What is the innervation of the teres minor?

The teres minor is a small muscle located in the shoulder area, specifically in the rotator cuff group. Its primary function is to assist in the lateral rotation of the arm at the shoulder joint. The muscle is innervated by the axillary nerve, which is a branch of the posterior cord of the brachial plexus.

The axillary nerve not only innervates the teres minor but also supplies the deltoid muscle and provides sensory innervation to the skin over the lateral part of the shoulder. This anatomical relationship is significant for both motor function and sensory feedback in that region.

The other options do not correspond to the correct innervation for the teres minor. For instance, the musculocutaneous nerve primarily innervates flexor muscles of the arm, while the subscapular nerve innervates the subscapularis and teres major muscles. The radial nerve is responsible for innervating the posterior compartment of the arm and forearm, which is unrelated to the teres minor's function. Understanding these associations helps reinforce the knowledge of nerve supply in the shoulder region.