What is pectinate muscles?

Pectinate muscles, also known as musculi pectinati, are muscular ridges located on the inner wall of the right atrium of the heart. These muscles are distinct in appearance, resembling the teeth of a comb, which is where they get their name (pectinate meaning comb-like).

Pectinate muscles are primarily found in the atria of the heart, specifically in the right atrium, where they are more prominent compared to the left atrium. They are thought to aid in increasing the contractile force of the atrial muscle, allowing for more effective pumping of blood into the ventricles.

While the exact function of pectinate muscles is not fully understood, they are believed to play a role in maintaining the structure and function of the heart by helping to regulate blood flow and contribute to the overall efficiency of the heart's pumping action.

Pectinate muscles can sometimes be mistaken for a condition known as pectus carinatum, which is a chest wall deformity characterized by a protrusion of the sternum. However, pectinate muscles are a normal anatomical feature of the heart and should not be confused with this condition.