Flashcards in Pelvis (its Contents & the Floor) Deck (36):
What makes up the "false" (greater) pelvis?
- the part between the iliac crests and the pelvic inlet
What makes up the "true" (lesser) pelvis?
- the basin-shaped cavity below the pelvic inlet
Which bones make up the pelvis?
- the sacrum and the hip bones on each side
Which three bones make up each hip bone?
- pubis, ilium, and ischium
What is the large foramen in each hip bone called?
- the obturator foramen
What converts the greater and lesser sciatic notches into the greater and lesser sciatic foramina?
- the sacrospinous and sacrotuberous ligaments
What is the small opening in the obturator membrane called?
- the obturator canal
Is the sub-pubic angle greater in males or in females?
- it is V-shaped in males and U-shaped in females
Describe the shape of the obturator foramen in males and females.
- the foramen tends to be circular in males, and more oval in females
T or F: the acetabulum is generally larger in females.
- it is larger in males
What makes up the pelvic floor?
- the pelvic diaphragm and the urogenital diaphragm
What makes up the pelvic diaphragm?
- the levator ani ani the coccygeus muscles (along with the fascia above and below them)
What are the three parts of the levator ani muscle?
- the puborectalis
- the pubococcygeus
- the iliococcygeus
Where is the perineum located?
- below the pelvic diaphragm
What makes up the urogenital diaphragm?
- the deep and superficial transverse perineal muscles
T or F: the urethra pierces the urogenital diaphragm, but the anal canal does not.
- this is because the urogenital diaphragm is present only in the anterior part of the pelvic outlet, not the posterior
Which two muscles lie below the urogenital diaphragm?
- the isciocavernosus muscles and the bulbospongiosus
Where is the pudendal canal (Alcock's Canal)? What does it contain?
- on the lateral side of each ischiorectal/ischioanal fossa
- the pudendal nerve and internal pudendal vessels
Does the vagina pierce through the pelvic diaphragm? What about the urogenital diaphragm?
- it pierces through both!
- as does the urethra
Does the male urethra pierce through the pelvic diaphragm? What about the urogenital diaphragm?
- it pierces through both
Does the anal canal pierce through the pelvic diaphragm? What about the urogenital diaphragm?
- the anal canal pierces through only the pelvic diaphragm
At what point does the rectum become the anal canal?
- at the anorectal junction
Which part of the levator ani is involved in defecation?
- the puborectalis muscle
In males, what is the space/pouch of the peritoneal cavity between the rectum and the bladder known as? What about in females?
- males: rectovesical pouch
- females: rectouterine pouch (pouch of Douglas), because the uterus is located here
The "grooved" portion inside the anal canal that separates the rectum from the anus is known as the:
- pectinate line
- it "separates" the visceral from the parietal
What does each anal column (the anal columns make up the pectinate line) contain?
- a small artery and vein
- this is where hemorrhoids can form
Lymphatic drainage above the pectinate line mainly goes to which nodes?
- the internal iliac nodes or the nodes near the inferior mesenteric vessels
Lymphatic drainage below the pectinate line mainly goes to which nodes?
- the inguinal nodes
The internal anal sphincter is made up of _________; the external sphincter is made up of __________.
- internal: smooth muscle
- external: skeletal muscle
Which 4 arteries supply the lower rectum and the anal canal? Where do they originate from?
- superior rectal arteries (from the inferior mesenteric)
- middle rectal arteries (from the internal iliac)
- inferior rectal arteries (from the internal pudendal)
- median sacral artery
What is the main arterial supply to the pelvis and its organs?
- the internal iliac arteries and its branches
What are the two main branches of the internal iliac artery?
- the posterior division and the anterior division
Which arterial branches arise from the posterior division of the internal iliac?
- iliolumbar, lateral sacral, and superior gluteal
Which arterial branches arise from the anterior division of the internal iliac?
- umbilical, superior & inferior vesical, obturator, middle rectal, uterine & vaginal, internal pudendal, and inferior gluteal
T or F: the entire pelvic diaphragm is normally in a tonic/contracted state.
- they are in this contracted state via slow twitch muscle fibers