Anatomy and histology of the male pelvis L3 Flashcards
what is the roof of the pelvic cavity made of
the abdominal cavity floor
what is the small pocket of hindgut which goes into the umbilical cord
allantois
what is the allantois
fluid filled bag (embryological equivalent of a bladder)
what 2 structures does the allantois link up with
the precursor of the rectal canal and urogenital ducts
what is it called when the bladder and GI tract meet up
cloaca
2 parts of the cloaca
urogenital and anus
what is the remnant of the allantois bag on the male bladder called
urachus
what are the developmental kidneys attached to the gonads called
mesonephros
what duct drains the mesonephros
mesonephric ducts
what does mesonephric mean
middle kidney
what duct runs along side the mesonephric duct
the paramesonephric duct
what does the paramesonephric duct drain
nothing
what are the paramesonephric ducts also called
mullerian
what are the mesonephric ducts also called
wolffian
where does the gonad begin to form
in the surface of the mesonephros at the back of the abdomen
in males what degenerates
the mullerian duct (paramesonephric duct)
and mesonephros
what causes the duct to degenerate
circulating hormones
what is left behind after the mesonephros degenerates
connecting tubules that connect the gonads to the mesonephric duct
what does the mesonephric duct become
ductus deferens
so overall what has the duct system from the gonads developed from
the duct system for the temporary kidneys
where do the urethers drain into the bladder
high on the posterior surface (loop under ductus deferens)
what path do the ductus deferens follow around the bladder
loop over ureters just as the ureters are entering the bladder and come down the back surface
where do the ductus deferens penetrate into
the prostate gland which sits at the base of the bladder
what are the accessory glands on the back of the male bladder called
seminal vesicle
where do the ducts of the seminal vesicles drain into
the prostate
what 2 structures drain into the prostate
seminal vesicles
ductus deferens
what structure drains into the bladder
ureters
what comes out of the prostate
the urethra (continuation of the bladder)
2 histological zones of the prostate
central zone
peripheral zone
what does the prostate completely encompass
the urethra as it leaves the bladder
where are you most likely to find a carcinoma in the prostate
peripheral zone
where are you most likely to find a benign prostatic hypertrophy in the prostate
the central zone
3 anatomical zones of the urethra
prostatic
membranous
spongy or penile
the longest section of urethra=
spongy/ penile
shortest part of the urethra
membranous (passes through perineal membrane which is very thin)
most proximal part of the urethra
prostatic
spongy part of urethra can be divided into
bulbar region
pendular region
the bulbar region of the spongy urethra=
where penis is still attached to the pelvis and perineal membrane
the pendular region of the spongy urethra
where it is external to the body
do the anatomical sections of the urethra match with the histological
No
3 histological regions
prostatic region
membranous region —>Spongy region
glans penis region
histology of the prostatic epithelium
transitional epithelium (same as bladder)
histology of the membranous region—-> the spongy urethra
pseudostatified columnar epithelium
histology of the glans penis
stratified squamous epithelium
perineum=
area between pubic synthesis and the coccyx
shape of pelvic outlet=
diamond shape
what is the pelvic outlet inferior to
the pelvic diaphragm muscles
what forms the roof of the perineum
pelvic diaphragm (sheet of muscles)
what does the perineum contain (3)
anal canal
distal urethra
external genitalia
what can the pelvic outlet be divided into
anterior and posterior triangle
what is the anterior triangle
urogenital
what is the posterior triangle
anal
four bony landmarks of the pelvic outlet
ischial tuberosity (lateral) x2 pubic synthesis (anterior) coccyx (posterior
hole in the anterior triangle=
urogenital hiatus
hole in the posterior triangle=
anal hiatus
the pelvic diaphragm (floor of pelvis) is the boundary between
the perineal and the pelvis
2 muscle types making up this floor
levator ani
coccygeus
3 levator ani muscles
iliococcygeus
pubococcygeus
puborectalis
iliococcygeus=
from ilium to coccyx
pubococcygeus=
pubic bone to coccyx
puborectalis=
from pubic bone wrapping around the back of the rectum and attaching on the pubis opposite side
muscle of the pelvis not part of the diaphragm but has a tendinous sheet that attaches levator ani muscles =
obturator internus muscle
why do the pelvic muscles need good tone
to keep things in the pelvis
where is the perineal membrane found
only in the urogenital triangle
What are the lateral attachments for the perineal membrane
the ischial tuberosities
anteriorly how is the perineal membrane attached
all the way along the bone with a small gap at the pubic synthesis
what is the 1 hole in the male for in the perineal membrane
the urethra
what is the thin space in the perineal membrane called
the deep perineal pouch
in the male what does the deep perineal pouch contain
bulbourethral glands
what are the spaces between the pelvic diaphragm muscles and the skin called
ischio-anal fossa
what is the space called between the perineal membrane and the skin
the superficial perineal pouch
what is in the superficial perineal pouch
erectile tissue
2 types of erectile tissue in the male
corpus cavernosus
corpus spongiosum
which erectile tissue runs along the shaft and adhered to the bone and perineal membrane
corpus cavernosus
which erectile tissue is singular and stuck onto the surface of the perineal membrane
corpus spongiosum
what is the difference in the urogenital groove in males and female s
zips up in males doesn’t zip up in females
what forms the penis (2)
the genital folds and the genital tubercle
what specifically forms the glans penis
the genital tubercle
what are the labia in the female homologous with in the male
the skin of the scrotum
what 2 openings in the female does the urogenital groove have
one for the urethra
and one to the vagina
what is equivalent to the corpus spongiosum in the female
bulb of the vestibule
whats equivalent to the glans penis in the females
glans clitoris
what muscle covers the corpus caverosum
ischiocavernous muscle
what muscle covers the corpus spongiosum
bulbospongiosus
what does the bulbospongiosus have in the middle
a raphe (bc its been zipped up)
what is the perineal body
a tendon with common attachments to many muscles
what muscles are attached to the perineal body (3)
back end of bulbuspongiosus
two pairs of the superficial transverse perineal muscles
the external anal sphincter
what is the superficial transverse perineal muscle
located on the free margin of the perineal membrane
what nerve roots is the pudendal nerve made from
S2 S3 and S4
where are the parasympathetic fibres coming from
S2 and S3
where are the sympathetic fibres coming from
T10-L2
what does parasympathetic do (3) penile region
vasodilation
stimulate erection
stimulate bladder contraction
what does sympathetic do (4)
cause smooth muscle contraction
internal urethral sphincter constriction
relaxes urinary bladder
ejaculation
perineum artery=
internal pudendal artery
what in the perineum has a separate blood supply
testes
testes blood supply=
abdominal vessels
perineum vein=
veins follow arteries and drain into internal pudendal v
what vein is the exception
deep dorsal vein drains prostate plexus
