To the tubercles on the digital extremities are attached the collateral ligaments of the metacarpophalangeal joints.This ridge separates two sloping surfaces for the attachment of the interossei dorsales. ![]() This surface is bounded by two lines, which commence in small tubercles situated on either side of the digital extremity, and, passing upward, converge and meet some distance above the center of the bone and form a ridge which runs along the rest of the dorsal surface to the carpal extremity. The dorsal surface presents in its distal two-thirds a smooth, triangular, flattened area which is covered in by the tendons of the extensor muscles.The medial and lateral surfaces are concave, for the attachment of the interosseus muscles, and separated from one another by a prominent anterior ridge.It presents three surfaces: medial, lateral, and dorsal. The body ( shaft) is prismoid in form, and curved, so as to be convex in the longitudinal direction behind, concave in front. Įach metacarpal bone consists of a body or shaft, and two extremities: the head at the distal or digital end (near the fingers), and the base at the proximal or carpal end (close to the wrist). The ring metacarpal is somewhat more mobile while the fifth metacarpal is semi-independent. The middle metacarpals are tightly united to the carpus by intrinsic interlocking bone elements at their bases. The index metacarpal is the most firmly fixed, while the thumb metacarpal articulates with the trapezium and acts independently from the others. The peripheral metacarpals (those of the thumb and little finger) form the sides of the cup of the palmar gutter and as they are brought together they deepen this concavity. ![]() The metacarpals form a transverse arch to which the rigid row of distal carpal bones are fixed. Structure Left hand shown with thumb on left. The metacarpal bones are analogous to the metatarsal bones in the foot. ![]() In human anatomy, the metacarpal bones or metacarpus form the intermediate part of the skeletal hand located between the phalanges of the fingers and the carpal bones of the wrist, which forms the connection to the forearm.
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