12. Acid-Base Balance And Blood Gases

Front 1

What are the 5 major buffer systems?

Back 1

1. Carbonic acid/Bicarb (plasma and cells)
2. Protein (plasma)
3. Hemoglobin (RBCs)
4. Phosphate (plasma/cells/urine)
5. Ammonia (urine)

Front 2

What buffer is the major extracellular buffer?

Back 2

Bicarb

Front 3

What buffer is the major intracellular?

Back 3

Hemoglobin

Front 4

-What protein is the main protein buffer?
-How does it buffer?

Back 4

Albumin; via the imidazole group of histidine

Front 5

Which buffers do/can buffer base?

Back 5

Bicarbonate and Phosphate

Front 6

What is the normal Base:acid ratio in the hh eqn?

Back 6

20:1

Front 7

Which component in the HH eqn reflects renal changes? Which reflects respiratory changes?

Back 7

Renal = top metabolic HCO3
Resp = lower respirty CO2

Front 8

In the bicarb buffer system:
-What shifts rxtn to left?
-What shifts rxtn to right?

Back 8

Left: increase in acid
Right: increase in base
(these are the body RESPONSES)

Front 9

What is INTERACTION REACTION?

Back 9

The term for when other conjugate bases act in concert with the bicarb sytem

Front 10

What detects changes in pCO2?

Back 10

-Chemoreceptors in medulla
-Aortic/carotid bodies

Front 11

How does respiration change in
-Metabolic acidosis?
-Metabolic alkalosis?

Back 11

Acidosis: increase respirations to blow off CO2
Alkalosis: depress respiratns to increase CO2

Front 12

What is the relationship between pO2 and pCO2?

Back 12

As PCO2 increases, pO2 decreases and vice versa

Front 13

What is the Bohr effect?

Back 13

Shifting of O2 diss. curve based on acid/base conditions.

Front 14

How does the Hb curve shift:
-in Acid?
-in Base?

Back 14

Acid: shift to right
Base: shift to left

Front 15

What is the Haldane effect?

Back 15

the effect of pCO2 on the Hb-O2 dissociation curve.

Front 16

How does the O2 diss curve shift with
-Increased CO2?
-Decreased CO2?

Back 16

Incr. CO2 = shift to right (acidosis)

Decr. CO2 = shift to left

Front 17

What happens to Hb's O2 affinity when curve shifts
-To the right?
-To the left?

Back 17

Right = decreased affinity - lose oxygen more easily
Left = increased affinity - harder to give oxygen to tissue

Front 18

How does CO2 enhance oxygen release from hemoglobin?

Back 18

By binding alpha amino groups of N-terminal valines on both Alpha and Beta chains

Front 19

How does 2,3-DPG enhance O2 release from hemoglobin?

Back 19

By binding alpha amino groups of N-terminal valines on ONLY Beta chains.

Front 20

On a Hb molecule:
-Where does O2 bind?
-Where does H+ bind?

Back 20

-O2 binds Iron group

-H+ binds imidazole group of histidine (similar to acid buffing by albumin)

Front 21

What is oxidized Hb bound to?
-Oxygen?
-Hydrogen?

Back 21

Hydrogen; oxygenated hemoglobin is not denoted as oxidized.

Front 22

What enzyme keeps hemoglobin in its reduced state?

Back 22

Methemoglobin reductase, which requires NADH

Front 23

What is the function of the ISOHYDRIC shift?

Back 23

To remove excess CO2 from the tissues after Hb delivers O2.

Front 24

What is the function of the Chloride shift?

Back 24

To maintain the RBC's electronegativity while buffering.

Front 25

How does the Isohydric shift work?

Back 25

1. O2 is delivered
2. CO2 diffuses into RBC
3. CO2 + H2O = H2CO3 = H+ and HCO3-
4. H+ binds naked Hgb
5. HCO3- diffuses out of RBC.

Front 26

How does the Chloride shift work?

Back 26

When HCO3 diffuses out of RBC, CL- diffuses in to balance the cell's ionic state.

Front 27

What pH state will produce
-Hyperkaluria?
-Hypokaluria?

Back 27

Hyper K+ from Acidosis

Hypo K+ from Alkalosis

Front 28

Where does bicarb reabsorption occur in the kidney?

Back 28

Proximal tubule

Front 29

Where does conjugate acid secretion take place in the kidney?

Back 29

-Distal tubule
(ammonia/phosphate)

Front 30

what is the pH limit of acidotic urine?

Back 30

4.5

Front 31

What 2 processes for H+ excretion occur in the distal tubule?

Back 31

-Ammonia
-Titratable acid - Phosphate

Front 32

What kidney response to Acid is:
-Immediate short term response
-Slow, long-term response?

Back 32

Immediate = Phosphate titratable acid.

Slow = Ammonium ion excretion

Front 33

What is the major indicator of a RESPIRATORY disturbance?

Back 33

PCo2

Front 34

What is the primary indicator of a METABOLIC disturbance?

Back 34

HCO3

Front 35

When is BE more off; in respiratory or metabolic disturbance?

Back 35

Metabolic;
Acidosis = --BE
Alkalosis = ++BE

Front 36

In what 3 conditions is resp alkalosis seen in?

Back 36

1. Hyperventilation
2. Salicylate toxicity
3. Cirrhosis

Front 37

In what 3 conditions is metabolic alkalosis seen in?

Back 37

1. Vomiting - K depletion
2. Diuretic long-term use
3. Cushing's disease

Front 38

In what 3 conditions is Resp acidosis seen?

Back 38

1. Central/peripheral resp failure
2. Emphesema
3. Barbiturate toxicity

Front 39

In what 3 conditions is Metab acidosis seen?

Back 39

1. Diabetic coma
2. Renal failure
3. Diarrhea w/ pyloric obstruction

Front 40

What is the treatment for Respiratory Acidosis?

Back 40

Increase respirations to blow off CO2

Front 41

What is treatment for Resp alkalosis?

Back 41

Breathe into bag to increase co2

Front 42

What is the treatment for Metabolic Acidosis?

Back 42

Give bicarb viat lactate/citrate ringers

Front 43

What is the treatment for Metabolic Alkalosis?

Back 43

Give salt - NaCl, KCl, or NH4Cl to acidify the kidney and induce loss of bicarb.