Loop of Henle Flashcards
What is the maximum concentration of urine which can be produced by human kidneys?
1200-1400 osmoles/L
What is the minimum daily obligatory water loss?
500mls
What happens with the presence of frusemide?
Only isotonic urine can be produced. NaCl and H2O normally reabsorbed rom loop of Henle are lost so large volume of isotonic urine
What does the concurrent multiplier achieve?
Concentrates fluid on the way down and promptly re-dilutes it on the way back up, by removing NaCl
Creates an increasingly concentrated gradient in the interstitium
Delivers hypotonic fluid to the distal tubule
What is the vasa recta?
The specialised arrangement of the peritubular capillaries of the juxtamedullary nephrons
What are the functions of the vasa recta?
Provide oxygen for medulla
Removes volume from the interstitium
How is the medullary gradient not disturbed by the vasa recta?
Flow rate through vasa recta is very low, plenty of time for equilibrium to occur with the interstitium
What is the main site for water regulation?
Collecting duct
What controls the permeability of the collecting duct?
ADH anti diuretic hormone/ vasopressin
