Definition

Noun A small, nipple-shaped muscle located in the ventricles of the heart. These muscles are attached to the cusps of the atrioventricular valves (the mitral and tricuspid valves) via tendinous cords called chordae tendineae.

Usage

The term "papillary muscle" is used in anatomical, medical, and physiological contexts to describe these specific cardiac structures. It is typically used in the singular when referring to one such muscle or in the plural ("papillary muscles") when referring to the group.

Examples

• The papillary muscle is an integral part of the heart's valve apparatus.
• During a heart attack, ischemia can damage the papillary muscles.
• The primary function of the papillary muscles is to stabilize the atrioventricular valves.
• Rupture of a papillary muscle is a serious complication of myocardial infarction.

Advanced Usage

• Papillary muscle dysfunction: A condition where the muscle is unable to contract properly, often leading to valve leakage (regurgitation).
• Anterolateral papillary muscle: A specific papillary muscle in the left ventricle, typically supplied by the left anterior descending coronary artery and the circumflex artery.
• Posteromedial papillary muscle: A specific papillary muscle in the left ventricle, typically supplied by the right coronary artery.

Variants and Related Words

• Papillary (adjective): Of or relating to or resembling a papilla (a small nipple-shaped projection). Example: .
• Chordae tendineae (noun): The tendon-like cords that connect the papillary muscles to the valve cusps.
• Atrioventricular valve (noun): The valve (mitral or tricuspid) to which the papillary muscles are connected.

Synonyms

• There are no direct common synonyms for this specific anatomical term. Descriptive phrases like "cardiac valve muscle" or "ventricular valve muscle" may be used in non-technical explanations but are not standard medical terminology.

Related Phrases

• Papillary muscle contraction: The tightening of the muscle during the cardiac cycle.
• Papillary muscle rupture: A tear or break in the muscle, often due to infarction.

Notes on Meaning

The definition centers on the muscle's anatomical structure (nipple-shaped, located in ventricles) and its functional role in the heart. Its sole purpose is to tense the chordae tendineae during ventricular contraction (systole), preventing the valve leaflets from prolapsing backward into the atria. This ensures blood flows forward into the arteries and does not regurgitate backward.

Noun

1. any of several muscles associated with the atrioventricular valves
   • the papillary muscles contract during systole to prevent regurgitation of blood into the atria