Pelvis Flashcards
Which is the true pelvis and which is the false?
- True: pelvis minor, inferior to superior pelvic aperture
- False: pelvis major, b/w the iliac fossae
What ligament spans from iliac to sacral tuberosities?
Sacroiliac ligament
What vertebra sits above the sacrum?
L5
What ligament spans from L5 to iliac crest? (not on test)
Iliolumbar ligament
What ligament spans from the lateral sacrum/coccyx to the ischial tuberosity?
Sacrotuberous ligament
What ligament spans from the sacrum to the ischial spine?
Sacrospinous ligament
What hole is formed above the sacrotuberous ligament?
Greater sciatic foramen
What hole is formed b/w the sacrotuberous and sacrospinous ligaments?
Lesser sciatic foramen
Obturator internus m: OIIA?
O: Inner surface of obturator membrane
I: Greater trochanter of femur
I: Nerve to obturator internus
A: Laterally rotates and stabilizes hip
Piriformis m: OIIA?
O: Anterior surface of sacrum
I: Greater trochanter of femur
I: Nerve to piriformis (ant rami S1, S2)
A: Laterally rotates and stabilizes hip, abducts thigh
What 2 mm. make up the floor of the pelvic diaphragm?
- Levator ani mm.
- Coccygeus m.
What are the 2 mm. of the levator ani mm?
- Iliococcygeus m.
- Pubococcygeus m.
What is the pelvic fascia continuous with?
Transversalis fascia
Coccygeus m: OIIA?
O: Sacrospinous ligament
I: Coccyx
I: Ant rami S4, S5 (nerve to coccygeus?)
A: Supports pelvic viscera
What is the term for the white line in the pelvic fascia over the obturator foramen?
What attaches onto this line?
- Arcus tendineus
- Levator ani mm.
What m. lies right next to the sacrospinous ligament?
Coccygeus m.
Levator ani mm: OIIA?
O: Tendineus arch, body of pubis, ischial spine
I: Perineal body, coccyx, anococcygeal raphe, walls of prostate or vagina, rectum, anal canal
I: Ventral rami of lower sacral nerves, perineal n.
A: Supports pelvic viscera, raises pelvic floor
What is the function of the urogenital diaphragm?
Provides a solid support for the pelvic viscera
What is the general supply of the anterior division of the internal iliac a? What about for the posterior division?
- Ant: Supplies most of the blood to the pelvis
- Post: All are muscular branches
What are the branches of the anterior division of the internal iliac artery?
“Um, obviously I value my really insanely good iced popsicle”
- Umbilical a., gives branch to superior vesicle a.
- Obturator a.
- Inferior vesicle a.
- Middle rectal a.
- Inferior gluteal a.
- Internal pudendal a.
What are the branches of the posterior division of the internal iliac artery?
“I love sugar”
- Iliolumbar a.
- Lateral sacral a.
- Superior gluteal a.
What is the branch of the umbilical a?
Superior vesicle a.
In females, the vaginal a. and uterine a. can replace which a.?
Inferior vesicle a.
What m. is the dividing line for the name of the superior and inferior gluteal aa., among others?
Piriformis m.
What a. goes through the obturator foramen?
Obturator a., v., n.
What a. goes through the holes in the sacrum?
Lateral sacral a.
What does the sacral plexus span from?
L4-S5
- Ventral rami os S1-S4
- Receives L4-L5 from lumbosacral trunk
What m. does the sacral plexus rest on?
Piriformis m.
What is the ganglion impar?
Where the 2 pelvic sympathetic trunks converge (near tip of coccyx)
What are the nerve root contributions for the sciatic n?
L4, L5, S1, S2, S3
What are the nerve root contributions for the femoral n?
L2, L3, L4 (keeps the foot off the floor)
What are the nerve root contributions for the pudendal n?
S2, S3, S4 (keeps the junk off the floor)
What are the 2 portions of the sciatic n?
- Common peroneal portion
- Tibial portion
Where does the rectum end?
Ano-rectal junction
Where is the vesicouterine pouch??
B/w the bladder and uterus, females only
Where is the rectouterine pouch?
What’s another name for it?
- B/w the rectum and uterus, female only
AKA Cul-de-sac of Douglas
What is the rectal ampulla?
Terminal dilated part of rectum
Where is the rectovesicle pouch?
B/w rectum and bladder, males only
What marks the transition from the rectum to the anal canal, caudal to the ano-rectal junction?
Pectinate line
What sensation is above and below the pectinate line?
What is the pattern of lymph drainage above and below the line?
- GVA above (deeper sensation). Lymph drainage is internal
- SVA below (sharp, localized). Lymph drainage superficial
What aa. supply the rectum?
- Superior rectal a. (upper 2/3++)
- Middle rectal a. (lower 1/3, muscular)
- Inferior rectal a. (anasotmoses w/sup rectal in anal columns)
Where did the superior rectal a. branch from?
IMA
Where did the middle rectal a. branch from?
Internal iliac a., anterior division
Where did the inferior rectal a. branch from?
Internal pudendal a.
Which circuits are the rectal vv. off of?
Superior rectal v: portal system (liver, so cirrhosis can lead to hemorrhoids)
Middle and inferior rectal vv: somatic circuits
Which anal sphincter is voluntary vs. involuntary?
Internal: involuntary
External: voluntary
What m. is in the wall of the bladder?
Detrusor m.
What aa. supply the bladder?
- Superior vesicle a. (ant division; off umbilical a.)
- Inferior vesicle a. (ant division; sometimes replaced by vaginal and uterine aa. in females)
What is the name of the smooth triangular region of the bladder?
Trigone
Why are females more prone to UTI?
Urethra is only ~1.5” long
What are the main parts of the male urethra?
- Prostatic urethra
- Membranous urethra
- Spongy urethra
Where do the ductus deferens and seminal vesicles merge to enter the prostatic urethra?
Ejaculator duct
What is the prostatic utricle?
Small, epithelium-lined diverticulum in the prostatic urethra
- homologue of female vagina
The umbilical a. gives a branch to what a.?
Superior vesicle a.
Piriformis m. comes out of which foramen?
Obturator internus m. comes out of which foramen?
- Greater sciatic foramen
- Lesser sciatic foramen
Where does the sciatic n. exit the pelvis?
Greater sciatic foramen, above the sacrospinous ligament, and goes out below the piriformis m.
What is the course of the pudendal n. in the pelvis?
Goes in greater sciatic foramen and out the lesser sciatic foramen, coursing over the sacrospinous ligament. Then goes through alcock’s (pudendal) canal.
