What are the nerve roots of the brachial plexus?

The correct response identifies the nerve roots of the brachial plexus as C5 to T1, which is essential for understanding the structure and function of the nerves that supply the upper limb. The brachial plexus is formed from the anterior rami of spinal nerves C5, C6, C7, C8, and T1 and is responsible for innervating the muscles and skin of the shoulder, arm, forearm, and hand.

This brachial plexus is crucial not only for motor control but also for sensory input from the upper extremities. Each of these spinal nerves contributes to different trunks and divisions that further branch out into cords and ultimately into peripheral nerves like the radial, ulnar, and median nerves.

In contrast, the other choices pertain to different segments of the spinal cord. The option referencing C3-C5 is associated with the phrenic nerve, which primarily innervates the diaphragm and is important for respiration. The choices that include L1-L5 and S1-S5 refer to the lumbar and sacral plexuses, respectively, which are involved in the innervation of the lower limbs and pelvic region, not the upper limb. Understanding the specific roots that comprise the brach