The pelvis is the part of the body located between the abdomen and the thighs. The term 'pelvis' can refer to the pelvic skeleton (also known as the pelvic girdle), which is a bony structure embedded in the lower part of the trunk. The pelvic girdle connects the axial skeleton to the free lower extremities.
Structure of pelvis
The pelvic skeleton is composed of the following bones:
There are four joints between the bones of the pelvis:
- Sacroiliac joints (2) - articulations between the ilium and the sacrum;
- Sacrococcygeal symphysis - between the sacrum and the coccyx;
- Pubic symphysis - between both bodies of the pubic bones in the anterior midline.
Several ligaments extend between the lateral borders of the sacrum to various bony landmarks on the pelvis, aiding stability to the pelvis.
Functions of pelvis
The pelvic skeleton is strong and rigid, adapted to serve several roles in the human body, including:
- Transferring weight from the upper axial skeleton to the lower extremities, especially during motion;
- Providing attachment for many muscles and ligaments used in locomotion;
- Enclosing and protecting abdominopelvic and pelvic viscera (internal organs);
- Providing natural childbirth, when the neonate passes through the birth canal which lies in the pelvic girdle.