Phalanges of the foot

The toe bones (Latin Ossa digiti pedis or Ossa digitorum pedis) are the knöchernden support elements of the toes. In mammals, each fully trained finger has three bony support members as proximal phalanx, media and distalis ( " body-hugging, medium and body further phalange bones "), even phalanx I, II and III ( AltGr. Phalanx " battle line of warriors ", " bole ", " roll " or "role" ) are called. The big toe has only two phalanges, the middle one is not formed. The connections between the metatarsal and proximal phalanx and the phalanx bone with each other are the toe joints.

Structure in humans

The toe bones are typical of the structure of bones and are similar in structure to the finger bones. It differs from close to the body (proximal ) to distally ( distal) phalanges base ( base phalanx ), body ( corpus phalanx ) and head (caput phalanx ).

The toe bone base of the proximal phalanx bears a concave articular surface for the first metatarsophalangeal joint, the articular surfaces of the base of the lower phalange bones a sagittal guide comb. The articular surfaces of the head of proximal phalanx and media are called trochlea. The head of the end member is flattened and bears fußflächenseitig ( plantar ) roughness, the tuberosity of phalanx distalis pedis.

Plantar side of the first metatarsophalangeal joint in humans are two small sesamoid bones, which are embedded in the tendons of the abductor hallucis adductor hallucis respectively.

Comparative Anatomy

In ungulates the three phalanx bones as bondage (Os compedale ), Kron ( Os coronal ) and coffin bone are called (Os ungulare ), at the distal phalanx predators as " claw leg " (Os unguiculare ) is called. The non-existent in the dog normally Wolf claw - the rudiment of the first toe - has only one phalange.

Fußrückenseitig At the base of the proximal phalanx of the fourth toe to media in ruminants the insertion of the extensor digitorum lateralis. Fußflächenseitig have all four-footed mammals on the middle phalanx of the toe support a roughness ( Tuberosits flexoria ) the recognition of the superficial digital flexor.

The distal phalanx is due to the different first ground contact at the four-footed mammals marked differences to man. Here, a distinction is a joint surface ( articular facies ), a wall surface (facies parietalis ) and a sole surface (facies solearis ) in animal anatomy. At the articular surface of the distal phalanx an articular surface is for the navicular bone ( articular facies sesamoidea ). The plantar surface bears the attachment point for the flexor digitorum profundus, as the tubercle flexorium (ruminants, carnivores, pigs) or Facies flexoria ( horses) is called. At the front coronet, the processus rises extensor ( at predators as Crista unguicularis called ) for preparation of the extensor digitorum longus.

In birds, the number and position of the toe bones vary (→ Birdfoot ). The number of phalanges is always one greater than the atomic number of the corresponding toe: So the first toe has two phalanges, the second toe three and so on.