The pelvic inlet or superior aperture of the
pelvis is a planar surface which defines the boundary between 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 ...
and the
abdominal cavity (or, according to some authors, between two parts of the pelvic cavity, called lesser pelvis and greater pelvis). It is a major target of measurements of
pelvimetry.
Its position and orientation relative to the skeleton of the pelvis is anatomically defined by its edge, the
pelvic brim
The pelvic brim is the edge of the pelvic inlet. It is an approximately Mickey Mouse head-shaped line passing through the prominence of the sacrum, the arcuate and pectineal lines, and the upper margin of the pubic symphysis.
Structure
The pel ...
. The pelvic brim 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
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 ...
.
Occasionally, the terms pelvic inlet and pelvic brim are used interchangeably.
Boundaries
The edge of the pelvic inlet (pelvic brim) is formed as follows:
Diameters
The diameters or conjugates of the pelvis are measured at the pelvic inlet and outlet and as oblique diameters.
Two diameters may be measured from the outside of the body using a
pelvimeter
Additional images
Skeletal pelvis-pubis.svg, Pelvis
Konjugata vera.jpg, Conjugata vera as measured on sagittal MRI
File:Low-dose CT of transverse diameter of pelvic inlet.jpg, Low-dose CT scan of the transverse diameter of the pelvic inlet, as part of pelvimetry
File:Low-dose CT of obstetric conjugate.jpg, Obstetric conjugate, as a measure of the pelvic inlet in the sagittal plane
The sagittal plane (; also known as the longitudinal plane) is an anatomical plane that divides the body into right and left sections. It is perpendicular to the transverse and coronal planes. The plane may be in the center of the body and div ...
See also
*
pelvic outlet
External links
*
* - transverse diameter is blue pipecleaner, anteroposterior or conjugate diameter is red pipecleaner
Image at mun.ca* (, )
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Pelvis