pelvis, bony, basin-shaped structure that supports the organs of the lower abdomen. It receives the weight of the upper body and distributes it to the legs; it also forms the base for numerous muscle attachments. In the human pelvis there are two large hip bones, each consisting of three fused bones, the illium, ischium, and pubis. The hip bones form a ring around a central cavity. The fused terminal segments of the spine, known as the sacrum and coccyx, connect the hip bones at the back of the central cavity; a fibrous band connects them at the front. In women the pelvis is wider and has a larger capacity than in men, a condition that reflects the child-bearing function in women. See skeleton.