Which nerve is responsible for innervating the deltoid and teres minor muscles?

The axillary nerve is responsible for innervating both the deltoid and teres minor muscles. This nerve emerges from the brachial plexus and innervates the deltoid muscle, which plays a crucial role in shoulder abduction, and the teres minor, which is involved in shoulder external rotation.

The deltoid muscle is particularly significant as it contributes to the contour of the shoulder and is key in various arm movements. The teres minor, while smaller and less prominent, assists along with the rotator cuff muscles in stabilizing the shoulder joint and facilitating arm movements. The axillary nerve also carries sensory information from the skin over the deltoid muscle, further illustrating its importance in shoulder function.

Understanding the role of the axillary nerve emphasizes its critical function in voluntary arm movements and overall shoulder mechanics, which is essential for various activities in daily life and sports.