GA-Bony Pelvis and the Pelvic wall Flashcards
What level is the pelvic inlet?
level of sacral promontory
what bone bears abdominal weight?
pubic bone
What is the correct anatomical position of the pelvis?
ASIS and anterior pubis are in the same vertical plane
What is the function of the sacroiliac ligaments? which one is thicker?
hold sacrum in place like a wedge between the two hip bones, posterior is thicker
what ligaments prevent the pelvis/coccyx/sacrum from rotating too far anteriorly?
sacrotuberous and sacrospinous ligament
What are the boundaries of the lesser pelvis? (true pelvis) what spinal level does it start?
superior-pelvic inlet
inferior-pelvic diaphragm
lateral-hip bones (all three)
posterior-sacrum/coccyx
L5-S1
what are the boundaries of the greater pelvis? what does it contain?
superior to pelvic brim within the pelvic bones
holds abdominal viscera
what passes through the levator hiatus? what are its boundaries?
ureter, rectum, vagina (in females)
boundaries-pubococcygeal, and puborectalis form anterior/medial fibers
what are the boundaries of the ischiorectal fossa? what are its contents? what is its function?
inferior-perineal membrane-strong membrane between pubic rami
superior-pelvic floor muscle
contents-fat filled diamond shaped, anorectal and urogenital parts
function: allows movement of pelvic diaphragm and expansion of anal canal for pooing
what muscles make up the pelvic wall?
obturator internus
piriformis
coccygeus
what is the innervation and function of the obturator internus?
obturator nerve
lateral rotation of thigh, support pelvic wall
what is the innervation and function of the piriformis?
innvervation: nerve to piriformis
function-lateral rotation of thigh, support wall
what is the innervation and function of the coccygeus m?
innervation: anterior rami of S4-S5
function: support pelvic viscera, flex coccyx
what muscles make up the pelvic floor? what is the function of the pelvic floor?
levator ani and ischiococcygeus, to support viscera and control tone of anus
what muscles make up the levator ani muscle?
pubococcygeus
puborectalis
iliococcygeus
what is significant about the puborectalis muscle?
helps form the anorectal angle and maintains fecal continence
-relaxes during defication and relaxes when you squat so you can poo easier
what makes up the tendinous arch of the levator ani?
thickening of obturator fascia between ischial spine and body of pubis
what spinal level is the rectosigmoid junction?
S3
which anal sphincter contributes the greatest to resting anal tone? is it voluntary or involuntary?
internal, involuntary smooth muscle
what nerve innervates above/below the pectinate line?
above: inferior hypogastric n (visceral)
below: inferior rectal nerves (somatic)
what veins drain above/below the pectinate line? what type of circulation are they
above: superior rectal vein (portal circulation)
below: inferior rectal veins (systemic)
what type of hemorrhoid is painful? why?
external hemorrhoids, they receive somatic innervation so they are painful, internal receive visceral
what is the difference between internal and external hemorrhoids?
external are painful and covered in epidermis from the ectoderm
internal are not painful and covered in muscularis mucosa and are from endoderm
oh no! you get in a car crash and it crushed your pelvis with an anteroposterior compression force! what is broken? what is a consequence of this break?
fracture of all 4 pubic rami
pelvic instability and genitourinary injury
what breaks with lateral compression of the pelvis?
ilia and acetabulums
if you jump off a building and land on your feet with your legs straight whats gonna break?
head of femur will dislocate through the acetabulum into the pelvic viscera
What are the weak areas of the pelvis?
pubic rami, acetabilum, sacroiliac joints
what is the difference between a male and female pelvis?
male has:
smaller pelvic outlet
narrower pubic arch (<70 degrees, female >80)
round obturator foramen (females is oval)
greater sciatic notch is the angle of a V female is 90 degrees
what muscles are most susceptible to tearing during childbirth? why?
puborectalis and pubococcygeus
they are the most medial and large part of the levator ani
