development of the GU system Flashcards
when does gastrulation happen
week 3
when does cephalo-caudal and lateral folding happen
18 days
what does folding create
tube of pharynx and oesophagus, stomach, GI tract, glands
what is the allantois
a sac that is part of the conceptus that helps the embryo handle waste
later becomes a canal that drains the urinary bladder of the fetus that joins the umbilical cord
what does the urogenital sinus form
urethra and bladder
what separates the cloaca into the urogenital sinus and rectum
urorectal septum
what tissue makes up the posterior abdominal wall
the mesoderm
what do the lateral folds do
close the body wall and enclose the intraembryonic coelom
what tissue makes up the somites adjacent to the notochord and neural tub
mesoderm
what does the lateral plate mesoderm form
the coelom
what does the coelom become
the peritoneal cavity
what are the 3 stages of the renal primordia
pronephros
mesonephros
metanephros
where do the renal primordia form
in the mesoderm of the posterior abdominal walls
where do the mesonephric ducts open in to
the cloaca
what two structures make up the kidney
ureteric bud and the metanephric blastema
what does the ureteric bud form
the ureter and collecting ducts
what does the metanephros form
the renal tissue (glomeruli and loops of Henle)
when is the kidney functional
10 weeks
what happens if the collecting ducts do not meet the nephric vesicles
cysts form within the kidney
what congenital kidney defects may arise
pelvic kidney and horseshoe kidney
what abnormalities may arise in the ureter
bifid ureter
failure to branch leading to renal agenesis
what is the urachus
a fibrous remnant of the allantois which is a canal that drains the urinary bladder of the fetus that joins and runs within the umbilical cord.
what does the urorectal septum become
the perineal body
how does the anal canal form
cloacal membrane ruptures
what forms the phallus
the genital tubercle
what does the proximal part of the UG sinus form
the bladder
what does the pelvic part of the UG sinus form
the prostatic and membranous urethrae
what four structures contribute to the urinary system
the metanephros, uteric bud, urogenital sinus and the allantois
what do mesonephric and paramesonephric ducts form
the reproductive ducts and structures
what forms the gonad
mesoderm of the genital ridge which is developed from the overlying coelomic epithelium; and germ cells that have migrated from the yolk sac
what cells go on to produce ova and sperm
germ cells
what forms the female genitalia
the paramesonephric duct
the mesonephric duct degenerates due to lack of testosterone
what is a Gartner’s cyst
a remnant of the mesonephric ducts which form cysts near the vagina, epoophoron and paraoophoron
at what week does sexual differentation occur
week 8 to week 12
what is the appendix epididymis
remnant of the proximal end of the mesonephric ducts
what is the appendix testis and prostatic utricle
remnants of the paramesonephric ducts
what does the mesonephric duct form when it moves caudally
the epididymis, vas and seminal vesicle
what is the sino vaginal bulb derived from
the posterior aspect of the urogenital sinus
what do the two paramesonephric ducts fuse with
the sino vaginal bulb
how does proximal vagina and uterus form
the ducts zip together in a cranial direction
how do the uterine tubes form
the Mullerian ducts stay seperate as the left and right uterine tubes with fimbriated ends that open into the peritoneal cavity
how does the broad ligament form
As the ducts lift off the posterior
abdominal wall they lift peritoneum as
the broad ligament
describe some uterine abnormalities
double uterus and double vagina double uterus bicornate uterus separated uterus unicornate uterus cervical atresia
what is the gubernaculum
a cord that connects the testes with the bottom of the labioscrotal folds and causes descent of the testes in the fetus
what two ligaments tether the gonads
the suspensory ligament and gubernaculum
what does the gabernaculum do in the male
shrinks to draw the testes down the posterior abdominal wall to the inguinal canal then through the canal at 8 months so the testes should be in the scrotum by birth
what does cryptorchidism mean
failure of the testes to descent
what does the gubernaculum form in the female
round ligament
what is the processus vaginalis
the testes take a loop of peritoneum with them which remains as the tunica vaginalis
what is the tunica vaginalis
the serous covering of the testis
what happens if the processus vaginalis stays open
indirect inguinal hernia and hydrocele
what is hydrocele
the accumulation of serous fluid in a body sac
what forms the endodermal urethral plate
the UG sinus
what structures are formed by the urethral plate
the genital tubercle, the UG folds and the labioscrotal folds to form the external genitalia
what forms the scrotum
genital swellings on either side of the urethral fold
how does the penile urethra form
As the penis elongates, the edges of the urethral folds move
towards each other and fuse in the midline. the urethra ‘zips up’ from proximal to distal
what is hypospadias
failure of the urethral folds to form or to extend along the penis and fuse
the urethra opens onto the ventral surface of the penis
why are connections and fistulae of the UG tract and the rectum/ anal canal common
common origin and proximity
What is the cloaca
the distal hindgut which will go on to form the rectum, anal canal, urogenital system
what structures make up the renal primordia
pronephros
mesonephros
metanephros
where do the kidneys form
pelvis and then travel upwards
if the uteric bud fails to reach the metanephros why wont the kidney form
the uteric bud induces development
what are somites formed from
mesoderm
what is the coelom formed from
mesoderm
what is the urinary and reproductive system formed from
mesoderm and coelomic epithelium
what is the vas formed from
mesonephric duct
what forms the prostate and membranous urethrae
the pelvic part of the UG sinus
what does the prostate form from
the urethra
what is the genetic basis for female sex
absence of the Y chromosome and the SRY gene
what is the SRY gene
sex determining region Y
found on the Y chromosome and involved in male sex determination
what duct forms the fallopian tube, uterus and upper part of the vagina
Mullerian duct
what duct forms the epidymis and vas
Wolffian duct
what forms the lower third of the vagina
sinovaginal bulb which is an endodermal bud of the UG sinus
what does the UG sinus form in males
upper -urinary bladder
pelvic - prostatic and membranous urethra
phallic - urethra
what does the UG sinus form in females
pelvic- sinovaginal bulb - lower vagina
upper- bladder
