Corpus: Papillary muscle

In veterinary medicine, papillary muscles or papillary muscles are conical protrusions of the heart muscles into the lumen of the ventricles. These are connected to the atrioventricular valves via chordae tendinae.

The chordae tendinae have their origin at the papillary muscles and from there they extend to the respective leaflet valves. Each papillary muscle sends tendinous filaments to two leaflet valves.

There are three papillary muscles in the right ventricle:

• Musculus papillaris magnus: parietal in ungulates, more septal in carnivores
• Musculus papillaris subarteriosus: located ventral to the opening of the pulmonary artery
• Musculi papillares parvi: group of muscles located caudal to the cardiac septum

Two papillary muscles can be differentiated in the left ventricle:

• Musculus papillaris subauricularis: wall-mounted, ventral to the left auricle
• Musculus papillaris subatrialis: wall-mounted, ventral to the left atrium

Contraction of the papillary muscles causes tension in the chordae tendinae, which prevents the valve leaflets from penetrating into the atrium.

• Salomon FV, Geyer H, Uwe G. 2008. anatomy for veterinary medicine. 2nd, updated and expanded edition. Stuttgart: Enke Verlag in MVS Medizinverlage Stuttgart GmbH & Co. KG. ISBN: 978-3-8304-1075-1
• Nickel R, Schummer A, Seiferle E. 2004. Textbook of Domestic Animal Anatomy, Volume III: Circulatory System, Skin and Skin Organs. 4th, unchanged edition. Stuttgart: Parey in MSV Medizinverlage Stuttgart GmbH & Co. KG. ISBN: 978-3-8304-4164-9