<prompt> Which structure passes through Guyons canal?Ulnar nerveMedian nerveRadial nerveFlexor carpi radialis  <response>: Ans. A Ulnar nerveRef: Grays Anatomy review E-book, P 336Clinical Correlates: Guyons Canal Syndrome Guyons canal ulnar tunnel is formed by the pisiform, hook of the hamate, and pisohamate ligament, deep to the palmaris brevis and palmar carpal ligament and transmits the ulnar nerve and artery. Guyons canal syndrome is an entrapment of the ulnar nerve in the Guyons canal. Symptoms: Pain, numbness, and tingling in the ring and little fingers, followed by loss of sensation and motor weakness. Rx: Surgical decompression of the nerve. 