Flashcards in Extra Pelvis/perineum cards Deck (66)
Levator ani complex- O, I, In
O- (laterally/peripherally) attaches to pubic bone body, tendinous arch of obturator internus + ischial spine
I- (centrally) vag wall/prostate, perineal body, rectum/anus junction + anococcygeal ligament
In- levator ani (S4) + inferior anal nerve
obturator internus- O, I, Axn, In
O- pubis/ischium + obturator membrane
Axn- lateral rotator of thigh
In- nerve to obturator internus (L5-S2)
Coccygeus- O, I, Axn, In
O- anterior sacrum + coccyx
Axn-supports pelvic viscera, flexes coccyx
In-ventral rami S4 + S5
piriformis- O, I, Axn, In
O- anterior sacrum
Axn- lateral rotator of thigh
In- ventral rami S1 +S2
which muscles attach to the anterior sacrum?
coccygeus and piriformis
which two muscles are lateral rotators of the thigh?
piriformis and obterator internus
what is the narrowest FIXED diameter of the pelvis?
AP diameter, obstetric/true conujate
what is the narrowest non-fixed diameter of the pelvis
interspinous distance (between ischial spines)
how is the obstetric/true diameter estimated?
take the diagonal conjugate (BOTTOM of pubic symphysis to the sacral promontory) and subtract 1cm
where is the endopelvic fascia?
fills potential spaces - prevesical + retrorectal, paravesicular and retrouterine.
Denser condensations of it form ligaments
where is the hypogastric sheath? what does it allow passage of?
separates pre/para vesical spaces and retrorectal spaces
-passage of structures (neurovasc, ureters, vas defrens) from lateral pelvic wall to viscera?
what makes up the pelvic floor/diaphragm? (medial to lateral)
levator ani- puborectalis, pubococcygeus, ileococcygeus
(extends to membrane obterator internus laterally) coccygeus (most posterior)
borders of the pelvic wall: anterior
what does it support?
pubic symphysis, bodies and rami.
-supports weight of bladder
borders of pelvic wall: lateral
body of ilium + ischium
obterator foramen (covered by membrane of Ob internus)
borders of pelvic wall: posterior
sacrum and coccyx, sacrospinous + sacrotuberous ligaments, piriformis
what are the only truly intraperitoneal elements of the pelvis?
uterine tubes (with ovary)
what does the pelvic inlet (superior pelvic aperature) divide?
greater and lesser pelvis
landmarks of pelvic inlet (superior pelvic aperature)
all defined by pelvic brim: sacral promontory
linea terminalis: arcuate line, pectin pubis, pubic crest
what is the other name for the superior pelvic aperature? where are the anterior and posterior landmarks?
pelvic inlet: diagonal line..
anterior- upper pubi symphysis
posterior: sacral promontory
what is the other name for the inferior pelvic aperature? what are the anterior and posterior landmarks?
pelvic outlet: horizontal line
anterior- pubic arch (under pubic symphysis)
what does the pelvic outlet/inferior pelvic aperature divide?
lesser pelvis and perineum
landmarks of the borders of the pelvic outlet/inferior pelvic aperature?
pubic arch of ischiopubic rami
tip of coccyx
where are the pubic tubercles?
anterior surface on either side of pubic symphysis
-bumps pushing out from just along/under pubic crest
where does the common iliac "bifurcate"?
what does the internal iliac descend toward?
where is the ureter in relation to this?
-internal iliac descends toward GSF
-ureter crosses anterior to bifurcation
what vertebral level is the rectosigmoid jxn?
what is the anatomical change here that shows this change?
-convergence of tenia coli (to form continuous longitudinal muscle)
-absence of epilpoic appendages
what is the rectum supported by in the lesser pelvis?
laterally- lateral rectal ligament
what are the two main groups of the 5 flexures of the rectum?
what are the 2 anteroposterior flexures of the rectum?
sacral (sacrum/coccyx contour)
anorectal (@ pelvic diaphragm) - 80 degrees formed by puborectalis muscle
what are the 3 lateral flexures of the rectum?
"transverse folds/ valves of houston"