The anatomy of the hand consists of various features on the surface and interior of the hand. This includes bones, joints, nerves, and tendons. Individual aspects of the anatomy of the hand, such as the fingertips, also have specific structures worth noting when discussing the anatomy of the hand.
Surface features of the hand include various creases and segments. Creases include the distal palmar crease that arises near the index finger and continues to the ulnar border, opposite the thumb. The proximal palmar crease lies directly below the distal palmar crease. Segments include the small, ring, middle and index fingers, and the thumb.
Phalanges are the different bones of the fingers and thumb. Distal phalanges are located at the tip of the finger, the middle phalanges are in the center, and the proximal phalanges are the part of the finger closest to the palm. The thumb does not have a middle phalange, and instead has only a distal phalange and proximal phalange.
Other bones of the hand make up the palm and the area adjoining the wrist. Metacarpals are the main bones of the hand. They rest below the proximal phalanges. Some of the additional bones of the hand that make up the base of the hand closest to the wrist include the hamate, pisiform, lunate, trapezoid, and scaphoid.
Joints help provide the hand with movement and allow humans to grasp objects and perform other daily tasks. The joints of the fingers include the distal interphalangeal, proximal interphalangeal, and the metacarpophalangeal joint, which joins the proximal phalanges to the metacarpals. Specifically, the joint that hinges the thumb is the carpometacarpal, also referred to as the basilar joint.
Various nerves are also included in the anatomy of the hand. These nerves provide skin with sense of touch and the ability to feel pain, often from sensations such as heat and cold. Some examples include the ulnar nerve, radial nerve, and the digital nerve.
The fingertips have specific anatomical features. This includes the nail plate, nail fold, and lunula. Tendons which help the fingertip bend include the insertion extensor tendon, which runs along the top of the finger, and the insertion flexor tendon, which runs along the palm side of the fingertip. These tendons connect the distal and middle phalanges.
Various arteries and muscles also make up the anatomy of the hand. Arteries include the deep palmar, radial, and superficial ulnar arteries. Muscles in the hand include the adductor pollicis, interosseous, and lumbrical.