GA-Perineum Flashcards
what are the boundaries of the perineum? a/p/l
lateral-ischiopubic rami and sacrotuberous ligaments
anterior-pubic symphesis
posterior-coccyx
what are the boundaries of the urogenital triangle?
pubic symphysis
ischiopubic rami
imaginary line between ischial tuberosities
what are the boundaries of the anal triangle?
coccyx
sacrotuberous ligaments
imaginary line between ischial tuberosities
what are the contents of the ischioanal fossa?
- fat
- anal canal
- external opening of anus w/sphincters
- pudendal canals (with internal pudendal a and pudendal nerve
what is the ischioanal fossa?
the contents of the anal triangle
what are the boundaries of the ischioanal fossa? superior, inferior, lateral
superiormedial-levatori ani and anal canal
inferior-skin of perineum
latreal-obturator internus
what is the function of the ischioanal fossa?
allows for distention of the anal canal during defication
no vital organs near to interfere
what are the contents of the urogenital triangle?
superficial and deep perineal pouches
what is contained in the deep perineal pouch of the urogenital triangle? 3
membranous urethra in males, first part of urethra in females
bulbourethral glands
deep perineal muscles
what are the deep perineal muscles?
external urethral sphincter
deep transverse perineus
what is the contained in the superficial perineal pouch?
the male and female external genetalia
where is the pudendal canal located?
lateral to the ischorectal fossa in the anal triangle on medial surface of obturator internus
what are the contents of the pudendal canal?
pudendal n
internal pudendal a/v
inferior rectal a/v
what is the pathway of the pudendal nerve?
S2-S4 –> greater sciatic foramen –> lesser sciatic foramen –> pudendal canal –> innervates everything that internal pudendal a supplies
what are the sensory/motor functions of the pudendal nerve? 4
preganglionic parasympathetic (GVE)--> glands/sm postganglionic sympathetic (GVE) --> glands/sm somatic motor (GSE) --> skeletal m somatic sensory (GSA) --> perinum skin, distal anal canal, distal vagina
what is the pathway of the internal pudendal a.
anterior branch of internal iliac –> greater sciatic foramen –> lesser sciatic foramen –> pudendal canal –> branches to inferior anal canal, ischiorectal fossa, deep/superficial perineal space, helicine arteries –> supply erectile tissue
what does the internal pudendal a supply? 4
inferior anal canal
ischiorectal fossa
deep/superficial perineal fossa
helicine arteries –> supply erectile tissues and dorsal arteries of penis and clit
what innervates the internal anal sphincter?
pelvic splanchnic nerves (involuntary)
what innervates the external anal sphincter?
inferior anal branch of pudendal nerve
what structures are at the root of the penis?
left and right crura
ischiocavernosis muscle
bulbospongiosus muscle
what is the function of the ischiocavernosus muscle?
compress the vein that drains corpus cavernosa causing erection (parasympathetic)
what is the function of the bulbospongiosus muscle?
compresses urethra to empty it of semen and urine
what is the organization of the shaft of the penis?
3 bodies of erectile tissue
bilateral corpus cavernosa
corpus spongiosum
surrounded by bucks fascia
what makes up the femle external genitalia?
labia majora
labia minora
vestibule
clitoris
what do the labia majora unite to form?
mons pubis
what do the labia minora do?
surround vestibule
what does the vestibule contain?
paraurethral glands
greater vestibular glands
external urethral oriphace
what makes up the clitoris?
two crura and two corpus cavernosum that combine to form one glans clitoris
ischiocavernosus muscle also contracts to cause lady boner
what is the function/location of the bulbs of vestibule in females?
just deep to vestible and is composed of erectile tissue covered in bulbocavernosus muscle that inhibits venous return
what is the function of the greater vestibular glands?
makes a lady moist during sex
what can cause impotence in males?
athlerosclerosis in the internal pudendal a.
diabetic neuropathy/prostate removal damaging the pudendal nerve
what is cut in an episiotomy? why is this done? what is most common cut?
skin, bulbospongiosus, superficial transverse perineal muscle, posterior vaginal wall
to enlarge the vaginal canal thats going to tear anyways cause its easier to repair if cut
mediolateral cut
