Kidney Development Flashcards
In what direction do the kidney systems develop?
Three overlapping kidney systems form form the intermediate mesoderm in a cranial to caudal direction.
Where is the urogenital system derived from?
The urogenital system is derived from the common mesodermal ridge along the posterior wall.
Initially, excretory ducts of both systems enter into a common cavity known a the cloaca.
What are the 3 embryological kidney systems?
Pronephros (rudimentary and non-functional)
Mesonephros (transient)
Metanephros (forms the permanent kidney
When does the pronephros system form?
The pronephros forms at the beginning of week 4 and disappears by the end of week 4.
What do the 7-10 cell groups of the pronephros form?
The 7-10 solid cell groups form nephrotomes.
When does the mesonephros begin to develop?
At the end of week 4/start of week 5, the first excretory tubules appear from original block of unsegmented mesoderm.
What forms the Bowman’s capsules?
The excretory tubules from the mesonephros form the Bowman’s capsules.
A tuft of capillaries around the medial end of tubules yield glomeruli.
During which week are the cranial tubules and glomeruli degenerating with the caudal still differentiating
Week 6.
During week 6, what is happening to the caudal tubules in males and females?
During week 6, in the male some caudal tubules still persist in formation of genital system.
In the female, the caudal tubules regress.
When does the metanephros begin to function?
The metanephros begins to function by Week 9.
What does the metanephros arise from?
The metanephros arises from 2 structures.
1. Metanephric blastema.
2 Ureteric bud. (Outgrowth of mesonephric duct.)
From what origin does the excretory system of the kidney arise from?
The excretory system of the kidney develops from metanephric blastema.
From what origin does the collecting system of the permanent kidney arise from?
The collecting system of the kidney develops from Ureteric bud.
What structures of the collecting system does the ureteric bud eventually form?
The Ureteric bud eventually forms:
Ureter, renal pelvis, major calyces, minor calyces, collecting ducts and tubules (which form the pyramids.)
If the Ureteric bud splits too early, what can happen?
If the Ureteric bud splits too early in development, bifid ureter can arise.
