pelvis Flashcards
describe the anatomical and surface borders of the perineum
what divides the anorectal and urogenital triangle ?
line between ischial tuberosities
what are the contents of the anorectal triangle
anal apeture
external anal sphincter
ischioanal fossae
pudendal nerve
where is the perineal membrane?
attaches to inferior pubic rami inferior to levator ani but superior to perineal muscles
what is the function of the perineal membrane?
cover urogenital hiatus
where is the deep perineal pouch?
between deep pelvic fascia overlying levator ani and perineal membrane
(superior to the perineal membrane)
where is the superficial perineal pouch?
between perineal membrane and superficial perineal fascia
inferior to the perineal membrane
describe the layers of the superficial perineal fascia
deep fascia - overlies superficial perineal muscles and covers protruding structures such as the penis and clitoris
superficial fascia
- made up of two layers: continuation of scarpers (aka colles fascia here) and campers
(membranous and fatty layer)
what is within/passes through the deep perineal pouch in men/women?
both:
- urethra
- EUS
Females:
- vagina
males:
- deep transverse perineal muscles
- bulbourethral glands (within EUS)
what passes through/is in the superficial perineal pouch in men/women?
superficial perineal muscles
erectile tissue of penis/clitoris
females only: bartholian glands (aka greater vestibular glands)
what is the perineal body and where is it?
fibromuscular mass - marks the boundary between the anorectal and urogenital triangle in both men and women
centre for attachment of pelvic floor muscles (levator ani and superficial perineal muscles)
where does the pudendal nerve run?
from sacral plexus
out greater scaitic foramen
back in through lesser sciatic foramen
along the inner surface of the ischial tuberosity - Alcocks canal (with pudendal artery and vein) - pudendal nerve block
what are the 3 superficial perineal muscles?
bulbospongiosus
ischiocavernosis
superficial transverse perineal
what nerve innervates the levetor ani and superficial perineal muscles?
pudendal nerve
what muscles make up the levator ani?
puborectalis
pubococcygeus
iliococcygeus
what is the scrotal ligament a remnant of?
gubernaculum
where is the dartos muscle?
superficial muscle of the scrotum just deep to the skin
function is to wrinkle the skin of the scrotum to regulate temperature
where do the lymphatics of the teste drain to?
para-aortic and lumbar (due to testicular descent)
what abdominal muscle does not form part of the spermatic cord?
transversus abdominis
label the following
what muscles overly the proximal parts of these structures?
bulbospongiosus
ischiocavernosus
what is bucks fascia?
continuation of the deep layer of superficial perineal fascia which surrounds the penis holding the erectile tissue together and anchors it
draw out the spermatic cord and its contents
describe the pathway of sperm
made in the seminiferous tubules
drain into the rete testis then into the epididymis (head)
pass through the body then tail of epididymis into the vas deferens
travel through the vas to the prostatic urethra where the vas joins the urethra
pass out through the urethra
label the hemisected pelvis
where is the frenulum of the penis?
ventral surface - connect the prepuce to the glans
what does the penile suspensoy ligament attach to?
bucks fascia and pubic symphysis
label this crossection
where does the superficial dorsal vein of the penis drain into?
superficial external pudendal vein -> great saphenous
where does the deep dorsal vein of penis drain into?
prostatic plexus -> internal iliac
where do the arteries of the penis arise from?
internal pudendal artery
describe the difference in bloody supply of the penis and teste
penis and scrotum - internal pudendal artery, drain into internal pudendal vein mainly
teste - artery arises directly from aorta, venous drainage into left renal vein and IVC
what key structures does the vas pass over?
internal iliac artery and vein
ureter
what are bulbourethral glands also known as?
cowpers
where are the seminal vesicles in relation to the ampulla of the vas
inferio-lateral
where is the ejaculatory duct?
in prostate at the junction of the seminal vesicles with the vas deferens
the ejaculatory duct then joins with the urethra
(remember IUS prevents retrograde ejaculation back un into bladder here
name the parts of the male urethra
pre-prostatic - IUS
describe the areas of the prostate
transitional - surrounds proximal urethra
peripheral - surrounds distal urethra
central - surrounds the ejaculatory duct
what are the 3 branches of the pudendal nerve?
Inferior rectal nerve – innervates the perianal skin and lower third of the anal canal.
Perineal nerve – innervates the skin of the perineum, labia minora and majora or posterior scrotum.
Dorsal nerve of the penis or clitoris – innervates the skin of the penis or clitoris. Thus, responsible for the afferent component of penile and clitoral erection.
fill in the missing labels
what female structures are analogous to the male bulb of the penis, corpus spongiosum and the glans?
bulb of vestibule and glans of clitoris
what is the difference in the structure of the bulb of the vestibule in females and the bulb of the penis in males?
males - joined in the midline
females - divides into 2 around the vestibule
fill in the missing labels
where do the cardinal ligaments attach?
cervix to lateral walls of pelvis
where does the ovarian ligament attach?
ovary to uterus
where is the ovarian fossa?
between external and internal iliac vessels on lateral pelvic wall
where do the gonadal veins drain?
right - IVC around level of renal vein
left - left renal vein
where do the gonadal arteries branch from and travel?
aorta just below left renal vein (which passes over aorta)
travel over the ureters and external iliac vessels
where does the uterine artery branch from?
internal iliac (anterior division)
what arteries anastamose on the uterus?
uterine and ovarian
what is th difference between anteverted and anteflexed?
anteverted - means the cervix is rotated anteriorly relative to the vagina
anteflexed means the uterus is rotated anteriorly relative to the cervix
what are the male analogous structures of the following?
- labia majora
- labia minora
- glans clitoris and bulb of vestibule
- skenes glands
- round ligament and ovarian ligament
- labia majora - scrotum
- labia minora - penile urethra
- glans clitoris and bulb of vestibule - bulb of penis and corpus spongiosum
- skenes glands - prostate
- round ligament and ovarian ligament - scrotal ligament
what is the abdominal ostia in relation to the uterine tubes?
where the infundibulum opens into the peritoneal cavity
what are the branches of the posterior division of the internal iliac artery
iliolumbar
lateral sacral
superior gluteal
where does the internal iliac divide into anterior and posterior division?
just above greater sciatic foramen
what are the branches of the anterior division of the internal iliac artery
inferior gluteal
internal pudendal (out greater sciatic foramen and back in lesser then through adcocks canal)
middle rectal
vaginal arteries + uterine arteries (inferior vesicle artery in males supplying prostate)
obturator artery
superior vesicle arteries
umbillical artery (medial umbilical ligaments left )
describe the location of the urinary bladder
sits directly posteriorly to the pubic symphysis
superior to the pelvic diaphragm in the lesser pelvis
when full extends into greater pelvis
describe the areas of the bladder
fundus = trigone
what nerve innervates the EUS in both sexes?
pudendal nerve - voluntary control
what nerve causes relaxation of the bladder allowing storage reflex?
hypogastric nerve - sympathetics
what nerves cause contraction of the detrusor allowing the micturition reflex?
pelvic nerves - parasympathetics
where is the superior boundary of the rectum?
S3 - within the true pelvis
where there is no longer a sigmoid mesentery - this is rectum
note here how the rectum curves to the right, then left then back to the right due to the transverse flexures
what forms the border between the rectum and anal canal?
pectinate (dentate) line
what is the significance of the pectinate line?
different embryological origins
above - hindgut
below - ectoderm
