Definition

Noun: A small, specialized mass of cardiac muscle tissue located in the lower part of the wall (septum) that separates the right atrium and right ventricle of the heart. Its primary function is to receive electrical impulses from the sinoatrial node (the heart's natural pacemaker), introduce a slight delay in their transmission, and then relay them to the atrioventricular bundle (Bundle of His), which conducts the impulses to the ventricles. This delay is crucial for allowing the atria to contract and fill the ventricles with blood before the ventricles themselves contract.

Usage

The term "atrioventricular node" is used in medical, anatomical, and physiological contexts to describe a specific component of the heart's electrical conduction system. - It is often abbreviated as AV node. - It is typically discussed in relation to heart rhythm, cardiac electrophysiology, and conditions like heart block.

Examples

• In Anatomy:
  • The atrioventricular node is situated near the opening of the coronary sinus in the interatrial septum.
• In Physiology:
  • A properly functioning atrioventricular node ensures coordinated contraction between the atria and ventricles.
• In Medical Context:
  • Damage to the atrioventricular node can result in a condition called heart block, where the electrical signals from the atria are delayed or blocked from reaching the ventricles.

Advanced Usage

• "AV nodal reentrant tachycardia (AVNRT)": A common type of supraventricular tachycardia (rapid heart rate) caused by a reentrant circuit within or near the atrioventricular node.
  • The patient's palpitations were diagnosed as AV nodal reentrant tachycardia.
• "AV nodal blocking agents": A class of medications (like beta-blockers or calcium channel blockers) that slow conduction through the AV node to control heart rate.
  • Adenosine is an AV nodal blocking agent used to terminate certain tachycardias.

Variants and Related Words

• AV node (n): The standard abbreviation for atrioventricular node.
  • The ECG showed a problem with the AV node.
• Atrioventricular (AV) (adj): Pertaining to both the atria and the ventricles of the heart.
  • The atrioventricular valves are the mitral and tricuspid valves.
• Sinoatrial node (SA node) (n): The heart's primary pacemaker, which initiates the electrical impulse that the AV node later receives.
  • The sinoatrial node generates the normal heart rhythm.

Synonyms

• AV junction: A less common but sometimes used term referring to the general area of the AV node and the nearby tissue.
• Aschoff-Tawara node: A historical eponym for the atrioventricular node, named after the pathologists who described it.

Related Phrases and Concepts

• Atrioventricular bundle (Bundle of His): The bundle of specialized fibers that conducts impulses from the AV node to the ventricles.
  • The impulse travels from the AV node to the atrioventricular bundle.
• Heart's conduction system: The entire network of specialized cardiac cells that generates and conducts electrical impulses, including the SA node, AV node, and Bundle of His.
  • An arrhythmia is a disorder of the heart's conduction system.

Noun

1. a node of specialized heart muscle located in the septal wall of the right atrium; receives impulses from the sinoatrial node and transmits them to atrioventricular bundle