Lecture 4: Regulation of Kidney Development 1 Flashcards
(44 cards)
What % of CO and volume of blood does the adult kidney filter?
~25% of the CO (1.1L/min)
What do the kidneys regulate?
pH, water and salt balance, BP, renal hormones and waste removal
What is the number of nephrons you are born with and how much does this vary between people?
1,000,000
10 fold variation between people
What are the 3 pairs of excretory organs that form during development and where do they develop from?
Pronephroi, mesonephroi, metanephroi - develop from the intermediate mesoderm
What day does the pronephros form?
21-22 days gestation (human)
In what organism is the pronephros the final kidney?
Primitive organisms
What animals is the pronephros functionally important in?
Amphibians and fish
What is the position of the glomus in the pronephros?
Sits within the ceceum - blood filters and is collected by the pronephric duct
Where does the mesonephros develop?
Beneath degenerating pronephros
What does the pronephic duct give rise to and what does this structure then give rise to?
Wolffian duct
Mesonephros
When does the mesonephros develop?
Day 25
What things are not present in the mesonephros?
Juxtaglomerular apparatus and loop of henle
How many complete nephrons capable of excreting urine are present in the mesonephros?
40
When is the mesonephros at maximal size?
Day 33
What do mesonephric tubules form?
Efferent tubules of the testis in the male
When does the metanephros form?
Day 30
Why does the human kidney finish development just before birth?
Maximise nephron number and renal capacity
What is the final nephron number regulated by?
Ureteric bud branching, MET and apoptosis
What does specification of the metanephric blastema form?
Glomerulus and tubules
What is the functional kidney in mammals?
Metanephros
Where does the UB outgrowth begin?
Caudal end of Wolffian duct
What are the steps of ureteric branching and morphogenesis?
- The UB invades the metanephric mesochyme (MM)
- Metanephric mesochyme and UB produce messages to communicate and cause induction of UB to branch
What does the ureteric tree form?
Collecting ducts, calyces and renal pelvis
What does the part of the UB that does not enter the MM form?
Ureter