Corpus: Upper arm

The upper arm is the proximal segment of the upper limb, extending from the shoulder to the elbow. It connects to the forearm via the elbow joint and links the upper limb to the shoulder girdle and the trunk through the shoulder joint.

The humerus is the foundational bone of the upper arm, forming its osseous structure.

The humerus is a pivotal point for the attachment of various muscles, including shoulder, select back and chest muscles, and forearm muscles. However, the bulk of the upper arm's muscular mass consists of the upper arm muscles:

• biceps brachii muscle
• coracobrachialis muscle
• brachialis muscle
• triceps brachii muscle
• anconeus muscle

Note: Although anatomically part of the forearm, the anconeus muscle is developmentally associated with the triceps brachii muscle.

The primary artery in the upper arm is the brachial artery, which continues from the subclavian and axillary arteries. This artery bifurcates at the elbow joint into the radial and ulnar arteries.

Venous drainage in the upper extremity occurs through two main systems: superficial (epifascial) cutaneous veins and deep (subfascial) veins, including accompanying veins. These merge into the brachial vein, which runs parallel to the brachial artery.

The three major nerves of the arm are:

• ulnar nerve
• radial nerve
• median nerve

Another important nerve within the upper arm is the musculocutaneous nerve.

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