What is the difference between digits and phalanges

The flexor muscles are located on the anterior volar surface of the forearm and are attached by tendons to the phalanges of the fingers.

The extensor muscles are on the dorsal surface of the forearm and are similarly connected. The thumb has two separate flexor muscles that move the thumb in opposition and make grasping possible. The hand has 27 bones: the 8 bones of the carpus wrist , arranged in two sets of four; the 5 bones of the metacarpus, one to each digit; and the 14 digital bones, or phalanges, 2 in the thumb and 3 in each finger. The carpal bones fit into a shallow socket formed by the bones of the forearm. Each metacarpal bone has a proximal base, a shaft, and a distal head.

The base of each metacarpal contacts the distal row of carpal bones to form the carpometacarpal joint. The head of each metacarpal contacts the proximal. The proximal row of phalanges articulates with the middle row of phalanges at the proximal interphalangeal PIP joints , the middle and distal rows of phalanges articulate at the distal interphalangeal DIP joints. The superficial palmar branch then passes through the thenar compartment, and provides a minor contribution to the superficial palmar arch.

The deep palmar branch of the radial artery is the major contributor to the deep palmar arch. It courses around the base of the thumb and passes dorsal to the 1st MC to gain access to the thenar space where it becomes the deep palmar arch.

Anatomy of the Hand. The Skeleton of the Hand The hand has 27 bones: the 8 bones of the carpus wrist , arranged in two sets of four; the 5 bones of the metacarpus, one to each digit; and the 14 digital bones, or phalanges, 2 in the thumb and 3 in each finger.

The head of each metacarpal contacts the proximal at a metacarpophalangeal MP joint. They include the Thenar and Hypothenar muscles, which function in positioning of the thumb and small finger for pinching; and the Interossei and Lumbricals, which insert into proximal phalanges and extensor hoods, function in metacarpal phalangeal joint flexion and interphalangeal joint extension.

See the table below for a summary of the individual intrinsic muscles and their function Intrinsic Muscles of the Hand Muscle Origin Insertion Action Innervation Muscles acting on the Second through Fifth Digits Dorsal interossei 4 ulnar side of 1st MC; both sides of 2nd-4th MC; radial side of 5th MC Tubercle of proximal phalanx and dorsal aponeurosis: radially on 2nd and 3rd digits, ulnarly on 3rd and 4th digit Abduct 2nd-4th digits from midline; flex MCP joint, extend PIP and DIP joints Ulnar nerve C8-T1, anterior Palmar interossei 3 ulnar side of 2nd and radial side of 4th-5th MC Tubercle of proximal phalanx and dorsal aponeurosis: ulnarly on 2nd digit, radially on 4th and 5th digits Adduct 2nd, 4th, and 5th digits to the midline of the hand.

The 14 bones that are found in the fingers of each hand and also in the toes of each foot. Each finger has 3 phalanges the distal, middle, and proximal ; the thumb only has 2. Carpal bones. The 8 bones that create the wrist. The 2 rows of carpal bones are connected to 2 bones of the arm--the ulna bone and the radius bone. Numerous muscles, ligaments, tendons, and sheaths can be found within the hand.

The muscles are the structures that can contract, allowing movement of the bones in the hand. The ligaments are fibrous tissues that help bind together the joints in the hand.

The sheaths are tubular structures that surround part of the fingers.