Musculi pectinati

Musculi pectinati
Section of the heart showing the ventricular septum. (Musculi pectinati labeled at center left.)
Latin	musculi pectinati atrii dextri, musculi pectinati atrii sinistri
Gray's	subject #138 529

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.

External links

• -2066743237 at GPnotebook
• MedEd at Loyola grossanatomy/dissector/labs/thorax/heart/he3_1b.htm
• SUNY Labs 20:13-0104
• Atlas of anatomy at UMich ht_rt_atrium - "Right atrium, internal structure, anterior view"

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.