201- Pelvic anatomy Flashcards
what composes pelvis
L and R innominate bone (illim, ischium, pubis) and the sacrum
components of pelvic brim (inlet of birth canal separating false (major) pelvis from true (minor) pelvis
pubic tubercles and crest, pecten pubis, arcutate line of ilium, ala of sacrum and sacral promontory
why does the infants head rotate during birth
as it tries to get through the narrowest part of the pelvic outlet (b/w the ischial spines)
function of sacrospinous and sacrotuberous ligaments
Reinforces sacroiliac synovial joint. Resists anterior rotation of sacrum
female pelvic diaphragm mm.? Where do they originate and insert?
Levator ani (pubococcygeus + iliococcygeus) and ischiococcygeus (since it is bone to bone it doesnt elevate the anus). Originate BELOW pelvic brin on lower pelvic wall. Go posteriorly to central tendon of perineum (perineal body) and anococcygeal ligament
What is the pubo-rectal sling and its purpose
the puborectalis (most medial part of pubococygeus). Constant tone bends rectum but relaxation on defecation straightens it.
result of weak pubococcygeus
uterine prolapse
which pelvic organs are retroperitoneal and which are not?
Retro: bladder, vag, rectum.
Have mesenteries: uterus and sigmoid colon
innervation of bladder
Trigone supplied by sympathetics, parasympathetics cause wall contraction
common sites of kidney stones to logde
renal pelvis, common iliac vessels, entrance to bladder
cloacal membrane
sits at the pectinate line at he bottom of anal columns. Where endoderm meets ectoderm
venous drainage around pectinate line
above: superior rectal veins drain into portal system.
Below: drain into ilial/caval system
innervation of hemorrhoids
internal: visceral sensory (no pain). External: general sensory (intense pain, itching)
innervation of mm. around pectinate line
above: pelvic splanchnic (autonomic) from pelvic plexus (S2,3,4)
Below: pudendal (skeletal)
