Perineum Male and Female

Question 1

perineum boundaries

general

Answer 1

pubic symphisis
R and L IT’s
coccyx

diamond shape
divide in half for urogenital triangle and anal triangle

Question 2

anal canal

Answer 2

pectinate line where endo and exoderm meet
-above line = endoderm feel stretch, pressure
-below line = exoderm, feel pain

anorectal juction in ampulla

Question 3

anal sphincters

Answer 3

internal = involuntary
external = voluntary

Question 4

external sphincter divisions

Answer 4

subcutaneous
superficial
deep (continuos w/ levator ani)

inn: inferior rectal N

Question 5

levator ani

Answer 5

muscle that holds pelvic bowl contents in place

Question 6

ishioanal fossa

Answer 6

fat filled triangle for packing levator ani in place

bound by levator ani (medial) + obturator internus (lateral) + skin (inferior)

Question 7

pudendal canal

aka Alcock’s

Answer 7

contains pudendal nerve + internal pudendal artery + internal pudendal vein

aka nerve of shame

Question 8

scrotum

Answer 8

testes
epididymsis
part of spermatic cord

Question 9

penis -root

Answer 9

physically attached to body

has bulb w/ R and L crus on either side, all erectile tissue

Question 10

penis - body

Answer 10

continuation from root
1. corpus spongiosum- from bulb, has urethra, expands to glans
2. corpora cavernosa- from R and L crura, bounded by deep penile fascia

Question 11

internal urethral sphincter

Answer 11

distal side of bladder/proximal side of prostate aka b/t bladder and prostate

prevents retrograde ejaculation aka no semen in the bladder

Question 12

anal canal arteries

Answer 12

collateral circulation from hindgut and internal iliac arteries

middle and inferior rectal a.s (from internal iliac) anastomose w/ superior rectal from IMA

Question 13

anal canal veins

Answer 13

inferior mesenteric vein and superior rectal > hepatic portal

middle rectal and inferior rectal > IVC

Question 14

prostatic plexus

Answer 14

parasympathetic nerves S2-4
somatic also

surrounds prostate
responsible for erection

Question 15

superficial perineal pouch

both

Answer 15

1. bulbospongiosus (covers bulb)
   -tightens to keep blood in erect
   -cleans urethra before and during ejaculation
   -can weakly contract vagina
2. ischiocavernosus (covers crura)
   -keep blood in during erection
3. perineal body - CT that holds entire perineum together
   -shorter b/t vagina and anus for females
4. superficial transverse perineals- keep pelvic floor taught

all innervated by nerineal nerve from pudendal

Question 16

perineal nerve

both

Answer 16

from pudendal

motor to:
bulbospongiosus
ischiocavernosus
levator ani
superficial and deep transverse perineal
external urethral sphincter

sensory to:
posterior skin of scrotum OR
skin of labia majora/minora

Question 17

deep pouch

male

Answer 17

1. membranous/intermediate urethra
   (shortest of the 3 parts)
2. external urethral sphincter/sphincter urethrae @ below prostate
3. bulbourethral/cowpers glands- cleans urethra of residues, duct to penile urethra

Question 18

deep pouch innervation

both

Answer 18

dorsal nerve of penis or clitoris

sensory:
skin of penis or clitoris
responsible for sensory orgasm

sensory is the main type for females

Question 19

deep pouch blood supply

Answer 19

from internal pudendal artery

1. dorsal a. of penis to corpus spongiosum
2. deep a. of penis to corpora cavernosa

need both for full erection but mainly deep A

same for female just clitoris

Question 20

erection steps

Answer 20

1. parasympathetic stimulation by cavernous nerves (S2-4) shuts down anastomoses
2. smooth muscle in coiled arteries relaxes > helicine arteries straighten = cavernous sinuses fill w/ blood
3. bulbospongiosus and ischiocavernosus contract = block off deep dorsal vein so sinuses can’t drain, somatic

Question 21

emission steps

Answer 21

1. semen delivered to prostatic urethra thru ejaculatory ducts and seminal vesicles, prostatic fluid added

sympathetic response aka L1-2

Question 22

ejaculation steps

Answer 22

1. internal urethral sphincter closes so no retrograde ejaculation sympathetic L1-2
2. urethral muscle contracts parasymp S2-4
3. bulbospongiosus muscles contract somatic S2-4

Question 23

remission steps

Answer 23

1. penis return to flacid state from sympathetic resp = constriction of smooth muscle in helicine arteries
2. bulbospongiosus and ischiocavernosus relax = blood drains back into deep dorsal vein somatic

Question 24

erection process

general

Answer 24

1. erection
2. emission
3. ejaculation
4. remission

Question 25

prostate surgery | clinical correlate

Answer 25

damage to prostatic plexus (leads to cavernous nerves of penis aka resp for erection) so impotence treat w/ prosthesis semirigid or inflatable NOT viagra bc problem is not arterial

Question 26

UG triangle | female

Answer 26

aka vulva prepuce covers clitoris frenulum labium majus and minus vestibule aka vagina

Question 27

clitoris

Answer 27

R and L crus/crura w/ erectile tissue > body > glans bulb of vestibule of erectile tissue to maintain clitoral erection | no corpus spongiosum, bulb instead

Question 28

superficial pouch | female

Answer 28

crus bulb of the vestibule paraurethral gland/lesser vestibular- prostate in men, no specific known function in female but maybe g spot? greater vestibular gland- lubricate vaginal opening

Question 29

deep pouch | female

Answer 29

urethra sphincter urethrae/external vagina perineal membrane over deep transverse perineal muscle females have internal sphincter but weaker than male and doesn't usually work

Question 30

dorsal nerve of clitoris | clinical correlate

Answer 30

cut or damanged w/ episiotomy, cancer removal, labioplasty no orgasms

Question 31

perineal body damage

Answer 31

uterine prolapse childbirth- if baby head/shoulders too big then tear or destroy why?? bc multiple muscles attachment point

Question 32

uterine prolapse types

Answer 32

1st degree- slight descent, uterus just slips down 2nd degree- cervix at entrance of vagina 4th degree- complete prolapse, exit the body, no control over urinary bladder

Question 33

prolapse treatments

Answer 33

1. PT is best to strengthen muscles 2. gellhorn pessary, only temporary, holds uterus up, can be removed to clean 3. surgery to hold up uterus if no more kids

Question 34

episiotomy

Answer 34

only done if 1. baby's shoulder is stuck behind pelvic bone (shoulder dystocia) 2. baby has abnormal heart rate in delivery 3. operative vaginal delivery w/ forceps or vacuum either midline or mediolateral incision | doesn't actually prevent tearing but does heal cleaner

Question 35

chronic perineal injury | males

Answer 35

from bicycle seats, motorcycles, horse back riding, constipation = urinary incontinence, bowel incontinence, ED can also be acute from trauma

Question 36

pelvis and perineum SOMATICS | both-sensory

Answer 36

-voluntary control SOMATICS -pudendal nerve S2-4 -external sphincters prevent leakage w/ stress, strain, sleep -tonically active so inhibition = relax -sensory from external anal and urethral sphincters, pelvic floor muscles, anal canal, urethra aka will let you know when bladder infection

Question 37

pelvis and perineum SYMPATHETICS | both-sensory

Answer 37

involuntary T11-L2 -contract internal anal sphincter and urethral for males -contract ductus deferens, seminal vesicles, prostatic muslces during emission and remission -poorly localized sensory but most sensitive to distension

Question 38

pelvis and perineum PARASYMPATHETICS | both-sensory

Answer 38

-involuntary -S2-4 (same as somatic) -smooth muscle in organ walls -begins erection to relax helicine arteries -contract urethral muscle during ejaculation -contracts detrusor/bladder and rectal muscles -conveys normal sensation of bladder and rectal distension