Embryology of the Renal System Flashcards
What are the 3 germ layers of the embryo?
Ectoderm
Mesoderm
Endoderm
What of the 3 germ layers does the kidneys form from?
Mesoderm
What are the 3 parts of the mesoderm?
Paraxial
Intermediate
Lateral
What part of the mesoderm does the kidneys form from?
Intermediate mesoderm
What does the dorsal aorta form?
Descending aorta
What are the 3 stages of kidney development in the embryo?
Pronephros
Mesonephros
Metanephros
At what end of the embryo does the intermediate mesoderm begin to segment?
What does this form?
When about does this occur?
Cranial end
Pronephri
Day 22
Are pronephri functional?
No
What do the pronephri become?
Mesonephros
Where does the filtrate from mesonephros drain to?
Mesonephric duct which is forming alongside the mesonephri
Are mesonephri functional?
Yes
How many mesoneprhic tubules are originally formed?
How many are left once these have regressed?
What happens to the remaining mesonephric tubules?
40
20
Function as excretory units between weeks 6-10 and then regress
When do the mesonephric tubules begin to regress?
End of week 5
What vertebral levels are the remaining mesonephric tubules left at?
L1-L3
What develops at approximately week 5?
Metanephros
When does the metanephros begin to function?
Weeks 9-11 (mesonephros stops functioning at about week 10)
What does the metanephros develop into?
The permanent kidney
What does the metanephros develop from?
Ureteric bud (collecting system) Metanephric blastema (filtering system)