The pelvis or pelvic bone is a ring-shaped structure of the bones situated at the lower end of the trunk. There are three bones in the pelvis ilium, ischium and pubis which grow along with the person. There are strong ligaments which join the pelvic bone to the sacrum (large triangular bone) at the bottom of the spine. Thus, a bowl-like cavity is formed below the rib cage. There is aetabulum (hollow) cup on both the sides of the pelvis which acts as the socket for the hip joint. Most of the digestive and reproductive organs are situated within the pelvic bone region. The blood vessels and large nerves which run up to the legs pass through the pelvic bone. The pelvic bone also serves as a point of attachment for the muscles which reach to the trunk of the body and down the legs.