Renal Regulation of Acid/Base Balance Flashcards Preview

Physiology Renal ABS 2018 > Renal Regulation of Acid/Base Balance > Flashcards

Flashcards in Renal Regulation of Acid/Base Balance Deck (39)
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1
Q

What is the principle of acid-base balance?

A

input=output

whatever you put in must go out

2
Q

What are the 5 points of entry for acids and bases?

A
  1. De novo from metabolism
  2. Processing of digested foods
  3. GI tract from digestion
  4. Metabolism of stored fat and glycogen
  5. Kidneys
3
Q

What is a buffer?

A

a buffer is solution that prevents large changes in pH after the addition or loss of protons from external sources

4
Q

What is the dominant buffer int the ECF?

A

Bicarbonate-HCO3-

5
Q

What is the dominant buffer int the ECF?

A

Bicarbonate-HCO3-

Co2 + H20—H2Co3

6
Q

What is the dominant buffer of the ICF?

A

Phosphates
Protein
more fluid in ICF then ECF

7
Q

What is acidosis? When a patient has what are the 2 possible causes to choose betwen? and how do you know which it is?

A

decrease in pH; Increase [H+]
caused by:
-increase in proton conc.-change in ion gap
-loss in base–no change in ion gap

8
Q

What is alkalosis?

A

increase in PH; decrease [H+]
Caused by:
-Base gain
-decrease proton concentration

9
Q

What 2 structures within what structure in the kidney handle acids and bases?

A
  1. Proximal Tubule
    -reabsorb an enormous amount of bicarb
  2. Distal Tubule
    -secrete H+ or bicarb(always reabsorbed first) to balance net output
    Both are structure throughout/within the nephron
10
Q

How do we move/buffer fluid between ECF and ICF?

A

K/H exchanger
Acidosis: H+ into cell/K+out of cell
Alkolosis: H+ out cell/K+ in cell

11
Q

What happens when we keep CO2 in the body? (i.e holding breath, low ventilation)

A

Increase Co2
Increases [H+]
decrease PH

12
Q

What is the mechanism of Na/H+ exchanger bicarb reabsorption in the distal tubule?

A

Use an Na/H+ anti-porter-apical membrane that pumps H+ out into lumen– H+ combines with HCO3 to form H2CO3—broken down to water and CO2—Bicarbonate is gone

Na/HCO3 symporter on basolateral membrane
Pumps HCO3 and pumps it back out into the blood—New Bicarb

13
Q

What happens when increase ventilation?

A

Decrease Co2
Decrease [H+]
Increase PH

14
Q

What hormone increases sodium reabsorption through the Na/H exchanger?

A

Angiotensin II

15
Q

What are the two cells are found in the distal tubule?

A
  1. Principle

2. Intercalated Cells

16
Q

What are two types of intercalated cells?

A
  1. Type 1 -alpha

2. Type 2- active in alkaosis

17
Q

What is the mechanism of Cl-/HCO3- ?

A

same mechanism except for Cl being symported together with

18
Q

What are the two types of reabsorption transports in the proximal tubule?

A
  1. Na/H exchanger

2. Cl- Transporter

19
Q

What are 2 types transport mechanism for bicarbonate reabsorption in the in the distal tubule?

A
  1. K/ ATPase

2.

20
Q

What is the mechanism of bicarbonate reabsorption of Type A of distal tubule?

A

H/K ATPase

—-H2CO3 —breaks down into—HCO3 + H=

21
Q

What are the two responses to excess acid in the blood?

A
  1. HPO4—

2. Amonium

22
Q

What is base load?

A

excrete base,

excrete bicarb intercalated cells

23
Q

What happens in an acid load ?

A

excess acid

  1. get rid of acid
  2. replace lost bicarb with new bicarb
24
Q

What is the mechanism of bicarb formation via titratable acids?

A

K/H+ exchanger

pumps out H+ combine w/HPO4 and excreted in lumen and HCO3 is resborbed back into interstium

25
Q

Where does the generation of titratable acids occur?

A

Proximal tubule

26
Q

What is the process of ammonium formation?

A

catabolism of protein—creation of glutamine— glutamine taken up in the distal tubule–glutamine is converted NH4+ +HCO3—NH4+ secreted into lumen; bicarb exits into interstium

27
Q

How do we quantify how much new bicarb has been made by the kidneys?

A

NAE =TA+NH4-HCO3

28
Q

Where do we secrete bicarb?

A

distal tubule

29
Q

What are 4 factors that can cause acidosis?

A
  1. Acid gain
  2. Decreased respiration
  3. keto-acids
  4. base loss diarrhea
30
Q

What are 4 factors that can cause acidosis?

A
  1. decreased respiration
  2. keto-acids
  3. renal failure
  4. base loss diarrhea
31
Q

What causes the formation of keto-acids?

A

alternate fuel soource

Ketone bodies, seen in diabetes

32
Q

What are 4 factors that can cause acidosis?

A
  1. decreased respiration/ventilation
  2. keto-acids
  3. renal failure
  4. base loss diarrhea
33
Q

What is the anion gap equation?

A

AG=Na-HCO3

Normal between 8-12

34
Q

What is the point of testing the anion gap?

A

it allows you to determine acid again or base loss in the body.
if you have acid gain A-, it will increase the u

35
Q

What is the point of testing the anion gap?

A

it allows you to determine acid again or base loss in the body.
if you have acid gain A-, it will increase the unknown anions in the plasma, therby increasing the gap
if it is a base loss anion gap will stay the same

36
Q

Why will anion gap stay the same when there is a base loss?

A

chloride will replace the lost bicarbonate

37
Q

What causes alkalosis?

A
  1. Lose acid

2. Gain base

38
Q

What are the 4 ways a patient can develop alkalosis?

A
  1. hyperventilation
  2. vomitting
  3. bicarb overdose
    4.
39
Q

What are the 4 ways a patient can develop alkalosis?

A
  1. hyperventilation
  2. vomitting
  3. bicarb overdose
  4. chronic dieuretic usage