Embryo- urinary system Flashcards
what embryonic layer gives rise to the urinary system?
Intermediate mesoderm
what forms the bilateral urogenital ridges?
intermediate mesoderm
name the 3 stages of kidney development
1) Pronephros
2) mesonephros
3) metanephros
Pronephros:
Early in week 4
Develops bilaterally in cervical region
Mesonephros:
weeks 4-10
Develops bilaterally in thoracolumbar region
functions as primitive kidney
metanephros
starts week 5, functional at week 9/10
Develops bilaterally in the pelvic region at the level of the cloaca
Mesonephric vesicle
-functions as Bowman’s capsule; contains glomerulus
-10-15 glomeruli per mesonephric kidney
(degenerates)
Mesonephric tubule
-elongates; acts as tubular part of nephron
Females: degenerates
Males: persists as efferent ductules of testes
Mesonephric duct: what does it become in males? in females?
Females: degenerates
Males: persists as ductus deferens, epididymis, seminal vesicle, ejaculatory duct, trigone
what are the 2 components of the metanephros
- ) Ureteric bud (metanephric diverticulum)
2. ) Metanephrogenic blastema
A small outgrowth develops from the mesonephric duct: the ________
ureteric bud
the Ureteric Bud Gives Rise to what?
Collecting Portion of Kidney
name the mature derivatives of the ureteric bud
Ureter
Renal pelvis
Major & minor calyces
Collecting tubules
The Metanephrogenic Blastema Gives Rise to what portion of the kidney?
Excretory Portion of Kidney
derivatives of the Metanephrogenic blastema:
Distal convoluted tubule
Loop of Henle
Proximal convoluted tubule
Bowman’s capsule
Kidneys “ascend” from the _____ to the _____
when do they assume their final position?
Kidneys “ascend” from pelvis to abdomen
assume final position by week 9
Clinical Correlation: Accessory Renal Arteries
Failure of temporary blood supply to regress leads to accessory renal aa
Horseshoe Kidney
Poles of kidneys fuse together
usually inferior poles
The ___________ divides the cloaca into the urogenital sinus (ventrally) & the anorectal canal (dorsally).
urorectal septum
Urogenital Sinus Derivatives:
- Urinary bladder
- Urethra
- in males: prostate, bulbourethral glands
- females: Vestibule of vagina, vestibular glands
the allantois will eventual close off, forming the ______. this is covered by the ______ in adults
- urachus
- covered by median umbilical fold
what does The trigone develop from?
from the distal portions of the mesonephric ducts
Renal Agenesis:
Failure of one or both kidneys to form
Oligohydramnios is a lack of what?
possible result of renal agenisis
lack of amniotic fluid