4.4_2 Renal II Part II Flashcards Preview

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Flashcards in 4.4_2 Renal II Part II Deck (40):
1

ECF Volume regulation is also known as...

Long term regulation of blood-pressure

2

Distribution of body water is between what three compartments?

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

3

Distribution of body water is determined by what?

Number of osmotically active particles in each

4

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

Na+
Cl-

5

If Na+ is retained...

So is water

6

Changes to plasma volume drive changes to...

Interstitial fluid volume (since they are in equilibrium)

7

What changes the plasma volume?

Na+ content

8

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

1)Atrial natriuretic peptide
2) Renin Angiotensin Aldosterone System

9

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

Na+ reabsorption in distal convoluted tubule and collecting duct

10

Atrial Natriuretic Peptide responds to...

High blood pressure
High blood volume

11

Atrial Natriuretic Peptide leads to..

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

12

Stimulus of ANP

Increased stretch of baroreceptors in atria

13

Control center of ANP

Atria release ANP into the blood

14

Net effect of ANP

Peripheral resistance decreases, blood volume decreases, decreasing blood pressure

15

RAAS

Renin-Angiotensin-Aldosterone-System

16

RAAS = Salt _____ = _____ plasma volume

Retention
Increased

17

What does RAAS begin with?

Renin

18

What is renin?

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

19

Why would renin be released from the juxtaglomerular apparatus?

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

20

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

Baroreceptors of the afferent arteriole

21

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

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

22

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

Increased sympathetic stimulation of the arterioles in the juxtaglomerular apparatus

23

Cells of the JGA

Granular cells
Macula densa

24

Granular cells

Specialized smooth muscle cells that produce renin in response to stimuli

25

Macula densa

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

26

What does renin do? (cascade)

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

27

Is angiotensin I active?

No, it is inactive

28

What is ACE and what does it do?

Angiotensin converting enzyme
Converts Angiotensin I to Angiotensin II

29

Where is ACE located?

In the lungs

30

What are ACE inhibitors?

Very common medication for hypertension

31

Angiotensin II causes..

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

32

What does aldosterone do?

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

33

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

Via increased expression of transport proteins

34

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

K+ secretion

35

Receptor and control center for aldosterone secretion

Adrenal cortex

36

Kidneys regulate blood pH by altering plasma ____

HCO3-
(Bicarbonate)

37

Normally, is all HCO3- reabsorbed from the filtrate?

Yes

38

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

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

39

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

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

40

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

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