Which spinal nerves comprise the brachial plexus?

The spinal nerves that comprise the brachial plexus are indeed C5 through T1. The brachial plexus is a network of nerves that originates from the lower cervical spine and upper thoracic spine, specifically from the fifth cervical nerve (C5) to the first thoracic nerve (T1). This grouping of nerves is responsible for the motor and sensory innervation to the upper limb, including the shoulder, arm, and hand.

The roots of the brachial plexus are significant as they combine to form trunks, divisions, cords, and branches that give rise to the major nerves of the upper limb, such as the musculocutaneous, radial, ulnar, and median nerves. Understanding that the brachial plexus consists specifically of the C5 to T1 spinal nerves is crucial for identifying how various nerve injuries can impact arm function and sensory perception.

The other options do not align with the anatomical organization of the brachial plexus. The first option, which includes C1-C5, extends too high and does not involve the T1 nerve. The second option, L1-L5, pertains to the lumbar plexus, which innervates the lower limb, not the upper limb. The