Pectinate muscles
（重定向自Pectinate muscle）
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The pectinate muscles (musculi pectinati) are parallel ridges in the walls of the atria of the heart. They are so-called because of their resemblance to the teeth of a comb as in pecten.
Behind the crest (crista terminalis) of the right atrium the internal surface is smooth. Pectinate muscles make up the part of the wall in front of this, the right atrial appendage.