pelvic inlet (redirected from Superior circumference)

inlet /in·let/ (-let) a means or route of entrance.

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pelvic inlet  the upper limit of the pelvic cavity.

thoracic inlet  the elliptical opening at the summit of the thorax.

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pelvic inlet,

(in obstetrics) the inlet to the true pelvis, bounded by the sacral promontory, the horizontal rami of the pubic bones, and the top of the symphysis pubis. Because the infant must pass through the inlet to enter the true pelvis and to be born vaginally, the anteroposterior, transverse, and oblique dimensions of the inlet are important measurements to be made in assessing the pelvis in pregnancy. There are three anteroposterior diameters: the true conjugate, the obstetric conjugate, and the diagonal conjugate. The true conjugate can be measured only on radiographic films because it extends from the sacral promontory to the top of the symphysis pubis. Its normal measurement is 11 cm or more. The obstetric conjugate is the shortest of the three. It extends from the sacral promontory to the thickest part of the pubic bone and measures 10 cm or more. The diagonal conjugate is the most easily and commonly assessed because it extends from the lower border of the symphysis pubis to the sacral promontory. It normally measures 11.5 cm or more. The inlet is said to be contracted when any of these diameters is smaller than normal. The anteroposterior diameters are shorter than normal in the small gynecoid and platypelloid pelvis. The transverse diameter of the inlet is bounded by the inferior border of the walls of the iliac bones and is measured at the widest point. It is normally close to 13.5 cm but may be less in the small gynecoid pelvis and anthropoid pelvis. The oblique diameters of the pelvis extend from the juncture of the sacrum and ilium to the eminence on the ilium on the opposite side of the pelvis. Each oblique diameter measures nearly 13 cm. This dimension is smaller than normal in the small gynecoid and platypelloid pelves. See also android pelvis, anthropoid pelvis, gynecoid pelvis, platypelloid pelvis.

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inlet [in´let]

a means or route of entrance.

pelvic inlet the upper limit of the pelvis minor; called also pelvic brim and superior aperture of pelvis.

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inlet

a means or route of entrance.

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pelvic inlet

see pelvic inlet.

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pelvic

pertaining to the pelvis.

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pelvic abscess

commonest in horses as a result of a rectal tear during a manual examination. The tear is only mucosa deep and the infection is deposited in the pelvic fascia where an abscess develops. This has the potential to erode into the peritoneal cavity. The syndrome begins as a toxemia and fever caused by the local abscess but a common sequel is the abrupt appearance of severe abdominal pain and toxemic shock.

pelvic bone

os coxae, comprising the ilium, ischium and pubis. See also Table 10.

pelvic canal

the canal from the pelvic inlet to the pelvic outlet.

pelvic cavity

the space bounded by the bones of the pelvis.

pelvic girdle

the bony ring formed by the pair of hip bones fused at the symphysis and their firm articulation with the sacrum, and in some species one or two coccygeal vertebrae.

pelvic inlet

the cranial opening of the pelvis.

pelvic intestinal hernia

see pelvic hernia.

pelvic ligaments

include the dorsal sacroiliac, the sacrotuberal and the iliolumbar ligaments.

pelvic limb

the hindlimb.

pelvic nerve

see Table 14.

pelvic organs

includes reproductive organs, urinary bladder, ureter, rectum.

pelvic outlet

the caudal opening of the pelvis, guarded by the pelvic diaphragm.

pelvic plexus

the autonomic plexus that is distributed to the pelvic viscera that consists of the cranial vesical plexus, the middle genital plexus and the caudal hemorrhoidal plexus, located on the ventrolateral surface of the rectum. It innervates the urinary bladder, prostate, ductus deferens and cranial urethra. It is supplied by the hypogastric and pelvic splanchnic nerves.

pelvic splanchnic nerves

see nervi erigentes.

pelvic symphysiotomy

surgical separation of the symphysis in immature animals as an aid in dystocia due to maternal pelvic inadequacy.

pelvic urethra

that part of the urethra that passes through the pelvis.

pelvic viscera

includes urinary bladder and pelvic ureters and urethra, rectum, prostate, seminal vesicles, vas deferens and ampullae in males, and vagina cervix and uterus, possibly ovaries, in the female.

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pelvic inlet

apertura pelvis superior, pelvic brim Anatomy The upper opening of the minor pelvis, bounded by the crest and pecten of pubic bones, ilia arcuate lines, and anterior sacrum. Cf Pelvic outlet.