The wrist has eight carpal bones. In humans, these are small and angular in shape and structure. In quadruped animals, such as horses and cows, the carpals are also present on the knee area of the foreleg.
Primitive vertebrates had 12 carpal bones. The number has now reduced as a result of fusion in birds, reptiles and modern amphibians.
Carpals in humans are arranged in two rows in the hand. The distal row is closest to the fingers, while the proximal row is closer to the forearm. In addition to the eight carpal bones in the human hand, there are four joints known as articulations.