Tubular bones. These are composed of spongy and compact substance forming a tube with a marrow cavity; they perform all three functions of the skeleton (support, protection, and movement). Long tubular bones (arm bone, forearm bones, thigh bone, and log bones) are supports and long levers of movement and they have enchondral ossification foci in both epiphyses (biepiphyseal bones) but not in the diaphysis. Short tubular bones (metacarpal, metatarsal, phalanges)are short levers of movement; an enchondral ossification focus is found only in one (true) epiphysis (monoepiphyseal bones).ICD 10 Coding will teach all these for the medical coding and billing for the proper collections.