What nerve innervates the teres minor muscle?

The teres minor muscle is primarily innervated by the axillary nerve. This nerve is a branch of the posterior cord of the brachial plexus, which is responsible for the motor function of the deltoid and teres minor muscles. The axillary nerve emerges from the brachial plexus, specifically innervating the skin over the lateral aspect of the shoulder and providing motor innervation to the teres minor, which plays a crucial role in external rotation and adduction of the arm at the shoulder joint.

Understanding the role of the axillary nerve is essential for recognizing how it facilitates movement and stability in the shoulder, especially in conjunction with the deltoid muscle. The teres minor also works together with the rotator cuff muscles to stabilize the shoulder joint during various arm movements. This anatomical connection highlights the importance of the axillary nerve in shoulder mechanics.