Development of the Urinary system Flashcards
the urogenital system develops from what type of the mesoderm
intermediate mesoderm
the intermediate mesoderm forms a longitudinal ridge that is called ?
urogenital ridge
the kidneys develop in what type of sequence somatotopically
cranial to caudal
what are the 3 developing kidney systems in chronological order
- pronephros
- mesonephros
- metanephros
when and where does the pronephros develop ?
day 21-24
-cranially in the cervical segments of the intermediate cords
which kidney system is rudimentery and which becomes the adult kidney
pronephros - rudimentery/nonfunctional
metanephros - becomes functional kidney
when and where does the mesonephros develop
weeks 5-10
-thoracic and lumbar segments of the intermediate mesoderm
is the mesonephros functional ?
Yes, produces and drains urine during weeks 5-10
in the mesonephros what is the structure that drains the urine produced leading to the bladder
mesonephric duct (Wolfian duct) - or nephrogenic duct
what develops into the primordial nephron ?
consolidation of about 40 mesonephric tubule
the mesonephric duct extends caudally untill it fuses with ____, making up the ____ portion of the bladder
cloaca, posterior portion
what initiate the formation of the uteric bud ?
canalization of the mesonephric cord
what is the adult derivative of the uteric bud
metanephric diverticulum
canalization of the mesonephric duct occurs in what direction somatotopically
caudal to cranial
what are the 2 componets of the metanephros
- Collection portion
- excretory portion
when and where does the uteric bud develop
week 5 in the distal portion of the mesonephric duct
the formation of the uteric bud induces the sacral region of the intermediate mesoderm to form what ?
metanephric blastema
the collecting portion of the metanephros develops from what ?
uteric bud
the excretory portion of the metanephros develops from what ?
metanephric blastma
what does reciprocal induction mean with reference to the metanephros
it means that the uteric bud is needed to “induce” nephron differentiation
- aka to induce the metanephric blastema
- if the uteric bud doesnt develop, then rest of kidney doesnt develop
what parts of the adult kidney arise from the collecting portion of the metanephros
- ureter
- renal pelvis
- major/minor calyces
what parts of the adult kidney arise from the excretory portion of the metanephros
- bowmans capsule
- PCT
- loop of henle
- DCT
when do the kidneys start to ascend and what causes them to ascend
around week 6-9
-growth in length of the embryo forces them cranially
As the kidney ascends does it drag its original vasculature with it, or develop new blood supply strategies
Does NOT drag
-develops new renal a..
What are the 3 potential clinical malformations if the kidneys do not ascend correctly
1 - pelvic kidney -ectopic/out of place
2 - horeshoe kidney
3 - supernumery arteries - >1 renal aa. entering hilum
**2 and 3 not cause long term effects***
what is the cloacal membrane divided by what ?
urorectal septum
the urorectal septum divides the cloacal membrane into ?
- ventral urogenital sinus
- dorsal anorectal canal
what are the 3 parts of the ventral urogenital sinus and what do they become
- vesicle part - anterior portion of bladder
- pelvic part - urethra
- phallic part - spongy urethra (men)
what is the posterior aspect of the bladder made up of ?
-distal portions of the mesonephric duct
what is the trigone and where can it be found
a triangular region of pulled down mesonephric ducts forming the posterior aspect of the bladder
what makes up the posterior vs. anterior aspects of the bladder
posterior - trigone of mesonephric ducts
anterior - vesicle part of ventral urogenital sinus
what develops from the pelvic part of the urogenital sinus in women
entire urethra and vagina
what develops from the pelvic part of the urogenital sinus in men
prostatic and membranous urethra
what develops from the phallic part of the urogenital sinus in men
spongy urethra
what are the 3 possible types of clinical malformations when the intraembryonic allantois does close off properly from the cloacal membrane
1 - urachal cyst - pocket of swelling when both ends are pinched off
2 - urachal sinus - closure at 1 end and open on the other
3 - urachal fistula - allantois not closed at either end resulting in dripping urine from umbilicus
what is exstrophy of the bladder and how does it occur
where the mucosal lining of the bladder is outside the body wall b/c the closing off of the external oblique did not occur on the anterior abdominal wall
