What structure houses the ulnar nerve?

The ulnar nerve is housed in the cubital tunnel, which is located at the elbow. This tunnel is formed by the medial epicondyle of the humerus and the olecranon process of the ulna, providing a protective passageway for the ulnar nerve as it travels down the arm. The anatomical structure allows for some degree of movement while protecting the nerve from mechanical stress and potential injury.

In contrast, the carpal tunnel is primarily associated with the median nerve and does not involve the ulnar nerve, making it irrelevant to the question. The metacarpal canal is not a recognized structure for containing the ulnar nerve, as it pertains more to the arrangement of bones in the hand rather than a protective passage for nerves. The radioulnar tunnel is typically associated with the muscles and not specifically designed for housing the ulnar nerve. Thus, the cubital tunnel is specifically recognized for its role in protecting and housing the ulnar nerve, making it the correct answer.