renal 3 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

what determines the final urine concentration and volume (3)

A
  • ultrafiltration at glomerulus
  • selective reabsorption in tubules (water and solutes)
  • tubular secretion of solutes
  • *simultaneously determine ECF concentration and composition as well**
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

define glomerular filtration (ultrafiltration)

A
  • bulk flow of fluid from glomerular caps to bowman’s
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are freely filtered in glomerular filtration

A
  • low molecular weight substances such as:

- ions, Na, K, Cl, HCO3, glucose, urea etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does filtration depend on in glomerular caps

A

starling forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is different about the glomerular cap than the other caps

A
  • Hydrostatic pressure is higher at the glomerular cap
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the ONLY job of the glomerulus

A

FILTRATE (no reabsorption)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the layers that a filtrate passes

A
  • overall filtration passes from capillary lumen –> bowman’s capsule
  • needs to pass through endothelial layer, basement membrane, podocytes and epithelial layer of bowmans.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the only barrier to RBC

A
  • highly spaced epithelial cells of the cap (not big enough for RBC)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define Congenital nephrotic syndrome

A
  • mutation in podocin gene –> lose protein/edema
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What effect does charge have to do with glomerular filtration

A
  • part of a barrier
  • endothelial layer is lined with NEGATIVE charged mucopolysaccharides to prevent filtering proteins (everything else is fair game)
  • this is why proteins are much LESS PERMEABLE
  • also filtration slits in podocytes are negatively charged
  • -> results in repeling large neg. charged proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What forces favor filtration

A
  • capillary hydrostatic pressure (cap. BP) because glomerulus is between 2 high pressure circuits
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What force opposes glomerular filtration

A
  • capillary oncotic pressure because it pushes filtrate out on afferent side and into glomerulus so there is more protein on the efferent side, so more oncotic pressure
  • Hydrostatic Pressure in Bowman’s (important if there is renal obstruction-stones)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where are the forces favoring net filtration biggest?

A

Forces favoring filtration biggest on AFFERENT END

–> decrease to near 0 at end of efferent end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the effects of filtration if polyanionic substance lose a charge?

A
  • lots of (-) charge so no filtration (like protein)
  • start filtering the proteins causing edema
  • proteinuria and albuminuria occurs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe colloid osmotic pressure

A
  • normally it is always increasing because it only filters

- only goes down if starting to reabsorb water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the substances that constrict both afferent and efferent arterioles

A
  • NE and Epi

- decrease GFR and RBF (only occurs in extreme conditions like hemorrhage)

17
Q

describe angiotensin II

A
  • consticts Afferent arterioles
  • maintains GFR and decrease RBF by constricting afferents
  • effect is on efferent despite constriction of the afferent
18
Q

What happens if you raise hydrostatic pressure

A

The GFR increaes

19
Q

What occurs if the plasma oncotic pressure increases

A

Increase in plasma oncotic pressure –> GFR will decrease (bolus or protein) –> GFR decrease

20
Q

what occurs if you start sweating alot

A

sweat a lot, lose all but proteins so oncotic pressure increases –> GFR DECREASE

21
Q

what is the result on filtration of a Person with GI illness with vomit/diarrhea

A

vomitting/diarrhea cause the loss of protein-free fluid so get SAME

22
Q

What occurs in the case of kidney stone obstruction

A

kidney stones obstruct ureter so hydrostatic in bowman’s rise –> causing a DECREASE in GFR

23
Q

define filtration fraction

A
  • FF=GFR/RPF
  • percent of renal plasma flow (RPF) filtered at glomerulus
  • if FF increased, oncotic pressure at efferent end increases above normal
24
Q

define transport maximum

A
  • max rate at which glucose can be reabsorbed in the lumen
  • a person with very high blood glucose levels will also have high urine volume due to transport max being reached and glucose spills into urine
  • -> since glucose is osmotically active and keeps Na and thus water in the urine (resulting in high levels of urine)