The lesser pelvis is that part of the space enclosed by the skeleton of the pelvis

Pelvis

In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...

 which is situated between the pelvic inlet

Pelvic inlet

The pelvic inlet or superior aperture of the pelvis is a planar surface which is typically used to define the boundary between the pelvic cavity and the abdominal cavity .Its position and orientation relative to the skeleton of the pelvis is anatomically defined by its...

 and the pelvic floor

Pelvic floor

The pelvic floor or pelvic diaphragm is composed of muscle fibers of the levator ani, the coccygeus, and associated connective tissue which span the area underneath the pelvis. The pelvic diaphragm is a muscular partition formed by the levatores ani and coccygei, with which may be included the...

. Some authors call this cavity the pelvic cavity

Pelvic cavity

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. Some others define the pelvic cavity as a larger space, nemely the whole space enclosed by the skeleton of the pelvis, formed by the lesser pelvis (below the pelvic inlet) and the greater or false pelvis

Greater pelvis

The greater pelvis is a portion of the cavity surrounded by the skeleton of the pelvis, situated above and in front of the pelvic brim...

 (above the pelvic inlet).

Boundaries

The roof of the lesser pelvis is the pelvic inlet

Pelvic inlet

The pelvic inlet or superior aperture of the pelvis is a planar surface which is typically used to define the boundary between the pelvic cavity and the abdominal cavity .Its position and orientation relative to the skeleton of the pelvis is anatomically defined by its...

, an oblique planar surface defined by the pelvic brim

Pelvic brim

The pelvic brim is the edge of the pelvic inlet. It is an approximately apple-shaped line passing through the prominence of the sacrum, the arcuate and pectineal lines, and the upper margin of the pubic symphysis....

. Its lower boundary is the pelvic floor

Pelvic floor

The pelvic floor or pelvic diaphragm is composed of muscle fibers of the levator ani, the coccygeus, and associated connective tissue which span the area underneath the pelvis. The pelvic diaphragm is a muscular partition formed by the levatores ani and coccygei, with which may be included the...

. The lesser pelvis is bounded in front and below by the pubic symphysis

Pubic symphysis

The pubic symphysis or symphysis pubis is the midline cartilaginous joint uniting the superior rami of the left and right pubic bones. It is located anterior to the urinary bladder and superior to the external genitalia; for females it is above the vulva and for males it is above the penis...

 and the superior rami of the pubes; above and behind, by the pelvic surfaces of the sacrum and coccyx, which, curving forward above and below, contract the superior and inferior apertures of the cavity; laterally, by a broad, smooth, quadrangular area of bone, corresponding to the inner surfaces of the body and superior ramus of the ischium and that part of the ilium which is below the arcuate line

Arcuate line

In anatomy, an arcuate line is any structure that is curvilinear.* Arcuate line * Arcuate line...

.

From this description it will be seen that the cavity of the lesser pelvis is a short, curved canal, considerably deeper on its posterior than on its anterior wall.

Contents

The lesser pelvis contains, in the fresh subject, the pelvic colon, rectum

Rectum

The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...

, bladder

Urinary bladder

The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...

, and some of the organs of generation.

The rectum

Rectum

The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...

 is placed at the back of the pelvis, in the curve of the sacrum

Sacrum

In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...

 and coccyx

Coccyx

The coccyx , commonly referred to as the tailbone, is the final segment of the vertebral column. Comprising three to five separate or fused vertebrae below the sacrum, it is attached to the sacrum by a fibrocartilaginous joint, the sacrococcygeal symphysis, which permits limited movement between...

; the bladder is in front, behind the pubic symphysis

Pubic symphysis

The pubic symphysis or symphysis pubis is the midline cartilaginous joint uniting the superior rami of the left and right pubic bones. It is located anterior to the urinary bladder and superior to the external genitalia; for females it is above the vulva and for males it is above the penis...

.

In the female the uterus

Uterus

The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...

 and vagina

Vagina

The vagina is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the...

occupy the interval between these viscera.