The trabeculae carneae are rounded or irregular muscular columns which project from the inner surface of the right

Right ventricle

The right ventricle is one of four chambers in the human heart. It receives deoxygenated blood from the right atrium via the tricuspid valve, and pumps it into the pulmonary artery via the pulmonary valve and pulmonary trunk....

 and left

Left ventricle

The left ventricle is one of four chambers in the human heart. It receives oxygenated blood from the left atrium via the mitral valve, and pumps it into the aorta via the aortic valve.-Shape:...

 ventricles

Ventricle (heart)

In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...

 of the heart. They should not be confused with the pectinate muscles, which are present in the right atrium and right and left auricle only.

Types

They are of three kinds:

• some are attached along their entire length on one side and merely form prominent ridges,
• others are fixed at their extremities but free in the middle,
• while a third set, the papillary muscles are continuous by their bases with the wall of the ventricle, while their apices give origin to the chordæ tendineæ which pass to be attached to the segments of both the bicuspid valve (mitral valve, or left atrioventricular valve) and the tricuspid valve
  Tricuspid valve
  The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian heart, between the right atrium and the right ventricle. The normal tricuspid valve usually has three leaflets and three papillary muscles. They are connected to the papillary muscles by the chordae...
  
   (right atrioventricular valve).

Function

The purpose of the trabeculae carneae is most likely to prevent suction that would occur with a flat surfaced membrane and thus impair the heart's ability to pump efficiently.

The trabeculae carneae also serve a similar function to papillary muscles in that their contraction pulls on the chordae tendineae, preventing inversion of the mitral (bicuspid) and tricuspid valves, that is, their bulging towards the atrial chambers, which would lead to subsequent leakage of the blood into the atria. So by the action of papillary muscles on the atrioventricular valves, backflow of the blood from the ventricles into the atria is prevented.

External links

( - "TC" on diagram)

• Diagram at University of Edinburgh
  University of Edinburgh
  The University of Edinburgh, founded in 1583, is a public research university located in Edinburgh, the capital of Scotland, and a UNESCO World Heritage Site. The university is deeply embedded in the fabric of the city, with many of the buildings in the historic Old Town belonging to the university...
  
  -- fourth and fifth diagrams from top