ORG ANA: Perineum Flashcards
refers to the diamond shaped area below the pelvic cavity
perineum
what covers the perineum
levator ani, coccygeus and fascia ng pelvic diaphragm
boundaries of the urogenital
ant - pubic symphysis
lat - ischial tub connect m
boundaries of perineum
ant - pubic symphysis
lat - ischiopubic rami and sarcotub ligaments
post - tip of coccyx
anal triangle boundries
lat - ischial tub and sarcotub ligaments
post - tip of coccyx
divisions of perineum
urogenital - associated w openings of urinary and reproductive
anus - has anus and external anal sphincter
aka central tendon of perineum
perineal body
function of perineal body
attachment of muscles and fascia and is important for stability and integrity
attachment din ng urorectal septum
attachment in perineal body in males
bulb of penis and anus
where is perineal body in females
betw vagina and anus
what is the perineal membrane
anchored in perineal body and pubic arch
sa urogenital lng - supports external genitalia
what is the ischiorectal fossa
located on each side of anal opening - so anus is midline of each side neto
describe the anal canal
1.5 in long - from rectal ampulla to anus
what keeps the lateral wall of anal canal in place
by levator ani and anal sphincter
posterior rela of anal canal
anococcygeal body - fibrous tissue betw anal canal and coccyx
laterally rela of anal canal
ischiorectal fossa
anterior rela of anal canal in males
perineal body, urogenital diaphragm, membranous urethra and bulb
anterior rela of anal canal in females
perineal body, urogenital diaphragm, vagina
function of dentate or pectinate line
divides anal canal into upper and lower
cells of lower anal canal
squamous epithelium
cells of upper anal canal
columnar epithelium
name of vertical folds in upper anal canal
morgagni colums and crypts pag joined by anal valves
how does anal glands work
4-8 anal glands drain into crypts of morgagni at level of pectinate line
nerve supp of upper anal canal
hypogastric plexus - stretch only
blood supp of upper anal canal
superior rectal artery and superior rectal vein
blood supp of lower anal canal
inferior rectal art and vein
nerve supp of lower anal canal
inferior rectal nerve - pain, temp, touch and pressure
describe the muscle coat of anal canal
outer longitudinal and inner circular smooth muscle
compare the internal and external sphincter
internal - involuntary
external - voluntary
what forms the internal sphincter
thickening of smooth muscle of circular coat at upper end of canal
what are the attachments of the external sphincter
subcutaneous - jus under skin
superficial - attaches to the perineal body and coccyx
deep - surrounds the anal canal
what is responsible for the sling of anal canal
puborectalis attached anterior to pubic bone
what forms the anorectal ring
internal sphincter, deep external sphincter and puborectalis
where is the anorectal ring found
at anorectal junction
blood supp of anal sphincter
upper - superior artery
lower - inferior artery
innervation of anal sphincter
upper - hypogastric plexus so stretch
lower - inferior rectal nerve so pain, temp, touch and pressure
nerve supply of internal sphincter
involuntary - sympathetic fibers from inferior hypogastric plexus
nerve supply of external sphincter
voluntary - inferior rectal from pudendal and perineal branch of S4
how does defecation occur
initiated by stretch receptors
coordinated reflex of descending, sigmoid rectum and anal canal
assisted by intra-abdominal pressure from anterior abdominal wall
explain process of defecation
stimulate stretch receptor
rise intra-abdominal psi inhibits contraction of sphincters and puborectalis
mucous membrane of lower anal canal is extruded then returned to anal canal by tone of longitudinal fibers and puborectalis muscle
empty lumen of anal canal is closed by tonic contraction of sphincter
holding phase
puborectalis and sphincters are contracted
initiation phase
puborectalis and sphincters relax
levator ani, diaphragm and abs contract
completion phase
sphincters relax and rectum contracts
wedge shape space of each side of anal canal
ischiorectal fossa or ischioanal
function of ischiorectal fossa
allows movement of pelvic diaphragm and expansion of anal canal in defecation
boundaries of ischiorectal fossa
lateral - ischium
medial - levator ani
contents of ischiorectal fossa
fat which supports anal canal
pudendal nerve and internal pudendal vessel
inferior rectal vessels and nerves
what causes an ischio-anal abcess
mucosa can be torn by hard feces - and infection and inflammation from anal cana can spread to it
ischo-anal abcess that spreads betw sphincters
intersphincteric fistula
what causes internal hemorrhoids
varicosity of superior rectal vein
usually w/in anal canal and can enlarge and extrude in defecation
1st deg internal hemorrhoids
w/in canal
2nd deg internal hemorrhoids
extrude from canal but returns at end of defecation
3rd deg internal hemorrhoids
prolapse and remains outside of anus
what causes external hemorrhoids
varicosities of tributaries inferior rectal vein - sa lower half n ng anal canal
what is anal fissure
elongated ulcer vv painful - from chronic constipation
where is anal fissure common
midline posterior
boundaries of urogenital triangle
pubic arch
ischiopubic rami and ischial rub
connect to ischial tub
layers of urogenital triangle
skin
superficial perineal fascia
deep perineal fascia
superifcial perineal pouch
deep perineal pouch
the superficial fatty layer is aka as
camper’s fascia
the superficial fatty layer is continous w _____
fat of ischioanal fossa and superficial fascia of thigh
the superficial fatty layer becomes ___ at scrotum
dartos muscle
the deep membranous layer is aka as
colle’s structure
the deep membranous layer is attached to ___
posterior perineal body and membrane and laterally to pubic arch
the deep membranous layer is continous w ______
superficial fascia of anterior abdominal wall (scarpas) until penis/clitoris
continous w scrotum or labi majora
loc of superficial perineal pouch
superficial perineal fascia and perineal membrane
desrcibe superficial perineal pouch
closed post by perineal membrane and body
closed lat by membranous layer of superfiscial fascia and perineal membrane of pubic arch
contents of superficial perineal pouch
bulb of penis/vestibule and bulbospongiosus muscle
crura of penis/clit
ischiocavernous muscle
superficial transverse perineal muscle
perineal nerves and vessels
greater vestibular glands - female
loc of deep perineal space
deep to urogenital diaphragm - fills the urogenital hiatus
contents of deep perineal space
urethra
inferior external urethral sphincter
neurovascular branches of
external urethral sphincter
anterior recess of ischioanal fossa
vagina
bulbourethral glands
deep transverse perineal muscle
what makes up the penis
3 masses of erectile tissue - bulb tas R and L crura
where is the bulb located
midline and attached to undersurface of urogenital diapraghm attached to perineal muscle
what covers bulb of the penis
bulbospongiosus muscle
what covers the crura of penis
ischiocavernosus muscle
the bulb continues into the _____
body and corpus spongiosum
what composes the body of the penis
2 corpus cavernosum and corpus spongiosum enclosed by bucks fascia
what is the distal expanded part of corpus spongiosum
glans penis
what is the prepuce
aka foreskin - hoodlike of skin that covers the glans penis
what is the function of frenulum
connects glands to urethra orifice
what the blood supp of corpus cavernosa
deep arteries of penis
what the blood supp of corpus spongiosum
artery of the bulb and dorsal artery of penis
nerve supp of penis
pudendal nerve and pelvic plexus
what does the scrotum contain
testes, epididymis and spermatic cord
loc of scrotum
outpouching at lower part of anterior abdominal wall
discuss laters of scrotum
skin
superficial fascia
external spermatic fascia
cremasteric fascia
internal spermatic fascia
tunica vaginalis
it covers anterior, medial and lateral surface of testis
tunica vaginalis
comes from external oblique
external spermatic fascia
comes from internal oblique
cremasteric fascia
what comes from fascia transversalis
internal spermatic fascia
blood supp of scrotum
from subcutaneous plexus and arteriovenous anastomoses
- promotes heat loss
nerve supp of anterior scrotum
lioinguinal and genital branch of genitofemoral
nerve supp of posterior scrotum
branches of perineal and posterior cutaneous n. of thigh
what consist the vulva
mons pubis
labia majora
labia minora
clitoris
vestibule
vestibular bulbs
greater vestibular glands
space posterior to clit and labia minora
vestibule
what does the vestibule contain
openings of urethra, vagina, ducts of greater and lesser vestibular glands
blood supp of vulva
from external and internal pudendal
nerve supp of anterior vulva
ilioinguinal n. and genital branch of genitofemoral n.
nerve supp of posterior vulva
branches of perineal nerve and posterior cutaneous n. of thigh
equivalent to male penis
clitoris
parts of the clitoris
root
body
glans
loc of clitoris
at apex and anterior to vestibule
composition of root of clit
bulb of vestibule and R and L of clit
what covers bulb of clit
bulbospongiosus muscle
what covers bulb of clit
bulbospongiosus
what covers crura of clit
ischiocavernous muscle
what composes body of clit
2 corpus cavernosum covered by ischiocavernosus muscle
describe the glans of the clit
erectile tissue w numerous sensory endings; hidden by prepuce
blood supp of clit
internal pudendal artery
nerve of supp clit
pudendal nerve
surrounds orifice of vagina and vestibular bulbs
bulbopsongiosus - also extends to corpus cavernosum of clit
function of bulbopsongiosus
reduces size of vagina orifice and compresses the deep dorsal vein of clitoris to assist erection
found on each side and covers the crus of clit
ischiocavernosus - also assists in erection of clit
muscles of superficial perineal pouch
bulbospongiosum
ischiocavernosus
superficial transverse perineal
describe the perineal body in female
larger kesa s males
function of perineal body
attachment ng levator and assists posterior wall of vagina
parts of deep perineal pouch in female
urethra, vagina, sphincter urethra,
deep transverse perineal
internal pudendal vessels and branches
dorsal nerves of clit
what is the vagina
muscular tube between uterus and vulva
what is the hymen
thin mucosal fold tas perforated sa center
loc of upper vagina
above pelvic floor inside true pelvis
loc of lower vagina
in perineum betw urethra and anal canal
function of vagina
genital canal and excretory duct for mens
what support upper vagina
levator ani
transverse cervical
pubocervical and sacrocervical ligs
what support middle vagina
perineal membrane
what support lower vagina
perineal body
blood supp of vagina
vagina artery from internal iliac
vaginal branch of uterine artey
nerve of vagina
inferior hypogastric plexus
loc of urethra
traverses sphincter urethra until in front of vagina
what are located at sides of urethral meatus
paraurethral glands - skene’s
loc of bartholins glands
under the cover of psoterior parts of vestibule bulb and labia majora
function of bartholins glands
secrete lubricating mucus during sex
where does lesser vestibular glands open to
small ducts on each side of external urethral orifice
desrcibe the path of catheterization in male
external orifice sa glans
spongy urethra
membranous part
prostatic part
preprostatic
urethral floor
bladder