- Atrioventricular node
Infobox Anatomy
Name = PAGENAME
Latin = nodus atrioventricularis
GraySubject =
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Caption = AV node visible near bend of red line.
Caption2 = Heart; conduction system
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System =
Artery =atrioventricular nodal branch
Vein =
Nerve =
Lymph =
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DorlandsPre = n_09
DorlandsSuf = 12576113
The atrioventricular node (abbreviated AV node) is an area of specialized tissue between the atria and the ventricles of theheart , specifically in the posteroinferior region of the interatrial septum near the opening of the coronary sinus, which conducts the normal electrical impulse from the atria to the ventricles.The AV node may also be (rarely) referred to as the "Aschoff-Tawara node". [WhoNamedIt|synd|454]
Function
The AV node receives two inputs from the atria: posteriorly via the
crista terminalis , and anteriorly via the interatrialseptum . [ACC/AHA/ESC Guidelines for the Management of Patients with Atrial Fibrillation - Executive Summary ( [http://www.acc.org/clinical/guidelines/atrial_fib/exec_summ/exec_afindex.htm Full text] )]An important property that is unique to the AV node is "decremental conduction", in which the more frequently the node is stimulated, the slower it conducts. This is the property of the AV node that prevents rapid conduction to the ventricle in cases of rapid atrial rhythms, such as
atrial fibrillation oratrial flutter .The atrioventricular node delays impulses for a while (aprox. 0.16s) before allowing impulses through to the His-Purkinje conduction system, which spreads impulses to the ventricular walls. The reason it is important to delay the cardiac impulse is to ensure that the atria have ejected their blood into the ventricles before the ventricles contract. [Campbell, N., & Reece, J. (2002). Biology. 6th ed. San Francisco: Benjamin Cummings.]
The AV node is located between the right atrium and right ventricle. It slows the signals and allows the ventricles to fill before it moves on.
Blood supply
The blood supply of the AV node is from the
posterior interventricular artery . When the RCA supplies the posterior descending artery and thus the AV node, the coronary system is said to be "right dominant," and when the posterior descending artery is supplied by the LCX, the system is "left dominant."ee also
*
Electrical conduction system of the heart
*Sinoatrial node (SA node)References
External links
* - "The conduction system of the heart."
* (NormanAnatomyFig|thoraxheartinternalner)
* http://www.healthyheart.nhs.uk/heart_works/heart03.shtml
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