hand

The hand is the distal portion of the upper limb that enables a wide range of precise and powerful movements. It consists of the palm, dorsum of the hand, and digits, extending from the wrist and supported by a complex arrangement of bones, joints, muscles, tendons, nerves, vessels, and skin.

Anatomy includes the carpal bones of the wrist, the five metacarpal bones of the palm, and the fourteen phalanges of the fingers and thumb. The principal joints are the radiocarpal and midcarpal joints at the wrist, the carpometacarpal joints (including the thumb’s saddle joint), the metacarpophalangeal joints, and the interphalangeal joints. The thumb has two phalanges, while the other digits have three.

Muscles of the hand are categorized as intrinsic (located within the hand, such as the thenar and hypothenar groups, interossei, and lumbricals) and extrinsic (originating in the forearm and acting through tendons to flex or extend the fingers). Tendons, ligaments, and pulleys coordinate movement, while the skin provides sensation and tactile feedback.

Nerve supply is primarily from the median and ulnar nerves, with the radial nerve contributing to dorsal hand sensation and extensor function. Blood supply comes from the radial and ulnar arteries, forming the palmar arches and supplying digital vessels.

Functionally, the hand enables grasping and manipulation through a combination of grip types and thumb opposition, underpinning daily tasks, tool use, and communication through gesture and touch. Common clinical issues include fractures of the distal radius or carpal bones, carpal tunnel syndrome, and conditions affecting tendon or nerve function.