Papillary muscle

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Papillary muscle
Right ventricle.
V.S. Ventricular septum.
Details
Identifiers
Latinmusculus papillaris
MeSHD010210
TA98A12.1.00.022
TA24043, 4066
FMA12154
Anatomical terms of muscle]

The papillary muscles are muscles located in the ventricles of the heart. They attach to the cusps of the

atrioventricular valves (also known as the mitral and tricuspid valves) via the chordae tendineae and contract to prevent inversion or prolapse of these valves on systole (or ventricular contraction).[1]

Structure

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 anterolateral and posteromedial papillary muscles of the left ventricle attach via chordae tendineae to the mitral valve.[2]

Blood supply

The mitral valve papillary muscles in the left ventricle are called the anterolateral and posteromedial muscles.[3]

  • Anterolateral muscle blood supply:
    obtuse marginal branch
    (LCX)
  • Posteromedial muscle blood supply:
    posterior interventricular artery
    (RCA)

The posteromedial muscle ruptures more frequently because it only has one source of blood supply, hence RCA occlusion can cause papillary muscle rupture.[3]

Function

The papillary muscles of both the right and left ventricles begin to contract shortly before

ventricular systole and maintain tension throughout.[1] 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]

Clinical significance

Papillary muscle rupture can be caused by a

myocardial infarction, and dysfunction can be caused by ischemia. Rarely, blunt chest trauma can be the cause of papillary muscle rupture, resulting from the sudden deceleration or compression of the heart.[4] Complications may lead to worsening of mitral regurgitation.[5]

Additional images

  • Opened chambers of the heart displaying papillary muscles and chordae tendineae
    Opened chambers of the heart displaying papillary muscles and chordae tendineae
  • Papillary muscle infarction
    Papillary muscle infarction
  • Papillary muscles and chordae tendineae
    Papillary muscles and chordae tendineae
  • Papillary muscles and chordae tendineae
    Papillary muscles and chordae tendineae
  • Papillary muscles. Deep dissection.
    Papillary muscles. Deep dissection.

See also

References

  1. ^
    ISBN 978-0-7817-6274-8
    .
  2. ^ Netter's Atlas of Human Anatomy, plates 216B and 217A
  3. ^
    PMID 21382906
    .
  4. doi:10.1016/S0003-4975(00)02498-X
    .
  5. ISBN 978-0-7817-7153-5
    .

External links
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