Renal Function 2 Flashcards
(35 cards)
If the Kidney filters so much and secretes so little then where is all this filtrate going?
Most of the filtrate is returned back to the blood via the proximal tubule
What % of filtrate is returned to the plasma via the proximal convoluted tubule?
65-70% and is relatively non-selective in its absorption
- mostly based on Na co-transport
Na co-transport occurs linked to: (6)
- Glucose
- Amino acids
- Hydrogen ions being secreted
- Phosphate
- Chloride flux
- Water follows passively / osmosis
Histology of proximal tubular cells:
Brush border: had microvilli (increasing surface area)
Basement membrane: packed full of mitochondria (need energy for transporting)
Where does the energy for these co-transport processes come from?
mitochondria from ATPase pump on basolateral surface
excretion of glucose is dependent on?
GFR: It increases with concentration
Peri- tubular capillaries have High___ and Low ___
High: colloid osmotic pressure
Low: hydrostatic pressure
*Favors resorption of water into capillaries
During Proximal tubule function what is absorbed?
glucose, amino acids, and bicarbonate
during proximal tubule function, what remains at the same concentration?
Na and Cl
During proximal tubule functiion what is reabsorbed ?
peptides and small proteins
proximal tubular cells make?
calcitriol
What is the loop of Henle involved in?
the counter-current mechanism to generate a concentrated renal medulla
Animals with long loops of Henle:
are best adapted to concentrate urine
Why does the medulla defrost faster than the cortex?
because it has a higher salt content thsn cortex
What part of the loop of Henle is highly permeable to water?
descending loop of Henle beause concentartion of Na is higher and draws that water out
What about the ascending loop?
impermeable to water
Where is Na, K, and Cl transported out of the tubule (water does not follow)
thick ascending loop
Fluid leaving the tubule is
hypotonic (dilute)
What direction is the flow of blood via hairpin capillaries (Vasa recta)
Opposite direction and flow is slow
*If fast would take away watwr to quickly
Transport process in the thick acending loop of loop is a
NA/K/Cl co-tramsporter
- energy is provided via Na/K ATPase on basolateral surface
What happens to K+
most is recycled back to lumen
The loop of Henle removes more ___ than ___
Na than water therefore fluid that leaves the loop is dilute
another name for late distal tubele?
connecting tubule
What part of the nephron is sensitive to anti-diuretics (ADH)
collecting tubule and collecting duct
- increases water and urea permeability
