Walls and Floor of Pelvis Flashcards
What divides the greater and lesser sciatic foramen?
sacrospinous and sacrotuberous ligaments
What muscle makes up the side wall of the pelvis?
obturator internus
What muscle makes up the posterior wall of the pelvis?
piriformis
What is the origin and insertion of obturator internus?
originates from the obturator membrane and the surrounding obturator foramen and inserts on to the medial aspect of the greater trochanter
What is the origin and insertion of piriformis?
originates from the middle 3 bodies of the sacrum and the adjacent parts of the lateral mass and inserts on the greater trochanter
What are the three components of the pelvic floor?
pubococcygeus, iliococcygeus and ischiococcygeus
What makes up levator ani?
pubococcygeus and iliococcygeus
What is the origin of the muscles of the pelvic floor?
the internal aspect of the pubic bone, fascial thickening halfway up obturator internus and the ischial spine
What is the insertion of the muscles of the pelvic floor?
midline raphe from the tip of the coccyx to the anorectal junction
What are pubovaginalis, puboprostaticus and puborectalis?
muscular slings formed by the most anterior fibres of pubococcygeus that sling around the midline viscera
What is the action of levator ani?
to elevate the pelvic floor
What is the action of ischiococcygeus?
no function in humans - in animals it wags their tail
What is the anorectal angle?
an angle of 80 degrees that kinks the anorectal juntion - formed by puborectalis - important in fecal continence
What is covered by dense fascia in the pelvis?
things that dont need to expand - walls of the pelvis and rigid structures e.g. prostate
What is covered by loose fascia in the pelvis?
on things that need to expand - levator ani, bladder, anus
What is endopelvic fascia?
the fascia that fills the spaces in the pelvis
Where is the sacral plexus in relation to piriformis and the deep fascia?
the sacral plexus is between piriformis and the deep fascia
Where does the common iliac artery divide?
at the top of the pelvic brim
What does the posterior division of the internal iliac supply?
only has parietal branches - so supplies the walls of the pelvis
What does the anterior division of the internal iliac supply?
has parietal and visceral branches so supplies both the walls of the pelvis and the viscera
What divides the pelvic viscera from the abdominal cavity?
the pelvic peritoneum
What is the vesicouterine pouch?
the pouch created by the fold of pelvic peritoneum between the bladder and the superior anterior part of the uterus
What is the pouch of douglas?
the pouch created by the fold of pelvic peritoneum between the posterior part of the uterus, the posterior superior part of the vagina and the rectum
Why does free fluid collect in the pouch of douglas?
because its the lowest point of the abdomen
