The ulnar nerve arises from cervical nerve roots C8 and T1, traveling through the _________ trunk and the medial cord.

The ulnar nerve, which is crucial for hand and finger function, originates from the fifth and sixth cervical (C8) and first thoracic (T1) nerve roots. It travels through the lower trunk of the brachial plexus before continuing along the medial cord.

The lower trunk is specifically formed from the union of the C8 and T1 nerve roots, which makes it the appropriate pathway for the ulnar nerve. This trunk is key in distributing nerves that contribute to the functions of the forearm and hand. The medial cord arises from the lower trunk and contains fibers that will eventually give rise to the ulnar nerve.

It’s important to understand how the brachial plexus is structured, as it contains upper, middle, and lower trunks, each contributing differently to the formation of peripheral nerves, including those that travel to the arms and hands. Hence, understanding the anatomy and pathway of the ulnar nerve is critical for recognizing its function and potential sites of injury.