Papillary muscle

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Papillary muscle
Papillary muscles.png
Interior of right side of heart. Papillary muscles labeled in purple.
Gray1218.png
Diagram showing relations of opened heart to front of thoracic wall.

Ant. Anterior segment of tricuspid valve.
A O. Aorta.
A.P. Anterior papillary muscle.
In. Brachiocephalic artery (Innominate).
L.C.C. Left common carotid artery.
L.S. Left subclavian artery.
L.V. Left ventricle.
P.A. Pulmonary artery.
R.A. Right atrium.
R.V. Right ventricle.
V.S. Ventricular septum.
Details
Latin musculus papillaris
Identifiers
Gray's p.532
Anatomical terminology

In anatomy, the papillary muscles are muscles located in the ventricles of the heart. They attach to the cusps of the atrioventricular valves (a.k.a. the mitral and tricuspid valves) via the chordae tendineae and contract to prevent inversion or prolapse of these valves.[1][2]

Action[edit]

There are five total papillary muscles in the heart, three in the right ventricle and two in the left. The anterior, posterior, and septal papillary muscles of the right ventricle each attach via chordae tendineae to the tricuspid valve. The anterior and posterior papillary muscles of the left ventricle attach via chordae tendineae to the mitral valve.[3]

The papillary muscles of both the right[1] and the left[2] ventricles begin to contract shortly before ventricular systole and maintain tension throughout. This prevents regurgitation—backward flow of ventricular blood into the atrial cavities—by bracing the atrioventricular valves against prolapse—being forced back into the atria by the high pressure in the ventricles.[1]

Rupture[edit]

Papillary muscle rupture, as can be caused by a myocardial infarct, and dysfunction, as can be caused by ischemia, can both lead to the complication of mitral valve prolapse.[4]

Additional images[edit]

See also[edit]

References[edit]

  1. ^ a b c Moore, K.L., & Agur, A.M. (2007). Essential Clinical Anatomy: Third Edition. Baltimore: Lippincott Williams & Wilkins. 92. ISBN 978-0-7817-6274-8
  2. ^ a b Moore, K.L., & Agur, A.M. (2007). Essential Clinical Anatomy: Third Edition. Baltimore: Lippincott Williams & Wilkins. 94. ISBN 978-0-7817-6274-8
  3. ^ Netter's Atlas of Human Anatomy, plates 216B and 217A
  4. ^ Page 40 in:Elizabeth D Agabegi; Agabegi, Steven S. (2008). Step-Up to Medicine (Step-Up Series). Hagerstwon, MD: Lippincott Williams & Wilkins. ISBN 0-7817-7153-6. 

External links[edit]