast=Vassalle&rft.aufirst=M.&rft_id=https%3A%2F%2Fdoi.org%2F10.1161%252F01.res.41.3.269&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFIrisawaBrownGiles1993" class="citation journal cs1">Irisawa, H; Brown, HF; Giles, W (1993). "Cardiac pacemaking in the sinoatrial node". <i>Physiol Rev</i>. <b>73</b> (1): 197–227. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1152%2Fphysrev.1993.73.1.197">10.1152/physrev.1993.73.1.197</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/8380502">8380502</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Physiol+Rev&rft.atitle=Cardiac+pacemaking+in+the+sinoatrial+node&rft.volume=73&rft.issue=1&rft.pages=197-227&rft.date=1993&rft_id=info%3Adoi%2F10.1152%2Fphysrev.1993.73.1.197&rft_id=info%3Apmid%2F8380502&rft.aulast=Irisawa&rft.aufirst=H&rft.au=Brown%2C+HF&rft.au=Giles%2C+W&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDiFrancesco2010" class="citation journal cs1">DiFrancesco, D (2010). <a rel="nofollow" class="external text" href="https://doi.org/10.1161%2Fcircresaha.109.208041">"The role of the funny current in pacemaker activity"</a>. <i>Circulation Research</i>. <b>106</b> (3): 434–46. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1161%2Fcircresaha.109.208041">10.1161/circresaha.109.208041</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/20167941">20167941</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Circulation+Research&rft.atitle=The+role+of+the+funny+current+in+pacemaker+activity&rft.volume=106&rft.issue=3&rft.pages=434-46&rft.date=2010&rft_id=info%3Adoi%2F10.1161%2Fcircresaha.109.208041&rft_id=info%3Apmid%2F20167941&rft.aulast=DiFrancesco&rft.aufirst=D&rft_id=https%3A%2F%2Fdoi.org%2F10.1161%252Fcircresaha.109.208041&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJoungChenLin2011" class="citation journal cs1">Joung, B.; Chen, P.; Lin, S. (2011). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3051220">"The role of the calcium and the voltage clocks in sinoatrial node dysfunction"</a>. <i>Yonsei Medical Journal</i>. <b>52</b> (2): 211–9. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.3349%2Fymj.2011.52.2.211">10.3349/ymj.2011.52.2.211</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3051220">3051220</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/21319337">21319337</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Yonsei+Medical+Journal&rft.atitle=The+role+of+the+calcium+and+the+voltage+clocks+in+sinoatrial+node+dysfunction&rft.volume=52&rft.issue=2&rft.pages=211-9&rft.date=2011&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC3051220%23id-name%3DPMC&rft_id=info%3Apmid%2F21319337&rft_id=info%3Adoi%2F10.3349%2Fymj.2011.52.2.211&rft.aulast=Joung&rft.aufirst=B.&rft.au=Chen%2C+P.&rft.au=Lin%2C+S.&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC3051220&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text">Verkerk, A., Borren, van, Peters, R., Broekhuis, E., Lam, K., Coronel, R., Bakker, de, Tan, H. and Wilders, R. (2007) 'Single cells isolated from human sinoatrial node: Action potentials and numerical reconstruction of pacemaker current', Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference., 2007, pp. 904–7.</span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFClarkMangoniLuegerCouette2004" class="citation journal cs1">Clark, R.B.; Mangoni, M.E.; Lueger, A.; Couette, B.; Nargeot, J.; Giles, W.R. (2004). "A rapidly activating delayed rectifier K+ current reg-ulates pacemaker activity in adult mouse sinoatrial node cells". <i>American Journal of Physiology. Heart and Circulatory Physiology</i>. <b>286</b> (5): 1757–1766. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1152%2Fajpheart.00753.2003">10.1152/ajpheart.00753.2003</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/14693686">14693686</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:476037">476037</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=American+Journal+of+Physiology.+Heart+and+Circulatory+Physiology&rft.atitle=A+rapidly+activating+delayed+rectifier+K%2B+current+reg-ulates+pacemaker+activity+in+adult+mouse+sinoatrial+node+cells&rft.volume=286&rft.issue=5&rft.pages=1757-1766&rft.date=2004&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A476037%23id-name%3DS2CID&rft_id=info%3Apmid%2F14693686&rft_id=info%3Adoi%2F10.1152%2Fajpheart.00753.2003&rft.aulast=Clark&rft.aufirst=R.B.&rft.au=Mangoni%2C+M.E.&rft.au=Lueger%2C+A.&rft.au=Couette%2C+B.&rft.au=Nargeot%2C+J.&rft.au=Giles%2C+W.R.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGordanGwathmeyXie2015" class="citation journal cs1">Gordan, R.; Gwathmey, J.K.; Xie, L.-H. (2015). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4404375">"Autonomic and endocrine control of cardiovascular function"</a>. <i>World Journal of Cardiology</i>. <b>7</b> (4): 204–14. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.4330%2Fwjc.v7.i4.204">10.4330/wjc.v7.i4.204</a></span>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4404375">4404375</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/25914789">25914789</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=World+Journal+of+Cardiology&rft.atitle=Autonomic+and+endocrine+control+of+cardiovascular+function&rft.volume=7&rft.issue=4&rft.pages=204-14&rft.date=2015&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC4404375%23id-name%3DPMC&rft_id=info%3Apmid%2F25914789&rft_id=info%3Adoi%2F10.4330%2Fwjc.v7.i4.204&rft.aulast=Gordan&rft.aufirst=R.&rft.au=Gwathmey%2C+J.K.&rft.au=Xie%2C+L.-H.&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC4404375&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text">Larsson, P.H. (2010) 'How is the heart rate regulated in the sinoatrial node? Another piece to the puzzle', 136(3).</span> </li> <li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text">Osterrieder W., Noma A., Trautwein W. (1980) On the kinetics of the potassium current activated by acetylcholine in the SA node of the rabbit heart. Pflügers Arch. 386:101–109.</span> </li> <li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.mountsinai.org/patient-care/health-library/diseases-and-conditions/sick-sinus-syndrome">Sinus node dysfunction</a> <a href="/wiki/Mount_Sinai_Hospital,_New_York" class="mw-redirect" title="Mount Sinai Hospital, New York">Mount Sinai Hospital, New York</a></span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text"><i><a rel="nofollow" class="external text" href="https://emedicine.medscape.com/article/155146-overview">Junctional Rhythm</a></i> at <a href="/wiki/EMedicine" title="EMedicine">eMedicine</a></span> </li> <li id="cite_note-heart-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-heart_23-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSilvermanHollman2007" class="citation journal cs1">Silverman, M.E.; Hollman, A. (1 October 2007). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2000948">"Discovery of the sinus node by Keith and Flack: on the centennial of their 1907 publication"</a>. <i><a href="/wiki/Heart_(journal)" title="Heart (journal)">Heart</a></i>. <b>93</b> (10): 1184–1187. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1136%2Fhrt.2006.105049">10.1136/hrt.2006.105049</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2000948">2000948</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/17890694">17890694</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Heart&rft.atitle=Discovery+of+the+sinus+node+by+Keith+and+Flack%3A+on+the+centennial+of+their+1907+publication&rft.volume=93&rft.issue=10&rft.pages=1184-1187&rft.date=2007-10-01&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC2000948%23id-name%3DPMC&rft_id=info%3Apmid%2F17890694&rft_id=info%3Adoi%2F10.1136%2Fhrt.2006.105049&rft.aulast=Silverman&rft.aufirst=M.E.&rft.au=Hollman%2C+A.&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC2000948&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> <li id="cite_note-pmid17556667-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-pmid17556667_24-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBoyett_MR,_Dobrzynski_H2007" class="citation journal cs1">Boyett MR, Dobrzynski H (June 2007). "The sinoatrial node is still setting the pace 100 years after its discovery". <i>Circ. Res</i>. <b>100</b> (11): 1543–5. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1161%2FCIRCRESAHA.107.101101">10.1161/CIRCRESAHA.107.101101</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/17556667">17556667</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:17882001">17882001</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Circ.+Res.&rft.atitle=The+sinoatrial+node+is+still+setting+the+pace+100+years+after+its+discovery&rft.volume=100&rft.issue=11&rft.pages=1543-5&rft.date=2007-06&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A17882001%23id-name%3DS2CID&rft_id=info%3Apmid%2F17556667&rft_id=info%3Adoi%2F10.1161%2FCIRCRESAHA.107.101101&rft.au=Boyett+MR%2C+Dobrzynski+H&rfr_id=info%3Asid%2Fen.wikipedia.org%3ASinoatrial+node" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Sinoatrial_node&action=edit&section=14" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20100101010101/http://ect.downstate.edu/courseware/haonline/figs/l20/200601.htm">Anatomy figure: 20:06-01</a> at Human Anatomy Online, SUNY Downstate Medical Center - "The conduction system of the heart."</li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20070313214609/http://user.gru.net/clawrence/vccl/chpt2/adlt46.gif">Diagram at gru.net</a></li> <li><a rel="nofollow" class="external text" href="http://www.wesnorman.com/thoraxlesson4.htm">thoraxlesson4</a> at The Anatomy Lesson by Wesley Norman (Georgetown University) (<i><a rel="nofollow" class="external text" href="http://www.wesnorman.com/Images/thoraxheartinternalner.jpg">thoraxheartinternalner</a></i>)</li> <li><a rel="nofollow" class="external free" href="https://web.archive.org/web/20070929080346/http://www.healthyheart.nhs.uk/heart_works/heart03.shtml">https://web.archive.org/web/20070929080346/http://www.healthyheart.nhs.uk/heart_works/heart03.shtml</a></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist dd:last-child::after,.mw-parser-output .hlist dt:last-child::after,.mw-parser-output .hlist li:last-child::after{content:none}.mw-parser-output .hlist dd dd:first-child::before,.mw-parser-output .hlist dd dt:first-child::before,.mw-parser-output .hlist dd li:first-child::before,.mw-parser-output .hlist dt dd:first-child::before,.mw-parser-output .hlist dt dt:first-child::before,.mw-parser-output .hlist dt li:first-child::before,.mw-parser-output .hlist li dd:first-child::before,.mw-parser-output .hlist li dt:first-child::before,.mw-parser-output .hlist li li:first-child::before{content:" (";font-weight:normal}.mw-parser-output .hlist dd dd:last-child::after,.mw-parser-output .hlist dd dt:last-child::after,.mw-parser-output .hlist dd li:last-child::after,.mw-parser-output .hlist dt dd:last-child::after,.mw-parser-output .hlist dt dt:last-child::after,.mw-parser-output .hlist dt li:last-child::after,.mw-parser-output .hlist li dd:last-child::after,.mw-parser-output .hlist li dt:last-child::after,.mw-parser-output .hlist li li:last-child::after{content:")";font-weight:normal}.mw-parser-output .hlist ol{counter-reset:listitem}.mw-parser-output .hlist ol>li{counter-increment:listitem}.mw-parser-output .hlist ol>li::before{content:" "counter(listitem)"\a0 "}.mw-parser-output .hlist dd ol>li:first-child::before,.mw-parser-output .hlist dt ol>li:first-child::before,.mw-parser-output .hlist li ol>li:first-child::before{content:" ("counter(listitem)"\a0 "}</style><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output .navbox-list-with-group{text-align:left;border-left-width:2px;border-left-style:solid}.mw-parser-output tr+tr>.navbox-abovebelow,.mw-parser-output tr+tr>.navbox-group,.mw-parser-output tr+tr>.navbox-image,.mw-parser-output tr+tr>.navbox-list{border-top:2px solid #fdfdfd}.mw-parser-output .navbox-title{background-color:#ccf}.mw-parser-output .navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}</style></div><div role="navigation" class="navbox" aria-labelledby="Anatomy_of_the_heart" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapsed navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Heart_anatomy" title="Template:Heart anatomy"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Heart_anatomy" title="Template talk:Heart anatomy"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Heart_anatomy" title="Special:EditPage/Template:Heart anatomy"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Anatomy_of_the_heart" style="font-size:114%;margin:0 4em">Anatomy of the <a href="/wiki/Heart" title="Heart">heart</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">General</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Surface</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Base_of_the_heart" class="mw-redirect" title="Base of the heart">base</a></li> <li><a href="/wiki/Apex_of_the_heart" class="mw-redirect" title="Apex of the heart">apex</a></li> <li><a href="/wiki/Sulcus_(morphology)" title="Sulcus (morphology)">sulci</a> <ul><li><a href="/wiki/Coronary_sulcus" title="Coronary sulcus">coronary</a></li> <li><a href="/wiki/Interatrial_sulcus" title="Interatrial sulcus">interatrial</a></li> <li><a href="/wiki/Anterior_interventricular_sulcus" title="Anterior interventricular sulcus">anterior interventricular</a></li> <li><a href="/wiki/Posterior_interventricular_sulcus" title="Posterior interventricular sulcus">posterior interventricular</a></li></ul></li> <li>borders <ul><li><a href="/wiki/Right_border_of_heart" title="Right border of heart">right</a></li> <li><a href="/wiki/Left_margin_of_heart" class="mw-redirect" title="Left margin of heart">left</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Internal</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><td colspan="2" class="navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Atrium_(heart)" title="Atrium (heart)">atria</a> <ul><li><a href="/wiki/Interatrial_septum" title="Interatrial septum">interatrial septum</a></li> <li><a href="/wiki/Pectinate_muscles" title="Pectinate muscles">pectinate muscles</a></li> <li><a href="/wiki/Terminal_sulcus_(heart)" title="Terminal sulcus (heart)">terminal sulcus</a></li></ul></li> <li><a href="/wiki/Ventricle_(heart)" title="Ventricle (heart)">ventricles</a> <ul><li><a href="/wiki/Interventricular_septum" title="Interventricular septum">interventricular septum</a></li> <li><a href="/wiki/Trabeculae_carneae" title="Trabeculae carneae">trabeculae carneae</a></li> <li><a href="/wiki/Chordae_tendineae" title="Chordae tendineae">chordae tendineae</a></li> <li><a href="/wiki/Papillary_muscle" title="Papillary muscle">papillary muscle</a></li></ul></li> <li><a href="/wiki/Heart_valve" title="Heart valve">valves</a></li> <li><a href="/wiki/Cusps_of_heart_valves" class="mw-redirect" title="Cusps of heart valves">cusps</a></li> <li><a href="/wiki/Atrioventricular_septum" title="Atrioventricular septum">atrioventricular septum</a></li></ul> </div></td></tr><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cardiac_skeleton" title="Cardiac skeleton">cardiac skeleton</a></li> <li><a href="/wiki/Intervenous_tubercle" title="Intervenous tubercle">intervenous tubercle</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Chambers</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Right_heart" class="mw-redirect" title="Right heart">Right heart</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i>(<a href="/wiki/Venae_cavae" title="Venae cavae">venae cavae</a>, <a href="/wiki/Coronary_sinus" title="Coronary sinus">coronary sinus</a>)</i> → <a href="/wiki/Right_atrium" class="mw-redirect" title="Right atrium">right atrium</a> (<a href="/wiki/Right_atrial_appendage" class="mw-redirect" title="Right atrial appendage">atrial appendage</a>, <a href="/wiki/Fossa_ovalis_(heart)" title="Fossa ovalis (heart)">fossa ovalis</a>, <a href="/wiki/Limbus_of_fossa_ovalis" class="mw-redirect" title="Limbus of fossa ovalis">limbus of fossa ovalis</a>, <a href="/wiki/Crista_terminalis" title="Crista terminalis">crista terminalis</a>, <a href="/wiki/Valve_of_inferior_vena_cava" title="Valve of inferior vena cava">valve of inferior vena cava</a>, <a href="/wiki/Valve_of_coronary_sinus" title="Valve of coronary sinus">valve of coronary sinus</a>) → <a href="/wiki/Tricuspid_valve" title="Tricuspid valve">tricuspid valve</a> → <a href="/wiki/Right_ventricle" class="mw-redirect" title="Right ventricle">right ventricle</a> (<a href="/wiki/Infundibulum_(heart)" title="Infundibulum (heart)">infundibulum</a>, <a href="/wiki/Moderator_band_(heart)" class="mw-redirect" title="Moderator band (heart)">moderator band/septomarginal trabecula</a>, <a href="/wiki/Crista_supraventricularis" title="Crista supraventricularis">crista supraventricularis</a>), → <a href="/wiki/Pulmonary_valve" title="Pulmonary valve">pulmonary valve</a> → <i>(<a href="/wiki/Pulmonary_artery" title="Pulmonary artery">pulmonary artery</a> and <a href="/wiki/Pulmonary_circulation" title="Pulmonary circulation">pulmonary circulation</a>)</i></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Left_heart" class="mw-redirect" title="Left heart">Left heart</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i>(<a href="/wiki/Pulmonary_vein" title="Pulmonary vein">pulmonary veins</a>)</i> → <a href="/wiki/Left_atrium" class="mw-redirect" title="Left atrium">left atrium</a> (<a href="/wiki/Left_atrial_appendage" class="mw-redirect" title="Left atrial appendage">atrial appendage</a>) → <a href="/wiki/Mitral_valve" title="Mitral valve">mitral valve</a> → <a href="/wiki/Left_ventricle" class="mw-redirect" title="Left ventricle">left ventricle</a> → <a href="/wiki/Aortic_valve" title="Aortic valve">aortic valve</a> (<a href="/wiki/Aortic_sinus" title="Aortic sinus">aortic sinus</a>) → <i>(<a href="/wiki/Aorta" title="Aorta">aorta</a> and <a href="/wiki/Systemic_circulation" class="mw-redirect" title="Systemic circulation">systemic circulation</a>)</i></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Layers</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Endocardium" title="Endocardium">Endocardium</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Heart_valve" title="Heart valve">heart valves</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Cardiac_muscle" title="Cardiac muscle">Myocardium</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Electrical_conduction_system_of_the_heart" class="mw-redirect" title="Electrical conduction system of the heart">Conduction system</a> <ul><li><a href="/wiki/Cardiac_pacemaker" title="Cardiac pacemaker">cardiac pacemaker</a></li> <li><a class="mw-selflink selflink">SA node</a></li> <li><a href="/wiki/Bachmann%27s_bundle" title="Bachmann's bundle">Bachmann's bundle</a></li> <li><a href="/wiki/Atrioventricular_node" title="Atrioventricular node">AV node</a></li> <li><a href="/wiki/Bundle_of_His" title="Bundle of His">bundle of His</a></li> <li><a href="/wiki/Bundle_branches" title="Bundle branches">bundle branches</a></li> <li><a href="/wiki/Purkinje_fibers" title="Purkinje fibers">Purkinje fibers</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Pericardium" title="Pericardium">Pericardial cavity</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Pericardial_sinus" title="Pericardial sinus">pericardial sinus</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Pericardium" title="Pericardium">Pericardium</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Fibrous_pericardium" class="mw-redirect" title="Fibrous pericardium">fibrous pericardium</a> <ul><li><a href="/wiki/Sternopericardial_ligaments" title="Sternopericardial ligaments">sternopericardial ligaments</a></li></ul></li> <li><a href="/wiki/Serous_pericardium" class="mw-redirect" title="Serous pericardium">serous pericardium</a> <ul><li><a href="/wiki/Epicardium" class="mw-redirect" title="Epicardium">epicardium/visceral layer</a></li></ul></li> <li><a href="/wiki/Fold_of_left_vena_cava" title="Fold of left vena cava">fold of left vena cava</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Blood supply</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Circulatory_system" title="Circulatory system">Circulatory system</a></li> <li><a href="/wiki/Coronary_circulation" title="Coronary circulation">Coronary circulation</a></li> <li><a href="/wiki/Coronary_arteries" title="Coronary arteries">Coronary arteries</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox authority-control" aria-label="Navbox" style="padding:3px"><table class="nowraplinks hlist navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Help:Authority_control" title="Help:Authority control">Authority control databases</a> <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q286020#identifiers" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><a class="external text" href="http://tools.wmflabs.org/wikidata-externalid-url/?p=1323&url_prefix=https:%2F%2Fwww.unifr.ch%2Fifaa%2FPublic%2FEntryPage%2FTA98%20Tree%2FEntity%20TA98%20EN%2F&url_suffix=%20Entity%20TA98%20EN.htm&id=A12.1.06.003">Terminologia Anatomica</a></span></li></ul></div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1&useformat=desktop" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Sinoatrial_node&oldid=1251688092">https://en.wikipedia.org/w/index.php?title=Sinoatrial_node&oldid=1251688092</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Category</a>: <ul><li><a href="/wiki/Category:Cardiac_anatomy" title="Category:Cardiac anatomy">Cardiac anatomy</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:CS1_maint:_location_missing_publisher" title="Category:CS1 maint: location missing publisher">CS1 maint: location missing publisher</a></li><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_matches_Wikidata" title="Category:Short description matches Wikidata">Short description matches Wikidata</a></li><li><a href="/wiki/Category:Use_dmy_dates_from_April_2017" title="Category:Use dmy dates from April 2017">Use dmy dates from April 2017</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 17 October 2024, at 14:22<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. By using this site, you agree to the <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use" class="extiw" title="foundation:Special:MyLanguage/Policy:Terms of Use">Terms of Use</a> and <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy" class="extiw" title="foundation:Special:MyLanguage/Policy:Privacy policy">Privacy Policy</a>. Wikipedia® is a registered trademark of the <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, a non-profit organization.</li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:About">About Wikipedia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:General_disclaimer">Disclaimers</a></li> <li id="footer-places-contact"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us">Contact Wikipedia</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code of Conduct</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Developers</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/en.wikipedia.org">Statistics</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie statement</a></li> <li id="footer-places-mobileview"><a href="//en.m.wikipedia.org/w/index.php?title=Sinoatrial_node&mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">Mobile view</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/static/images/footer/wikimedia-button.svg" width="84" height="29" alt="Wikimedia Foundation" loading="lazy"></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/w/resources/assets/poweredby_mediawiki.svg" alt="Powered by MediaWiki" width="88" height="31" loading="lazy"></a></li> </ul> </footer> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-7c4dcdbb87-fhbcn","wgBackendResponseTime":137,"wgPageParseReport":{"limitreport":{"cputime":"0.585","walltime":"0.783","ppvisitednodes":{"value":2647,"limit":1000000},"postexpandincludesize":{"value":91361,"limit":2097152},"templateargumentsize":{"value":1603,"limit":2097152},"expansiondepth":{"value":12,"limit":100},"expensivefunctioncount":{"value":3,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":97372,"limit":5000000},"entityaccesscount":{"value":1,"limit":400},"timingprofile":["100.00% 691.874 1 -total"," 37.75% 261.196 1 Template:Reflist"," 22.86% 158.147 1 Template:Infobox_anatomy"," 22.08% 152.780 1 Template:Infobox"," 18.70% 129.350 17 Template:Cite_journal"," 15.14% 104.738 5 Template:Navbox"," 14.40% 99.664 1 Template:Heart_anatomy"," 12.52% 86.589 1 Template:Cite_book"," 10.98% 75.977 1 Template:Short_description"," 5.71% 39.534 2 Template:Pagetype"]},"scribunto":{"limitreport-timeusage":{"value":"0.361","limit":"10.000"},"limitreport-memusage":{"value":6835481,"limit":52428800}},"cachereport":{"origin":"mw-web.codfw.main-5857dfdcd6-fwcbr","timestamp":"20241203065443","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"Sinoatrial node","url":"https:\/\/en.wikipedia.org\/wiki\/Sinoatrial_node","sameAs":"http:\/\/www.wikidata.org\/entity\/Q286020","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q286020","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2004-04-15T17:25:58Z","dateModified":"2024-10-17T14:22:40Z","image":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/e\/e6\/Reizleitungssystem_1.png","headline":"group of cells located in the wall of the right atrium of the heart"}</script> </body> </html>