Pectoral Region

Question 1

Pectoralis Major. (Location, origin, insertion, innervation and action)

Answer 1

Origin: Medial half of the clavicle; the manubrium; the body of the sternam; the costal cartilages of ribs 1-6; the anterior layer of the rectus sheath

Insertion: Crest of the greater tubercle of the humerus

Action: Adduction, internal rotation and flexion of the arm; assists in respiration when the shoulder is fixed.

Innervation: Medial and lateral pectoral nerves; the brachial plexus (C5 and T1)

Question 2

Pectoralis Minor. (Location, origin, insertion, innervation and action)

Answer 2

Origin: 3rd to 5th ribs.

Insertion: caracoid process of the scapula

Action: Pulls the scapulla medially forwards and downwards

Innervation: Medial and lateral pectoral nerves (C6-T1)