Viscera (heart, lungs, liver, gastrointestinal tract)
Posteromedial (inferior) papillary muscle of left ventricle
Musculus papillaris inferior (posterior) ventriculi sinistri
- Origin
- Inferoposterior wall of the left ventricle
- Insertion
- Chordae tendineae inserting into both the anterior and posterior cusps of the mitral valve
- Function
- Prevents mitral valve leaflet prolapse into the left atrium during ventricular systole
- Innervation
- Cardiac plexus; left bundle branch posterior fascicle
- Movement & chain
- Synchronous systolic contraction under single blood supply from the posterior descending artery (PDA)
- Palpation
- Assessed by echocardiography
- Clinical
- Vulnerable to ischemic rupture in inferior myocardial infarction due to single vascular supply (PDA), precipitating catastrophic acute mitral regurgitation and cardiogenic shock.
- Segmental innervation
- T1-T4 spinal segments
- In clinical practice
- Urgent recognition of new systolic murmurs in acute coronary syndrome, immediate stabilization with inotropes, vasodilators, mechanical support, and emergency surgical consultation
- Region in the model
- Viscera (heart, lungs, liver, gastrointestinal tract)