Musculi pectinati
Encyclopedia
In the right atrium
, behind the crest, the internal surface is smooth. While in front of it, the muscular fibers of the wall are raised into parallel ridges resembling the teeth of a comb, and hence named the musculi pectinati (pectinate muscles).
In the left atrium
, the musculi pectinati, fewer and smaller than in the right auricula, are confined to the inner surface of the auricula. This is due to the embryological origin of the auricles, which are the true atria. Some sources cite that the musculi pectinati are useful in increasing the power of contraction without increasing heart mass substantially.
Right atrium
The right atrium is one of four chambers in the hearts of mammals and archosaurs...
, behind the crest, the internal surface is smooth. While in front of it, the muscular fibers of the wall are raised into parallel ridges resembling the teeth of a comb, and hence named the musculi pectinati (pectinate muscles).
In the left atrium
Left atrium
The left atrium is one of the four chambers in the human heart. It receives oxygenated blood from the pulmonary veins, and pumps it into the left ventricle, via the mitral valve.-Foramen ovale:...
, the musculi pectinati, fewer and smaller than in the right auricula, are confined to the inner surface of the auricula. This is due to the embryological origin of the auricles, which are the true atria. Some sources cite that the musculi pectinati are useful in increasing the power of contraction without increasing heart mass substantially.