Anatomy of Hand Muscles and Nerve Innervation

• The hand muscles discussed are called intrinsic hand muscles, which originate in the forearm or even the arm and insert in the hand.
• There are three thenar muscles acting on the thumb: abductor pollicis brevis, flexor pollicis brevis, and opposen pollicis. Their innervation is by the recurrent branch of the median nerve.
• The hypothenar muscles act on the pinkie and include three muscles: abductor digiti minimi, digit i minimize, and opponens digiti minimi. The innervation is by the ulnar nerve via Gianni's canal.
• The lumbricals are four muscles that arise from the flexor digitorum profundus tendons, originate in the palm of the hand, and insert on the back of the digits. They flex the metacarpophalangeal joint but extend the interphalangeal joints, which is unique for this joint.
• The adductor pollicis muscle has a traverse head and an oblique head, both originating from the third metacarpal and carpal bones, and inserting on the proximal phalanx of the thumb. It causes thumb adduction.
• The dorsal and palmar interosseous muscles are responsible for abducting and adducting fingers, respectively. The dorsal interossei muscles are innervated by the ulnar nerve.
• The text includes a discussion of the anatomy of the hand and the way the nerves (median and ulnar) innervate specific muscles. The author also mentions a cadaver demonstration of muscle actions.

Test your knowledge of hand anatomy, intrinsic hand muscles, and nerve innervation with this quiz. Explore the functions and origins of specific hand muscles, as well as their innervation by the median and ulnar nerves. Gain insights into the unique actions and features of the thenar, hypothenar, lumbricals, adductor pollicis, and interosseous muscles.