It originates at the side of the chest from the upper 8 or 9 ribs; it inserts along the entire length of the anterior aspect of the medial border of the scapula.

The muscle is divided into three parts according to the points of insertion:[1] The serratus anterior is innervated by the long thoracic nerve, a branch of the brachial plexus.

The serratus anterior acts in concert with the upper and lower fibers of the trapezius muscle to sustain upward rotation of the scapula, which allows for overhead lifting.

The long thoracic nerve that supplies the serratus anterior muscle is vulnerable during certain types of surgery (for example, during lymph node clearance from the axilla for breast cancer).

[7] Functional demands have resulted in the evolution of individual muscles from the basal unit formed by the serratus anterior.

[7] In primates, the thoracic cage is wide and the scapula is rotated onto its posterior side to have the glenoid cavity face laterally.