The humerus is the only bone in the upper arm. At the end of the humerus is two bones: the radius and the ulna. These two long bones allow us to twist our hands from side to side. At the end of the radius and ulna is the carpals or wrist. The carpals are not, however, where most people think their wrist is. The true wrist, the carpus, is at what most people consider the base of their hand. The palm of the hand is supported by the metacarpals. Phalanges make up the fingers. Each finger, with the exception of the thumb, has three phalanges. The thumb has only two phalanges.
The pelvis is the connection between the rest of the body and the lower extremities. It also provides support for the internal organs. The flaring sides of the pelvis is called the ilium. The two ring shaped portions located inferior to the hip sockets are called ischium. The femur is the bone of the thigh. Itís length can be roughly calculated by taking one-quarter of a personís height. The patella, or kneecap, dose two things: it guards the knee joint against blows, and it improves the leverage of thigh muscles which raise the lower leg. The tibia and fibula form the lower leg. Their joints, tibiofibular joints, do not allow for much movement, unlike the joints of the radius and ulna. Of these two bones, only the tibia bears weight. The fibula serves only as an attachment place for muscles.
The foot is much like the hand in the way the bones are grouped. The first group of bones, the tarsals, forms half of the foot. The calcaneus, is the bone that forms the heal of the foot, and the talus is the connection point of the foot and the tibia and fibula. The rest of the foot, no including the toes, are metatarsals. The toes, like the fingers, are phalanges. Also like the fingers, each toe has three phalanges with the exception of the great toe, or the big toe, which only has two phalanges.
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