Anatomy of the pelvic cavity

The pelvic cavity is a funnel-shaped space surrounded by pelvic bones and it contains organs, such as the urinary bladder, rectum, and pelvic genitals, to name a few.

The pelvic cavity and the abdominal cavity together form the larger abdominopelvic cavity.

The pelvic cavity is bounded superiorly by the pelvic inlet, which connects it to the abdominal cavity, and inferiorly, it’s bounded by a group of muscles and the fascia surrounding them, called the pelvic floor or pelvic diaphragm which is suspended above the pelvic outlet, with its central portion dipping below it.

The pelvic cavity also has an anteroinferior wall, two lateral walls, and a posterior wall.

So let’s start with the anteroinferior wall, formed by the bodies and rami of pubic bones, and the pubic symphysis.

Each pubic bone has three parts: a body and a superior and inferior ramus. The body of the pubic bone is the thickest, most anterior part of the pubic bone.

Anteriorly, the bodies of the right and left pubic bones are joined together in the median plane to form the pubic symphysis.

Now, in an anatomical position, the pelvis is tilted in the anterior-posterior plane, making the pubic bones and pubic symphysis act more like a weight bearing floor than an anterior wall.

The lateral walls of the pelvic cavity are formed by the right and left hip bones.

Each hip bone has an inferior opening called the obturator foramen, which is formed by the pubis and the ischium.

The foramen is partially covered by a membrane called the obturator membrane.

This membrane and the pelvic surfaces of the ilium and ischium give origin to a muscle called the obturator internus which pads most of the lateral pelvic wall.