Perineum

Question 1

What are the pelvic outlet boundaries?

Answer 1

Ps, ischiopubic rami, ischial tuberosity, St lig and coccyx

Question 2

What is the perineal body?

Answer 2

fibrous CT where a lot of muscles connect eh

Levator ani, bulbospongiosus, external anal sphincter, perineal muscles

Question 3

What forms the ppelvic diaphragm?

Answer 3

levator ani and coccygeus

Question 4

What are the three main divisions of levator ani?

important division of pubococcygeus

Answer 4

ischiococcygeus; iliococcygeus; pubococcygeus

puborectalis wraps aound rectum to form U bend. (also pubo vaginalis/ levator prostatae)

Question 5

What can be said iliococygeus/

Answer 5

attaches to obturator intenrus fascia and prevents prolapse of pelvic viscera

Question 6

External anal spincter

Answer 6

skeletal muscle, perineal body to anococcygeal lig

Pudendal nerve inf rectal branch

Question 7

What are the landmarks of the ischioanal fossa?

Answer 7

ischial tuberosity(laterally); coccyx (post); perineal body in midline
avoid lateral apex, as pudendal nerves and internal pudendal artery runs here

Question 8

When rectum pierces ____ it becomes anal canal?

Answer 8

pelvic floor
diagram page 114
note that anal columns contain superior rectal vessels

Question 9

arterial supply and lymphatics of rectum

venous drainage

Answer 9

Sup. rectal (inf mesenteric). Pre-aortic nodes at L3
Middle rectal: int iliac, II nodes
Inf rectal, from internal pudendal. II nodes
anal canal to superficial inguinal nodes

Anastomosis of sup rectal vein and inf rectal vein. Site of haemorrhoids. (portal systemic)

Question 10

What comprises the urogenital diaphragm?

Answer 10

Deep/superior: fascia that blends with perineal body/membrane
Middle: sphincter urethrae, deep transverse perineal muscles
Superfical/inferior: perineal membrane, superficial fascia

Note that it is attached to the ischiopubic rami and perineal body

Question 11

What is in the deep perineal pouch? *** (weird)

Answer 11

is all structures deep to the perineal membrane so the muscles etc ( external urethral sphincters and deep transverse perineal)
Males- membranous urethra; bulbourethral glands; NV stuff so dorsal nerves and arteries of penis
Females- vagina; compresor urethrae; dorsal nerves and arteries of clitoris

Question 12

What is in the superficial perineal pouch?

Answer 12

structures between perineal membrane and skin

-nerves and vessels; perineal muscles; erectile tissues; bartholins glands (females)

Question 13

What is important about fascia in the superficial pouch?

Answer 13

Scarpas fascia is continuous with dartos (penis and scrotum) and colles (perineum) fascia.
So if trauma occurs, bleeding into superficial pouch can end up in the abdomen

Question 14

What are the three branches of the internal pudendal artery we must know?

Answer 14

Inferior rectal
perineal
dorsal artery of penis/clitoris
(inf rectal first then split between the other two)

Question 15

What does the pudendal nerve supply? (S2-4)

branches?

Answer 15

perineal muscles
External urethral sphincter
skin of genitalia and perineum
erectile muscles (ischiocavernosus and bulbospongiosus)

branches are same as artery

Question 16

What happens with dermatomes if damage to pudendal nerve/ cauda equina compression?

Answer 16

Saddle anaesthesia. NB dermatome to anus is S5 so don’t prick it

Question 17

What is an episiotomy?

Answer 17

Surgical incision of the perineum to facilitate childbirth

normally medio lateral/ midline. Local anaesthetic to pudendal nerve is done