The Pectoralis minor
is a thin, triangular muscle, situated at the upper part of the chest
, beneath the Pectoralis major
Origin and insertion
It arises from the upper margins and outer surfaces of the third, fourth, and fifth ribs
, near their cartilages
and from the aponeuroses
covering the Intercostalis
The fibers pass upward and lateralward and converge to form a flat tendon, which is inserted into the medial border and upper surface of the coracoid process of the scapula.
The pectoralis minor muscle is covered anteriorly (superficially) by the clavipectoral fascia
. The medial pectoral nerve
pierces the pectoralis minor and the clavipectoral fascia.
The Pectoralis minor depresses the point of the shoulder, drawing the scapula downward and medialward toward the thorax, and throwing the inferior angle
Origin from second, third and fourth or fifth ribs. The tendon of insertion may extend over the coracoid process to the greater tubercle. May be split into several parts. Absence rare.