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Flashcards in perineum Deck (14):

name the structures that line the pelvic outlet

- pubic symphysis
- ischiopubic ramus
- ischial tuberosity
- ST ligament
- coccyx


what are the two triangles within the pelvic outlet

- urogenital triangle

- anal triangle


describe the function and location of the perineal body

anchor point for many muscles, it is composed of fibrous connective tissue
found between the urogenital and anal triangle


describe the levator ani and its divisions

the pelvic floor muscle (funnel shape)

3 main divisions:
- ischiococcygeus
- iliococcygeus
- pubococcygeus


what is the nerve supply to the levator ani

pudendal nerve (S2-4)
nerve to levator ani (S3-4)


define puborectalis and how its function can be lost

sling of fiber that come anteriorly to swing around the rectum, creating the anorectal angle (under tonic contraction)
if damage occurs to pudendal or levator ani nerve then loss of function can occur, no control of bowel function


what is the arterial supply and lymphatic drainage to the anal canal

superior rectal artery --> middle rectal --> inferior rectal
pre-aortic --> internal iliac --> superficial inguinal nodes


what is the rectal/anal venous drainage and what is its clinical significance

superior rectal vein anastomosis with inferior rectal vein

portal hypertension can cause ano-rectal varices
hemorrhoids also often occur here


describe the landmarks of the ischioanal fossa

laterally = ischial tuberosity

posteriorly = coccyx

midline = perineal body

(avoid lateral apex = pudendal vessels)


why is there more muscle in the deep perineal pouch of a female compared to a male

short vertical course of the urethra, therefore additional muscles to help control flow of urine


what artery supplies the perineum

internal pudendal artery


what are the main branches of the internal pudendal artery

- inferior rectal
- perineal
- dorsal artery of penis/clitoris

(same for nerves of pudendal)


what is the main nerve supply to the perineum

pudendal nerve S2-4


what occurs for defaecation to be carried out?

- relaxation of puborectalis
- relaxation of internal and external sphincters
- parasympathetic contraction of pelvic muscles
- increased intra-abdominal pressure