phalangen

Phalangen are the bones that form the fingers and toes in humans and many other vertebrates. In humans, each hand contains 14 phalanges, with three phalanges in each of the four fingers (proximal, middle, and distal) and two in the thumb (proximal and distal). The foot has the same basic arrangement, with 14 phalanges per foot: three in each of the four smaller toes and two in the big toe.

Phalangen are named by their location along the digit. Proximal phalanges are closest to the hand or foot, distal phalanges are at the fingertip or toe tip, and middle phalanges lie between them. The middle phalanx is present in all digits except the pollex (thumb) and the hallux (big toe), which lack a middle phalanx. Each phalanx is connected to its neighbor by interphalangeal joints, and to the corresponding metacarpal or metatarsal bone by a metacarpophalangeal or metatarsophalangeal joint.

Functionally, phalanges provide structural support and enable fine motor control and weight distribution during gait. They are among the most commonly fractured bones in the hands and feet, particularly the distal phalanges near the nails or tips of the toes. Developmentally, phalanges ossify from cartilage through endochondral ossification, with primary centers appearing before birth and secondary centers forming in late childhood for the distal phalanges.

Phalangen show limited variation across humans but differ among species according to locomotion and manipulation needs. In clinical contexts, injuries to the phalanges are routinely treated with immobilization, reduction, or surgical stabilization, depending on fracture type and location.