2. • First of all we have to discuss about two questions
Question 1-Why we need to pass sometime diluted urine or concentrated urine?
Question 2.How kidney pass concentrated and diluted urine?
Normal osmolarity of blood~300 mosmol/L
Answer1.Blood osmolarity should not be disturbed
3. Asim
• Body fluids tends to hypoosmolar(decrease by
300)
• Kidney should pass out more water to regulate
the osmolarity of blood but waste solute
remains same and urine vol.is more as much as
20L/day
• Asim Drink a lot of water
Let suppose :-
4. • Ahsan lost in desert
• Body fluids getting
concentrated and tends to
be hyperosmolar.
• Kidney should pass
concentrated
urine,solute remain
same but urine vol. is
less.
5.
6. • Whenever body fluids is getting hyperosmolar ,urine should get
hyperosmolar
If blood osmolarity changes less than 1% ,kidney start changing the
osmolarity of urine.
7. Question 2.How kidney pass concentrated and diluted urine?
Requirements:-
1. Hyperosmolar renal medullary
interstitium
• How M.I.H IS produced
• Counter current multiplyer
• Urea recycling in medullary
interstitium
• How M.I.H is maintained
By VASA RECTA
• As counter current exchanger.
• In a normal healthy person ,meduinterstitium must be hyperosmolar which has
capability to concentrate or dilute the urine.
22..Role of ADH
1. Hyperosmolar renal medullary
interstitium
10. How ADH WORKS
• ADH receptors present on THE PRINCIPLE CELLS of late DCT,cortical C.T,medullary C.T
• ADH binds with receptor
• Stimulates G-stimulatory,which activate adenalyl cyclase
• A.C convert AMP into cAMP and phosphorylate special type of vesicle which have
Aquaporin -||
• Aquaporin starts motility toward lumen after phosphorylation and fuse with
lumen
• Lumen is now permeable to water and water reabsorbed ifrom latter part
of nephron
• Urine get concentrated
• If ADH is not present it means there is no water pores in luminal membrane
and water cannot go back so person will pass out diluted urine because lat
part of nephron remain water impermeable
