Renal Physl 16

Question 1

What can cause blood volume and osmolarity to both increase?

Answer 1

Salty food being consumed more than liquid

Question 2

What is comparable to intake of a hypertonic solution?

Answer 2

Eating salty foods more than water intake

Question 3

How does a hypertonic solution affect ECF and osmolarity?

Answer 3

ECF volume and osmolarity increase

Question 4

How is the urine affected by increased ECF and osmolarity?

Answer 4

A hypertonic urine is produced where sodium and water are excreted

Question 5

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

Answer 5

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

Question 6

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

Answer 6

Isotonic urine is produced

Question 7

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

Answer 7

Ingesting pure water

Question 8

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

Answer 8

ECF is diluted

Question 9

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

Answer 9

A large volume of dilute hypotonic urine

Question 10

What may be stimulated if plasma osmolarity dips to low?

Answer 10

Salt apatite

Question 11

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

Answer 11

Consuming solutes in the absence of fluid intake

Question 12

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

Answer 12

Small volume of concentrated urine

Question 13

What triggers the thirst mechanism?

Answer 13

When blood volume is unchanged but plasma osmolarity increases

Question 14

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

Answer 14

A dehydrated person who only ingests pure water

Question 15

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

Answer 15

It causes ECF to be diluted

Question 16

What was the idea behind gatorade?

Answer 16

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

Question 17

What can cause a reduced blood volume and increased osmolarity?

Answer 17

Diarrhea or excessive sweating where more water is lost than solute

Question 18

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

Answer 18

Elderly people and babies

Question 19

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

Answer 19

A hemorrhage

Question 20

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

Answer 20

Blood transfusion or isotonic saline infusion

Question 21

What is the goal in response to dehydration?

Answer 21

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

Question 22

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

Answer 22

Conserving fluid and prevent loss by rapid cardiovascular reflexes and thirst

Question 23

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

Answer 23

Blood volume and blood pressure decrease and plasma osmolarity increases

Question 24

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

Answer 24

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

Question 25

What is the result of the increased cardiovascular input in dehydration?

Answer 25

It increases sympathetic outflow with a decrease in parasympathetic

Question 26

What does the increased sympathetic activity in dehydration do?

Answer 26

It causes peripheral vasoconstriction increasing resistance which raises BP. It also increases HR and contractility which increases cardiac output

Question 27

What happens as a result of reduced renal perfusion seen in dehydration?

Answer 27

Increased renal sympathetic activity causes juxtaglomerular cells to release renin which initiates the RAAS system

Question 28

What are the multiple effects of angiotensin II in dehydration?

Answer 28

• It acts at the cardiovascular system to increase cardiac output
• Powerful vasoconstrictor
• Stimulates the release of vasopressin
• Boosts water intake through thirst

Question 29

How does low blood volume and pressure due to dehydration affect glomerular capillary hydrostatic pressure and GFR?

Answer 29

It decreases glomerular capillary hydrostatic pressure and GFR

Question 30

Why is low GFR a good thing in dehydration?

Answer 30

The less fluid filtered, the less that is lost in the urine. This also stimulates juxtaglomerular cells to produce renin

Question 31

How does sympathetically mediated constriction of the afferent arteriole affect GFR?

Answer 31

It contributes to the volume conservation and RAAS activation by decreasing GFR

Question 32

Where is information from atrial volume receptors and carotid and aortic baroreceptors integrated?

Answer 32

At the hypothalamus

Question 33

What does information integrated at the hypothalamus during dehydration stimulate?

Answer 33

The release of vasopressin and thirst

Question 34

How does dehydration affect hypothalamic osmo receptors?

Answer 34

Because dehydration increases osmolarity, it causes osmoreceptors to shrink triggering vasopressin release

Question 35

When is Aldosterone released?

Answer 35

• In response to low pressure and volume

* In response to decreased plasma osmolarity (low solutes)

Question 36

What two signals are found in dehydration?

Answer 36

• Low pressure and volume

* Increased plasma osmolarity

Question 37

How does the low BP and increased plasma osmolarity affect aldosterone release?

Answer 37

Because low BP stimulates aldosterone and increased plasma osmolarity inhibits aldosterone they cancel each other out and the net effect is suppression of aldosterone