Renal 2 Flashcards Preview

PHSI 208 > Renal 2 > Flashcards

Flashcards in Renal 2 Deck (26)
Loading flashcards...
1
Q

The epithelium around glomerular capillaries is modified into…

A

podocytes (leaving slits through which filtration takes place)

2
Q

mesangial cells

A

located between the capillaries that contract to alter blood flow (filtration)

3
Q

the renal corpuscle

A

a triple filtration barrier

4
Q

triple filtration barrier

A

-capillary endothelial cells
-basal lamina
podocyte endfeet

5
Q

capillary endothelial cells are ________________ so things can pass through.

A

fenestrated

6
Q

Which 3 pressures govern filtration from glomerular capillaries into the renal tubules?

A
  • hydrostatic pressure
  • colloid osmotic (oncotic) pressure
  • Bowman’s capsule hydrostatic pressure
7
Q

hydrostatic pressure

A

of blood in the glomerular capillaries favours filtration; ~55mmHg

8
Q

colloid osmotic (oncotic) pressure

A

the pressure gradient due to the presence of plasma proteins and opposes filtration; ~30mmHg

9
Q

Bowman’s capsule hydrostatic pressure

A

fluid pressure that opposes filtration; ~15mmHg

10
Q

net filtration pressure is…

A

10mmHg (55-30-15)

11
Q

The volume of fluid that filters from the glomerular capillaries into the Bowman’s capsules per day?

A

180L/day

12
Q

The kidneys filter our entire plasma volume approximately…

A

60x/day

13
Q

What 2 factors influence glomerular filtration rate (GFR)?

A

net filtration pressure and filtration coefficient

14
Q

net filtration pressure

A

renal blood flow and blood pressure

15
Q

filtration coefficient

A

the surface area of the glomerular capillaries available for filtration and permeability of interface between capillaries and Bowman’s capsule

16
Q

GFR is primarily regulated by..

A

renal arterioles (afferent and efferent)

17
Q

Autoregulation maintains a constant GFR when mean arterial blood pressure is…

A

between 80 and 180 mmHg

18
Q

Renal blood flow’s resistance is determined by…

A

both the afferent and efferent arterioles (overall resistance)

19
Q

What two auto-regulatory mechanism maintain a relatively stable GFR in the face of normal blood pressure fluctuations

A
  • myogenic response of the afferent arterioles

- tubuloglomerular feedback

20
Q

tubuloglomerular feedback

A

local control pathway in which fluid flow through the tubule portion of the nephron

21
Q

macula densa cells

A

sense distal tubule flow and release paracrine that affect afferent arteriole diameter

22
Q

granular cells

A

secrete renin, an enzyme involved in salt and water balance

23
Q

Flow __________ passed macula dense cells

A

increases

24
Q

Increased _____ has been shown to activate macula densa cells.

A

NaCl

25
Q

Sympathetic activation only really alters GFR under conditions of…

A

hemorrhage or severe dehydration

26
Q

What two hormones modulate arteriole resistance and filtration coefficient by acting on podocytes and/or mesangial cells?

A

angiotensin II (vasoconstrictor) and prostaglandins (vasodilator)