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Flashcards in Acid Base Deck (55):
1

Below what pH are we in acidosis?

7.35

2

Above what pH are we in alkalosis?

7.45

3

What is the normal range for pH?

7.35 - 7.45 (ECF fluid pH)

4

How do acids enter our body?

Ingestion (we eat a LOT more ACIDS than bases), normal cellular metabolism

5

What's the pathway of excess acids when they get into our body?

H+ first buffered by Bicarb & protein in ECF then H+ moves into ICF via H+/K+ exchanger where its buffered by phosphates (H2PO4) and protein, kidney secretes H+ ions in form of Titratable acids, ammonia (both of which each produce a new bicarb),
* Kidney also reabsorbs filtered bicarb

6

What is the major buffer in ECF?

Bicarb (HCO3-) (it binds w/ H+ acids)

7

What's the major buffer in ICF?

Phosphates (H2PO4), proteins

8

How does kidney hand le excess acids?

1. Reabsorption of filtered bicarb
2. Secretion of H+ ions via forming titratable acids and ammonium (which each produce a new bicarb)

9

How does kidney hand le excess acids?

FIRST: Reabsorption of filtered bicarb
THEN: Secretion of H+ ions via forming titratable acids and ammonium (which each produce a new bicarb)

10

Where does most of HCO3- reabsorption occur?

Proximal tubule

11

Where can HCO3- reabsorption occur?

Proximal tubule, distal tubule

12

Where can HCO3- reabsorption occur?

Proximal tubule (Na+/H+ and HCO3-Cl antiporter OR HCO3-Na symporter, distal tubule (K+/H+ and HCO3-Cl- antiporter OR HCO3-Na symporter)

13

The Kidney breaks down glutamine into what 2 products?

NH4+ and Bicarb

14

What's the net acid excretion equation?

Bases - Acids
= Bicarb - (Titratable Acids + NH4+)
= HCO3- - (TA + NH4+)

15

Is most excess acid is excreted as NH4+ or TA?

NH4+

16

How do you determine what causes acidosis or alkalosis? i.e. how do you know if its respiratory vs. metabolic?

1. pH: is it below 7.35 (acidosis) or above 7.45 (alkalosis)?
2. pCO2: if above 40 = acidic, if below 40 = alkalosis
3. HCO3-: if below 24 = acidosis, above 24 = alkalosis
4. Which matches the pH? that determines respiratory or metabolic!

17

If a disease/condition is recurrent, is it chronic or acute?

Chronic!

18

What's the normal range for anion gap?

8-12

19

What does an anion gap of 13 or more tell you?

likely an acidosis

20

If an individual has a normal anion gap, could it be causes by a base loss?

Yes! But, could NOT be caused by acid gain

21

What does anion gap tell you,
why do we calculate it?

whether acidosis is caused by acid gain or base loss

22

What's the most prevalent titratable acids inside of tubules?

Phosphates (mainly H2PO4) so secreted into lumen of tubules!

23

What is the liver product (AA) that is broken down to form ammonia?

Glutamine

24

What equation helps you decide whether acidosis is create from an acid gain or base loss?

Anion Gap

25

What's the typical plasma concentration of bicarb?

24 mm/L
Filtered Load = GFR x Px = 180 L/day * 24mm/L = 4320 mmol/day

26

What hormone increases Na+ reabsorption by increasing the # of H+/Na+ transporters in the Proximal Tubule?

Angiotensin II

27

What are 2 ways of reabsorbing the HCO3- across the basolateral membrane in the proximal tubule?

HCO3- Na+ SYMporter (Na+ & HCO3 go OUTSIDE cell)
HCO3- Cl- ANTIporter (Cl- goes INSIDE cell)

28

What's the major difference between Type A/alpha and Type B/beta intercalated cells in Distal Tubule?

They both have the same transporters but in Type A intercalated cells have K+ (in)/H+(out) exchanger/antiporter OR H+ pump on apical membrane and HCO3-/Cl- antiporter on basolateral membrane

In Type B = its vice versa where HCO3-/Cl antiporter is on apical membrane (so beta cells SECRETE HCO3-) and K+ (in)/H+ (out) antiporter OR H+ pump (ATP) is on basolateral membrane

29

Under what acid-base conditions are Type A intercalated cells active?

acidosis

30

Under what acid-base conditions are Type B intercalated cells active?

alkalosis

31

Do we have Na+/HCO3- symporters in distal tubule?

No! Only have Na+/Cl-

32

Where do we create and secrete ammonia?

Proximal tubule

To make ammonia from glutamine, takes a long time (delay) even though its UNLIMITED

33

Where do we create and secrete titratable acids?

Distal tubule

34

What are different causes of acid gain?

1. Decreased respiration (due to airway obstruction e.g. COPD, emphysema)
2. ketoacids (diabetes)
3. renal failure (bec/ kidneys can't secrete acids)
4. Diarrhea = Base loss

35

Diarrhea is a common cause of what condition?

Acidosis bec/ diarrhea is a base loss

36

What is the anion gap equation?

AG = Na - (Cl- + HCO3-)

37

Acid load acts as an unmeasured ______, unlike base loss bec/ when HCO3- lost, it's replaced by _______ . This is why Anion Gap is normal when we have a base loss.

anion, Cl-

38

Vomiting and/or hyperventilating cause what condition?

Alkalosis (it's a loss of fixed acid)

Alternatively, alkalosis can also be caused by base gain due to overdosing on base

39

What are the 2 processes by which the kidneys regulate plasma concentration of HCO3?

1. Reabsorbing filtered bicarb (HCO3-)
2. Producing new HCO3 by either forming and secreting Titratable acids or forming and secreting ammonium/ammonia

40

Do titratable acids change pH of the blood or urine?

NO! TAs are neutral molecules

41

Does Ammonium change the pH of blood or urine?

Yes

42

What is azotemia?

excess nitrogenous waste in urine

43

What is azotemia?

excess nitrogenous waste in blood

44

Is 16 breaths/min a normal respiratory rate?

Yes.
Range = 12-20

45

The higher the creatinine the lower the _____?

higher creatinine, lower GFR
bec/ creatinine is only filtered = so glomerulus is not working

46

The higher the creatinine the lower the _____?

higher creatinine, lower GFR
bec/ creatinine is only filtered = so glomerulus is not working if creatinine is high

47

How do you figure out GFR from plasma creatinine levels?

GFR = 1/Plasma Creatinine

48

How do you figure out GFR from plasma creatinine levels?

GFR = 1/[Plasma Creatinine]

49

If you go from laying down to standing up, what happens to your BP?

goes down (this is orthostatic hypotension)

50

Vomiting causes what conditions?

alkalosis due to acid loss (H+ and Cl-), so low Cl- levels (hypocholerima), dehydration due to volume loss (dehydration decreases GFR and increases creatinine levels)

51

What is indicated by loss of skin turgor and flat jugular veins?

Low BP due to low blood volume

52

During hypokalemia, what happens to K+ and H+ ions?

H+ ions pumped out, K+ ions pumped in

53

What are normal plasma Cl- levels?

105 mEq/L

54

What are normal plasma Na+ levels?

135-145 mEq/L

55

What are normal plasma K+ levels?

4 mEq/L