Upper arm

Upper Arm

The upper arm or the brachium is the region of the human body extending from the shoulder to the elbow. It is one of the most important parts of the human anatomy, playing a crucial role in the overall function of the arm.

Anatomy of the Upper Arm

The upper arm is primarily made up of the humerus, the longest bone in the arm. The humerus connects the shoulder to the elbow, forming a ball and socket joint at the shoulder and a hinge joint at the elbow. The upper arm is also home to several important muscles, including the biceps brachii, triceps brachii, and brachialis.

Bones

The humerus is the only bone in the upper arm. It is a long bone, characterized by a rounded head, a narrow neck, and two sets of processes (projections). The head of the humerus fits into the glenoid cavity of the scapula, forming the shoulder joint.

Muscles

The upper arm houses three major muscles: the biceps brachii, triceps brachii, and brachialis. The biceps brachii is a two-headed muscle located on the front of the arm, and it is primarily responsible for arm flexion and forearm supination. The triceps brachii is a three-headed muscle located on the back of the arm, and it is primarily responsible for arm extension. The brachialis is located underneath the biceps brachii and it is a major contributor to elbow flexion.

Function of the Upper Arm

The upper arm plays a crucial role in the overall function of the arm. It allows for the flexion and extension of the forearm at the elbow, the rotation of the forearm, and the abduction and adduction of the arm at the shoulder. The upper arm muscles also play a key role in the movements of the hand and fingers.

See Also

• Arm
• Forearm
• Elbow
• Shoulder
• Muscular system
• Skeletal system