The innervation of the pect-oralis major muscle is done by:
a. Long thoracic nerve
b. Lateral pectoral nerve
c. Intercostal nerves
d. Accessory nerve
e. Medial pectoral nerve
The correct answer is: b. Lateral pectoral nerve and e. Medial pectoral nerve.
The pectoralis major muscle is innervated by two nerves:
– The lateral pectoral nerve (C5-C7) innervates the clavicular head (upper portion) of the muscle.
– The medial pectoral nerve (C8-T1) innervates the sternocostal head (lower portion) of the muscle.
The other options are not correct:
– The long thoracic nerve (a) innervates the serratus anterior muscle, not the pectoralis major.
– The intercostal nerves (c) innervate the intercostal muscles and skin, not the pectoralis major.
– The accessory nerve (d) innervates the sternocleidomastoid and trapezius muscles, not the pectoralis major.