Lesser pelvis

The lesser pelvis (or "true pelvis") is the space enclosed by the pelvic girdle and below the pelvic brim: between the pelvic inlet and the pelvic floor.

This cavity is a short, curved canal, deeper on its posterior than on its anterior wall.

Some[who?] consider this region to be the entirety of the pelvic cavity.

Others[who?] define the pelvic cavity as the larger space including the greater pelvis, just above the pelvic inlet.

The lesser pelvis is bounded in front and below by the superior rami of the symphysis pubis; above and behind, by the sacrum and coccyx; and laterally, by a broad, smooth, quadrangular area of bone, corresponding to the inner surfaces of the body and superior ramus of the ischium, and the part of the ilium below the arcuate line.

Roof: pelvic brim Posterior: sacrum, coccyx Lateral: obturator internus Anterior: pubic symphysis Floor: pelvic floor

The lesser pelvis contains the pelvic colon, rectum, bladder, and some of the sex organs.

The rectum is at the back, in the curve of the sacrum and coccyx; the bladder is in front, behind the pubic symphysis. In the female, the uterus and vagina occupy the interval between these viscera.

The pelvic splanchnic nerves arising at S2-S4 are in the lesser pelvis.