Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Renal > 05.08 - Reg of Body Fluid Osmolarity (Rao) - PP + Handout, No reading > Flashcards

05.08 - Reg of Body Fluid Osmolarity (Rao) - PP + Handout, No reading Flashcards

(64 cards)

Start Studying
1
Q

4 Causes of Loss of Medullary Hyperosmolarity

A

(1) Diuretics; (2) Excessive delivery of fluid into LOH; (3) Decreased urea production; (4) Age, renal failure

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

Ability of kidneys to dilute or concentrate urine depends on

A

Difference between osmolar clearance and clearance of water

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

Activation of V2 in CD results in

A

insertion of Aquaporins into luminal membrane

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

Actual fluid flow - Cosm =

A

Free water clearance

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

ADH receptor in Epithelial cells of CD

A

V2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

ADH responds to both

A

Posm, ECFV

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

At what plasma osmolarity does AVP reach max

A

295 mOsm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

At what plasma osmolarity is AVP detectable

A

270-285 mOsm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

AVP increase requires what threshold of ECFV loss

A

10-15% decrease in ECFV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Cause of Osmotic Diuresis

A

Hyperosmotic Plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Central Diabetes Insipidus results from

A

Pituitary gland doesn’t release AVP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Common symptom of decreased ability to concentrate urine

A

Nocturia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Complications of Polydipsia

A

Hyponatremia, Coma, Death

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

Cwater =

A

UF x (1 - Uosm/Posm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Dec PV after GI loss causes ___, but decreased plasma osmolarity causes ____

A

Inc AVP, Dec AVP

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

Difference between osmolar clearance and water clearance is

A

Free Water Clearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does ADH affect Posm, Uosm in Osmotic Diuresis

A

Remains: High, High

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does ADH affect Posm, Uosm in Primary Polydipsia

A

Low to Normal, Low to High

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does CD help with Medullary Hyperosmolarity

A

Active transport of Na into ISF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does GI fluid loss lead to hyponatremia

A

(1) AVP release in response to volume; (2) Dilution of plasma; (3) Inc ECF volume; (4) Reduced osmolarity, Hyponatremia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does heart failure cause hyponatremia

A

Loss of pressure stimulates hypovolemic hormone release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How does IMCD help with Medullary Hyperosmolarity

A

Passive diffusion of urea into ISF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How does liver failure cause hyponatremia

A

Loss of PV stimulates hypovolemic hormone release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How does Thick AL help with Medullary Hyperosmolarity

A

Active NaCl transport, Co-transport of K and Cl into ISF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How does Water Deprivation affect Posm, Uosm, and ADH in Nephrogenic DI
Increase, No change, Increase
26
How does WD affect Posm, Uosm, and ADH in Osmotic Diuresis
Inc, Inc, Inc
27
How does WD affect Posm, Uosm, and ADH in Primary DI
Increase, Remain low, No change
28
How does WD affect Posm, Uosm, and ADH in Primary Polydipsia
Normalize, Normalize, Increase
29
If free water clearance is negative, it means
Urine is being concentrated and BW is retained
30
If Uosm is greater than Posm
Negative Cwater -\> Concetrated Urine -\> Dec Posm
31
If Uosm is less than Posm
Positive Cwater -\> Dilute urine -\> Inc Posm
32
In condition of sever ECFV loss, it doesn’t matter what \_\_\_, ___ will rise
Doesn’t matter what serum osmolarity is, AVP levels will rise
33
Manifestations of Hyponatremia
Lethargy, Hyporeflexia, Mental confusion
34
Mutations that can cause Nephrogenic Diabetes Insipidus
V2 receptor, Aquaporin-2 --\> CD doesn't respond to AVP
35
Na imbalance with GI fluid loss
Hyponatremia
36
Normal Cosm
2 +- 0.5 mL/min
37
Obligatory Urine volume
.5 L / day
38
Osmolar Clearance =
(UF x Uosm) / Posm
39
Osmolar clearance is elevated under condition of
Plasma Hyperosmolarity
40
Osmolar clearance measures
kidney's ability to concentration urine
41
Calculated Plasma Osmolarity =
2 x Na + (glu/18) + (bun/2.8)
42
Positive free water clearance indicates
Dilution of urine and concentration of plasma
43
Resting Posm, Uosm, and ADH in Osmotic Diuresis
High, High, Normal
44
Substantial dec in ECFV stimulates ADH release even
under condition of hypo-osmolar plasma
45
T/F: ADH increases linearly with decreased ECFV
False, logarithmic - Very slow increase at first until threshold met
46
Thick Ascending Limb is permeable to
Active NaCl transport, (K, Cl)
47
Thin Ascending Limb is permeable to
Passive NaCl, some urea
48
Thin Descending Limb is permeable to
H20, some urea
49
To assess efficacy of kidney to concentrate or dilute urine, must first
quantitate the rate of excretion of solute (using Osmolar Clearance)
50
Two other conditions besides GI Fluid Loss that lead to Hyponatremia with no change in ECFV
(1) Heart Failure - Loss of pressure stimulates hypovolemic hormones; (2) Liver failure - Reduce PV stimulates hypovolemic hormones
51
Two special features that contribute to preservation of medullary interstitial hyperosmolarity
(1) Meduallry BF is low; (2) Vasa recta serves as countercurrent exchanges
52
Tx of Hyponatremia due to GI Fluid Loss
Infusion of Isotonic Saline, avoid quick change
53
Under condition of severe volume loss, effect of ___ on ___ overides \_\_\_
Effect of ECFV loss on AVP overrides osmolarity effect
54
Urea contributes what % of osmolarity in Medullary ISF
40%
55
Water clearance is how much
water without any solute is cleared in urine
56
Water deprivation in DI must be stopped if
BW falls \>5%, Posm \> 300 mOsml/kg
57
What can override normal response to plasma osmolarity
Severe decrease in ECFV
58
What is dilemma with severe volume loss and low serum osmolarity
Low osmolarity inhibits ADH so as to correct; But severe volume loss overrides in order to maintain volume
59
What signals mediate V2 activity
AC -\> cAMP -\> PKA
60
Where are osmoreceptors in the brain that stimulate ADH release in response to increase osmolarity
Supraoptic and Paraventricular Nuclei of Hypothalamus
61
Where is AVP degraded
PT and Liver
62
Where is the thirst center in the brain?
Lateral Preoptic Nucleus of the Hypothalamus
63
Which is more efficient: Clearing water or conserving
Clearing fo sho
64
Which part of CD is permeable to Urea
Inner Medullary

Renal (31 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions