renal 2

Question 1

what is filtration?

Answer 1

filters the plasma from glomerular capillaries into the kidney tubules

BUTT! only 20% is actually filtered
the othe 80% continues to the peritubular capillaries

Question 2

what does the renal corpuscle do in the filtration process?

Answer 2

it is a triple threat barrier

1. capillary endothelial cells (fenestrated)
2. basal lmina (exttracellular matrix)
3. podocyte endfeet

Question 3

what makes filtration harder? (2)

Answer 3

1. colloid osmotic pressure
   -opposes filtration cuz of plasma protiens
2. bowman’s capsul hydrostatic pressure
   -(fluid pressure) opposes filtration

Question 4

What are the 2 functions of the Glomulus Filt4ration Rate (GFR)

Answer 4

• help protect filtration barriers from high blood pressure

1. Myogenic respose of the afferent arterioles (stretch smoothmuscle to bring GFR down)
2. Tubuloglomerular Feedback.
   *macula densa cells: have cilia that sense distal tubule flow and release paracrine signals that affect afferent/efferent diameter

Question 5

how do sympathetic neurons have an infulence on GFR?

Answer 5

-intergrating centers outside of kidneys can override local mechanisms

-they alter resistance or filtration coefficent through sympathetic neurons by releasing NE on A1 adrenergic receptors on either AA or AE arterioles (only when sharp drpo in blood pressure due to hemorrage or deyhdration)

Question 6

How do hormones influence GFR?

Answer 6

-Angiotensin II is a potent vasoconstrictor

-prostoglandins, vasodialators