of this section, you will be able to:Classify BONES according to their shapesDescribe the function of each category of bonesThe 206 bones that compose the adult skeleton are divided into five categories based on their shapes (Figure 1). Their shapes and their functions are related such that each categorical shape of bone has a distinct function.Figure 1. Classifications of Bones. Bones are classified according to their shape.LONG BONESA long bone is ONE that is cylindrical in shape, being longer than it is wide. Keep in mind, however, that the term describes the shape of a bone, not its size. Long bones are found in the arms (humerus, ulna, radius) and legs (femur, tibia, fibula), as well as in the fingers (metacarpals, phalanges) and toes (metatarsals, phalanges). Long bones function as levers; they move when muscles contract.SHORT BONESA short bone is one that is cube-like in shape, being approximately equal in length, width, and thickness. The only short bones in the human skeleton are in the carpals of the wrists and the tarsals of the ankles. Short bones provide STABILITY and support as well as some limited motion.FLAT BONESThe term “flat bone” is somewhat of a misnomer because, although a flat bone is typically THIN, it is ALSO often curved. Examples include the cranial (skull) bones, the scapulae (shoulder blades), the sternum (breastbone), and the ribs. Flat bones serve as points of attachment for muscles and often protect internal organs.