Which muscle is located in the back of the upper arm?

The triceps muscle is located at the back of the upper arm and plays a crucial role in the extension of the elbow joint. When the triceps contracts, it pulls on the olecranon process of the ulna, effectively straightening the arm. This muscle comprises three distinct parts—long head, lateral head, and medial head—each contributing to its overall function and structure.

In contrast to this, the biceps muscle is located at the front of the upper arm and is primarily responsible for flexing the elbow and supinating the forearm. The deltoid muscle, found on the shoulder, is involved in lifting and rotating the arm, while the latissimus dorsi is a large muscle located in the lower back that contributes to movements of the shoulder. Understanding the specific locations and functions of these muscles is essential in anatomy and physiology, especially in contexts related to movement and rehabilitation.