Renal Physl 16 Flashcards

1
Q

What can cause blood volume and osmolarity to both increase?

A

Salty food being consumed more than liquid

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2
Q

What is comparable to intake of a hypertonic solution?

A

Eating salty foods more than water intake

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3
Q

How does a hypertonic solution affect ECF and osmolarity?

A

ECF volume and osmolarity increase

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4
Q

How is the urine affected by increased ECF and osmolarity?

A

A hypertonic urine is produced where sodium and water are excreted

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5
Q

What will cause blood volume to increase but plasma osmolarity to remain normal?

A

The salt and water ingested is the same osmolarity of the plasma so only volume is expanded

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6
Q

What kind of urine is produced if blood volume is increased and plasma osmolarity is normal?

A

Isotonic urine is produced

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7
Q

What would cause blood volume to increase and osmolarity to decrease?

A

Ingesting pure water

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8
Q

What would happen to the ECF if blood volume is increased and osmolarity is decreased by ingesting pure water?

A

ECF is diluted

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9
Q

What kind of urine would be produced if Blood volume is increased and osmolarity decreases?

A

A large volume of dilute hypotonic urine

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10
Q

What may be stimulated if plasma osmolarity dips to low?

A

Salt apatite

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11
Q

What may cause blood volume to remain unchanged but plasma osmolarity to increase?

A

Consuming solutes in the absence of fluid intake

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12
Q

What kind of urine is produced if blood volume is unchanged but plasma osmolarity is increased?

A

Small volume of concentrated urine

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13
Q

What triggers the thirst mechanism?

A

When blood volume is unchanged but plasma osmolarity increases

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14
Q

What may cause blood volume to be unchanged but plasma osmolarity to be decreased?

A

A dehydrated person who only ingests pure water

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15
Q

How do unchanged blood volume and decreased plasma osmolarity affect the ECF?

A

It causes ECF to be diluted

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16
Q

What was the idea behind gatorade?

A

When exercising people lose water and salt so gatorade contains fluid and electrolytes to replenish that without diluting ECF

17
Q

What can cause a reduced blood volume and increased osmolarity?

A

Diarrhea or excessive sweating where more water is lost than solute

18
Q

Whos is most susceptible to reduced blood volume and increased osmolarity?

A

Elderly people and babies

19
Q

What may cause a reduced blood volume but an unchanged osmolarity?

A

A hemorrhage

20
Q

What is the treatment for reduced blood volume and unchanged osmolarity?

A

Blood transfusion or isotonic saline infusion

21
Q

What is the goal in response to dehydration?

A

To restore blood pressure, extracellular fluid volume and plasma osmolarity by conserving fluid and preventing losses

22
Q

What is the main way to restore BP, ECF volume and plasma osmolarity in dehydration?

A

Conserving fluid and prevent loss by rapid cardiovascular reflexes and thirst

23
Q

How are blood volume, pressure and osmolarity affected by dehydration?

A

Blood volume and blood pressure decrease and plasma osmolarity increases

24
Q

How does the reduced BP and blood volume seen in dehydration affect carotid and aortic baroreceptors?

A

Reduced stretch of baroreceptors causes them to relay information to the cardiovascular control centers in the brain

25
What is the result of the increased cardiovascular input in dehydration?
It increases sympathetic outflow with a decrease in parasympathetic
26
What does the increased sympathetic activity in dehydration do?
It causes peripheral vasoconstriction increasing resistance which raises BP. It also increases HR and contractility which increases cardiac output
27
What happens as a result of reduced renal perfusion seen in dehydration?
Increased renal sympathetic activity causes juxtaglomerular cells to release renin which initiates the RAAS system
28
What are the multiple effects of angiotensin II in dehydration?
* It acts at the cardiovascular system to increase cardiac output * Powerful vasoconstrictor * Stimulates the release of vasopressin * Boosts water intake through thirst
29
How does low blood volume and pressure due to dehydration affect glomerular capillary hydrostatic pressure and GFR?
It decreases glomerular capillary hydrostatic pressure and GFR
30
Why is low GFR a good thing in dehydration?
The less fluid filtered, the less that is lost in the urine. This also stimulates juxtaglomerular cells to produce renin
31
How does sympathetically mediated constriction of the afferent arteriole affect GFR?
It contributes to the volume conservation and RAAS activation by decreasing GFR
32
Where is information from atrial volume receptors and carotid and aortic baroreceptors integrated?
At the hypothalamus
33
What does information integrated at the hypothalamus during dehydration stimulate?
The release of vasopressin and thirst
34
How does dehydration affect hypothalamic osmo receptors?
Because dehydration increases osmolarity, it causes osmoreceptors to shrink triggering vasopressin release
35
When is Aldosterone released?
* In response to low pressure and volume | * In response to decreased plasma osmolarity (low solutes)
36
What two signals are found in dehydration?
* Low pressure and volume | * Increased plasma osmolarity
37
How does the low BP and increased plasma osmolarity affect aldosterone release?
Because low BP stimulates aldosterone and increased plasma osmolarity inhibits aldosterone they cancel each other out and the net effect is suppression of aldosterone