Nerve Supply of Arm

The nerve supply to the arm is provided by branches of the brachial plexus, a network of nerves originating from the spinal cord in the neck. The nerve supply to the arm in detail is given below:

Brachial Plexus

• Formed by the anterior rami (nerve roots) of spinal nerves C5 to T1.
• Located in the neck and axilla.
• Gives rise to several nerves that innervate the muscles and skin of the arm.

Major Nerves of the Brachial Plexus

1. Musculocutaneous Nerve (C5-C7)
   • Innervates the muscles in the anterior compartment of the arm, including the biceps brachii and brachialis.
   • Supplies sensation to the lateral aspect of the forearm.
2. Median Nerve (C6-T1)
   • Innervates muscles in the anterior compartment of the forearm (except flexor carpi ulnaris and part of the flexor digitorum profundus).
   • Provides sensation to the lateral palm and digits 1-3 and the lateral half of digit 4 (thumb, index, middle, and half of the ring finger).
3. Ulnar Nerve (C8-T1)
   • Innervates muscles in the anterior and posterior compartments of the forearm.
   • Supplies sensation to the medial aspect of the hand and digits 4 and 5.
4. Radial Nerve (C5-T1)
   • Innervates muscles in the posterior compartment of the arm and forearm.
   • Provides sensation to the posterior arm, forearm, and hand (except digits 4 and 5).

Other Nerves

• Axillary Nerve: Branch of the posterior cord of the brachial plexus; innervates the deltoid and teres minor muscles.
• Medial and Lateral Pectoral Nerves: Innervate the pectoralis major muscles.
• Dermatomes: Each spinal nerve root contributes to a specific dermatome, an area of skin innervated by sensory fibers from that nerve root. Dermatomes from C5 to T1 cover various regions of the arm and forearm, providing sensory input.

The arm body part is the upper limb of vertebrates. Anatomy of the arm involves the detailed study of its bones, muscles, nerves, blood vessels, and connective tissues. Learning about the arm muscles and arm bones helps in understanding how movements are coordinated and how injuries can be prevented or treated.

In this article, we will cover the anatomy of the arm and read about the nerve supply and blood supply in the arm along with arm muscles and bones, in detail.