The pelvic brim is the edge of the

pelvic inlet The pelvic inlet or superior aperture of the pelvis is a planar surface which defines the boundary between the pelvic cavity and the abdominal cavity (or, according to some authors, between two parts of the pelvic cavity, called lesser pelvis an ...

. It is an approximately

Mickey Mouse Mickey Mouse is an animated cartoon Character (arts), character co-created in 1928 by Walt Disney and Ub Iwerks. The longtime mascot of The Walt Disney Company, Mickey is an Anthropomorphism, anthropomorphic mouse who typically wears red sho ...

head-shaped line passing through the prominence of the

sacrum The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30. The sacrum situates at the upper, back part o ...

, the

arcuate ''Arcuate'' (Latin for "curved") can refer to: Anatomy * Arcuate fasciculus * Arcuate line (disambiguation) * Arcuate artery (disambiguation), several arteries * Arcuate nucleus * Arcuate nucleus (medulla) * Arcuate ligaments of the diaphragm * A ...

and pectineal lines, and the upper margin of the

pubic symphysis The pubic symphysis is a secondary cartilaginous joint between the left and right superior rami of the pubis of the hip bones. It is in front of and below the urinary bladder. In males, the suspensory ligament of the penis attaches to the pubi ...

Structure

The pelvic brim is an approximately

head-shaped line passing through the prominence of the

, the

and pectineal lines, and the upper margin of the

. The pelvic brim is obtusely pointed in front, diverging on either side, and encroached upon behind by the projection forward of the promontory of the

. The oblique plane passing approximately through the pelvic brim divides the internal part of the

pelvis The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

(

pelvic cavity The pelvic cavity is a body cavity that is bounded by the bones of the pelvis. Its oblique roof is the pelvic inlet (the superior opening of the pelvis). Its lower boundary is the pelvic floor. The pelvic cavity primarily contains the reproduc ...

) into the false or greater pelvis and the true or

lesser pelvis The pelvic cavity is a body cavity that is bounded by the bones of the pelvis. Its oblique roof is the pelvic inlet (the superior opening of the pelvis). Its lower boundary is the pelvic floor. The pelvic cavity primarily contains the reprodu ...

. The false pelvis, which is above that plane, is sometimes considered to be a part of the

abdominal cavity The abdominal cavity is a large body cavity in humans and many other animals that contains many organs. It is a part of the abdominopelvic cavity. It is located below the thoracic cavity, and above the pelvic cavity. Its dome-shaped roof is th ...

, rather than a part of the pelvic cavity. In this case, the pelvic cavity coincides with the true pelvis, which is below the above-mentioned plane. The

urinary bladder The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine ente ...

lies just above the anterior pelvic brim. The

sigmoid colon The sigmoid colon (or pelvic colon) is the part of the large intestine that is closest to the rectum and anus. It forms a loop that averages about in length. The loop is typically shaped like a Greek letter sigma (ς) or Latin letter S (thus ' ...

also passes close to the pelvic brim.

Clinical significance

The pelvic brim may be a site of compression of structures that pass through the

. This can include the femoral nerves, which may occur during

abdominal surgery The term abdominal surgery broadly covers surgical procedures that involve opening the abdomen ( laparotomy). Surgery of each abdominal organ is dealt with separately in connection with the description of that organ (see stomach, kidney, liver, ...

Structure

Clinical significance

See also

Additional images

References

External links