Urinary development Flashcards
What embryonic layer is responsible for a majority of the urinary structures?
The intermediate mesoderm
List the three urinary systems at 4.5 weeks:
Pronephric system
Mesonephric system
Metanephric system
Where does the kidney arise?
The metanephric system, from unsegmented mesoderm.
What embryonic tissue is the gonad derived from?
The intermediate mesoderm
What channels are part of the metanephric system?
The mesonephric (Wolffian) and paramesonephric (Mullerian) ducts
The excretory tubules acts as glomerulus - these dissapear in female, but conduct sperm in males
What forms the primitive kidney?
The metanephric blastema
The ureteric bud develops into the collecting ducts of the kidney and causes the metanephric balstema to differentiate into the nephrons
What are the parts of a nephron?
The glomerulus, the Bowman’s capsule, and excretory tubules.
What are the regulatory molecules of kidney development?
WT1: Master gene for kidney development
Mutations in WT1 result in Wilms tumor
What regulatory molecules does the ureteric bud produce?
Bone morphogenetic protein 7 (BMP 7) and Fibroblast growth factor 4 (FGF4)
What are mutations in genes that interact with Glial cell line-derived neurotrophic factor (GDNF)?
SALL1 Townes Brocks syndrome
Pax2 Renal coloboma syndrome
EYA1 Branchio-oto-renal syndrome
cause renal dysplasia/ agenesis
What is lack of excretion of amniotic fluid called?
Oligohydramnios results from lack of excretion of amniotic fluid
Renal agenesis = Primary defect
1:4000-8000 births (probably more common)
2:1 males vs females (Y chromosome genes)
Defects secondary to oligohydramnios*
Facial compression
Lower limb defects (clubfeet)
Lung hypoplasia
Collectively referred to as Potter syndrome
Polycystic disease
Recessive form: 1:5000; cysts from collecting tubules; renal failure in infancy
Dominant form: 1: 500-1000: cysts from anywhere; renal failure in adulthood
How does the primitive urogenital sinus connect to outside of the embryo?
The allantois connects to the umbilical cord
Where does the mesonephric duct terminate at the caudal end of the embryo?
The urogenital sinus
What embryonic tissue is the trigon derived from?
Mesodermx
What is an ectopic ureter?
When the ureter terminates in the urethra or vagina
What is a urachal fistula?
When the allantois fails to “close down”
Epiblasts - migrate from primitive streak to the posterior wall of the yolk sac during gastrulation, then migrate to develop the kindeys
This is caused by lack of fusion between urethral folds
The metanephric blastema forms all of the following besides?
The efferent tubules
