4.4_2 Renal II Part II

Question 1

ECF Volume regulation is also known as…

Answer 1

Long term regulation of blood-pressure

Question 2

Distribution of body water is between what three compartments?

Answer 2

1) Blood
2) Interstitial Fluid (IF)
3) Intracellular fluid or cytoplasm

Question 3

Distribution of body water is determined by what?

Answer 3

Number of osmotically active particles in each

Question 4

___ and ___ are the major “osmolyte” salts that draw water into compartments

Answer 4

Na+

Cl-

Question 5

If Na+ is retained…

Answer 5

So is water

Question 6

Changes to plasma volume drive changes to…

Answer 6

Interstitial fluid volume (since they are in equilibrium)

Question 7

What changes the plasma volume?

Answer 7

Na+ content

Question 8

Regulation of Na+ content is achieved through what two ways?

Answer 8

1) Atrial natriuretic peptide

2) Renin Angiotensin Aldosterone System

Question 9

Each method of regulating Na+ content is ultimately influencing what?

Answer 9

Na+ reabsorption in distal convoluted tubule and collecting duct

Question 10

Atrial Natriuretic Peptide responds to…

Answer 10

High blood pressure

High blood volume

Question 11

Atrial Natriuretic Peptide leads to..

Answer 11

Increased salt emanation and hence increases water elimination (shuts down the recapturing of sodium)

Question 12

Stimulus of ANP

Answer 12

Increased stretch of baroreceptors in atria

Question 13

Control center of ANP

Answer 13

Atria release ANP into the blood

Question 14

Net effect of ANP

Answer 14

Peripheral resistance decreases, blood volume decreases, decreasing blood pressure

Question 15

RAAS

Answer 15

Renin-Angiotensin-Aldosterone-System

Question 16

RAAS = Salt _____ = _____ plasma volume

Answer 16

Retention

Increased

Question 17

What does RAAS begin with?

Answer 17

Renin

Question 18

What is renin?

Answer 18

An enzyme produced by specialized smooth muscle cells within juxtaglomerular apparatus surrounding the afferent arterioles of the kidney

Question 19

Why would renin be released from the juxtaglomerular apparatus?

Answer 19

Severe blood loss
Low Blood pressure
Low salt intake
Low plasma & Filtrate sodium
Stress, trauma, exercise

Question 20

What is severe blood loss and low blood pressure sensed by in RAAS system?

Answer 20

Baroreceptors of the afferent arteriole

Question 21

What is low salt intake and low plasma &filtrate sodium sensed by in the RAAS system?

Answer 21

Reduced delivery of Na+ to the macula densa cells (DCT)

Question 22

What is increased stress, trauma and exercised sensed by i the RAAS system?

Answer 22

Increased sympathetic stimulation of the arterioles in the juxtaglomerular apparatus

Question 23

Cells of the JGA

Answer 23

Granular cells

Macula densa

Question 24

Granular cells

Answer 24

Specialized smooth muscle cells that produce renin in response to stimuli

Question 25

Macula densa

Answer 25

Cells assess NaCl in DCT filtrate (If Na+ is low, it promotes renin secretion from the granular cells)

Question 26

What does renin do? (cascade)

Answer 26

Activates Angiotensin (from liver) to Angiotensin I by taking off some amino acids

Question 27

Is angiotensin I active?

Answer 27

No, it is inactive

Question 28

What is ACE and what does it do?

Answer 28

Angiotensin converting enzyme | Converts Angiotensin I to Angiotensin II

Question 29

Where is ACE located?

Answer 29

In the lungs

Question 30

What are ACE inhibitors?

Answer 30

Very common medication for hypertension

Question 31

Angiotensin II causes..

Answer 31

(a) A global vasoconstriction of arterioles | (b) Increases secretion of the adrenal cortical steroid hormone ALDOSTERONE

Question 32

What does aldosterone do?

Answer 32

Increases the capacity of the distal tubule and collecting duct to reabsorb Na+

Question 33

How does the distal tubule and collecting duct reabsorb Na+?

Answer 33

Via increased expression of transport proteins

Question 34

Aldosterone: Na+ and H2O reabsorbed at the expense of....

Answer 34

K+ secretion

Question 35

Receptor and control center for aldosterone secretion

Answer 35

Adrenal cortex

Question 36

Kidneys regulate blood pH by altering plasma ____

Answer 36

HCO3- | Bicarbonate

Question 37

Normally, is all HCO3- reabsorbed from the filtrate?

Answer 37

Yes

Question 38

What cells express carbonic anhydrase to drive the CO2 + H2O to Bicarbonate reaction?

Answer 38

Type A and Type B Intercalated cells of the nephron PCT and collecting duct

Question 39

Increase in [H+] in plasma (acidosis0 would lead to..

Answer 39

Type A cells move more H+ into filtrate in tubule lumen, increase HCO3- in the blood

Question 40

Decrease in [H+] in plasma (alkalosis) would lead to...

Answer 40

Type B cells secrete less H+, excrete excess plasma HCO3- (into filtrate)