Kidneys deel 2 Flashcards
What can be regulated by hormones?
Concentration of urine is adjusted according to the water and salt balance in the body and the rate at which urea is made
What is ADH and what does it do (3)?
Anti-Diuretic Hormone
-Binds to receptors on the collecting duct
-Aquaporins are incorporated in the collecting duct – >
-The more aquaporis ,the more uptake of water, the smaller urine volume
What happens when you have Diabetes insipidus? (3)
Mutations in ADH receptor or disturbed ADH production:
- High urine production
- High water intake (5-15l per day)
What is the effect of alcohol on ADH? (2)
- Decreases ADH production
- More water leaving via urine (less aquaporins = less absorption of water)
What does RAAS do? (Renin Angiotensin Aldosterone System)
Responds to a drop in blood volume/pressure by increasing water and Na intake in the distal tubal
(RAAS vervolg) What happens when drop in blood volume/pressure is registered by JGA?
Renin is released
What does Renin do? (4 steps)
- Converts angiotensinogen into angiotensin II.
- Angiotensin II causes vasoconstriction and stimulates aldosterone release
- Aldosterone increases Na and water reabsorption in distal tubes.
- Blood pressure increases again
What is GFR?
Glomerular Filtration Rate
-All extracellular fluid is filtered every hour
What does disease of kidney impact? (3)
1 The water and salt balance
2 PH of blood
3 Removal of waste
Up to what % of Nephron loss are there no symptoms?
80-90%
What are ways to measure renal function? (3)
Clearance
Plasma creatinine / eGFR
Glomerular Integrity
What is measured with Clearance?
Measure how well a substance is excreted in the urine
What does clearance mean?
Volume of blood from which substance is removed in 1 minute
Where do clearance measurements take place?
Urine and plasma
Why is Plasma creatinine/GFR measured?
There is a relationship between GFR and plasma creatinine production
= Decreasing GFR by 50% increases creatinine twice if creatinine production is normal
