Pelvis is the bony structure that supports the lower abdomen. It surrounds the urinary bladder, the last portion of the large intestine, and, in women, the reproductive organs. A female’s pelvis is flatter and broader than a male’s, and it has a larger central cavity.
The spinal column joins the pelvis at the sacroiliac joints. The femurs (thigh bones) join the lower part of the pelvis in large ball-and-socket hip joints that allow the legs to move in many directions. Many large muscle masses lead from the pelvis to the femurs.
Two big, symmetrical hipbones form the pelvis. These bones join in front to form the pubic symphysis. In back, they form a strong union with the sacrum (five backbones joined to form a single bone). Each hipbone in an adult appears to be one solid bone. But it is formed by three bones, the ilium, ischium, and pubis, that unite as the body matures. The ilium is the broad, flat bone you feel when you rest your hand on the hip. When you sit down, much of your weight rests on the ischium. The pubis bones form two arches in front that join at the symphysis.
