B5-040 Renal Physiology III Flashcards
(64 cards)
1
Q
plasma minus protein
A
ultrafiltrate
2
Q
functional unit of kidney
A
nephron
3
Q
triple layer of glomerulus
A
- endothelial cell
- basement membrane
- podocytes
4
Q
factors involved in filtration
3
A
- size/charge of molecules
- properties of membrane (surface area, permeability)
- forces (GHP, COP, CHP)
5
Q
how is GFR regulated?
2 mechanisms
A
- autoregulation
- extrinsic
6
Q
main function is reabsorption
all is Na+ dependent
A
proximal tubule
7
Q
2nd reabsorptive phase
works to concentrate or dilute urine
A
loop of Henle
8
Q
which part of the tubule is aldosterone regulated?
A
distal tubule
9
Q
which part of the tubule is ADH regulated?
A
collecting tubule
10
Q
product of protein metabolism in liver
A
urea
11
Q
why is BUN more a marker of tubule function?
A
depends on urea transporters
12
Q
regulation of urea is closely linked with
A
ADH
13
Q
where can uric acid accumulate?
A
joints –> gout
heart valves –> valve disease
kidneys –> kidney stone
14
Q
urine output < 50 ml
A
anuria
15
Q
urine output of 300-500 ml/day
A
oligouria
16
Q
urine output > 3L/day
A
polyuria
17
Q
ECF osmolarity depends on
A
Na+ concentration
18
Q
main regulator of water reabsorption/secretion
hormone
A
ADH
19
Q
ECF volume depends on
A
total body Na+ content
20
Q
what part of the pituitary secretes ADH
A
posterior
21
Q
ADH targets the
A
collecting duct
water reabsorption
22
Q
ADH effect on urine
A
increased osmolarity
decreased volume
23
Q
describe the regulation of ECF osmolarity through the hypothalmus
high ECF osmolarity
A
- ECF osmolarity increases
- triggers osmoreceptors in thirst center of hypothalmus
- triggers ADH release from posterior pituitary
- ADH acts on collecting tubule to increase water reabsorption
- more water enters plasma, decreases osmolarity
24
Q
- promotes water reabsorption
- causes vasoconstriction
A
ADH
25
the circulating concentration of ADH is directly linked to
serum osmolality
| slight changes in osmolality effect ADH concentration
26
[...] changes in pressure are needed to ellicit change in ADH
| small or big
big
| 10%
27
ADH binds to [...] receptors in the kidney
V2
| V2 --> cAMP --> PKA --> AQ2
28
ADH stimulates phosphorylation of [...] to apical membrane
AQ2
| water enters cell --> more water in **plasma**
29
AQ2 allows water into the cells, increasing the concentration of water in the
| serum or urine
serum
30
Anti-diuresis requires what two factors?
* ADH to increase renal tubular permeability
* a gradient that will favor water reabsorption
31
creates the gradient needed for ADH action later
loop of Henle
32
transporter that is always basolateral
NaKATPase
33
transporters in ascending loop of Henle
basolateral: NaKATPase
apical: NKCC
| bring salt from tubule into interstitium
34
salt from the ascending loop of Henle will accumulate in the interstitium and then move into
descending loop of Henle
| salt is slowly added to fluid as it moves through descending loop, water
## Footnote
water out
35
salt is slowly added to fluid as it moves through the [...] loop of Henle
descending
| salt in, water out
36
what part of the loop of Henle is impermeable to water?
ascending
37
osmolarity [...] in the descending loop of Henle
increases
| salt coming in, water going out
38
osmolarity [...] in the ascending loop of Henle
decreases
| salt out, water stays same
39
reduces the osmolarity of fluid in the tubule
| what part of tubule
loop of Henle
| creates gradient for reabsorption in collecting duct
40
unless ADH is present, the walls of the collecting duct are [...] to water
impermeable
41
diluting segment of the loop of Henle
ascending
42
ADH [...] the osmolarity of fluid in the collecting tubule
increases
| water reabsorbed
43
how would the absence of ADH affect urine concentration?
low osmolarity
high volume
44
what part of the kidney has the highest salt concentration?
medulla
45
what structure protects the countercurrent mechansim and supplies nutrients to the cell?
vasa recta
46
the juxtaglomerular nephrons have longer loops of Henle and participate in
concentrating the urine
47
the nephrons in the cortex with very short loop of Henles are mainly for
filtration
48
why does blood flow through the vasa recta have to be slow?
when increased, more salt is reabsorbed from the interstitium which **decreases the countercurrent effects**
49
low protein diets decrease urea. How would that effect the countercurrent mechanism?
decreases countercurrent mechanism
| high urea concentrations favor the countercurrent mech.
50
furosemide inhibits
NKCC
| inhibit Na+ reabsorption, more urine production
51
acute ECF volume expansion trigger the release of
atrial natriuretic peptide
52
decreases renal tubular sodium and fluid reabsorption
atrial natriuretic peptide
53
released due to distension of the atria
atrial natriuretic peptide
54
after a prolonged period without water intake, ECF decreases and the [...] is activated
sympathetic nervous system
| alpha-1-adrenoreceptors
55
causes systemic vasoconstriction, including the glomerular afferent arteriole
alpha 1 adrenoreceptors
56
increases the permeability of distal and collecting tubules causing water to be reabsorbed
ADH
57
effectiveness of the countercurrent mechanism requires:
| 3
1. ADH
2. urea in the kidney medulla
3. salt reabsorption in the loop of Henle
58
an increase in blood flow through the vasa recta will cause
salt in the renal medulla to be washed away
| decrease effectiveness of countercurrent mech.
59
a decrease in salt delivery to the macula densa will trigger the release of
renin
60
aldosterone activates
| 2
NaKATPase
ENaC
61
activates NaKATPase at the basolateral membrane of the principal cells of the collecting tubules
aldosterone
62
a negative value for the UAG indicates
kidneys are producing and excreting NH4+
63
what conditions cause hyperkalemia?
| shifting K out of cell
**D**igoxin
hyper**O**smolarity
**L**ysis of cells
**A**cidosis
**B**-blockers
high blood **S**ugar (insulin deficiency)
**S**uccinylcholine
| DO LABSS
64
what conditions cause hypokalemia?
| shifting K+ into cell
hypo osmolarity
alkalosis
B agonist
insulin
| insulin shifts K+ INto cells
