Acid /Base 2-4 Godoy

Question 1

What 3 systems regulate H+ concentration and pH?

Answer 1

1. Buffer systems in the body (seconds)
2. Respiration- regulates CO2 (minutes)
3. Kidneys- excrete acids or bases (hours or days
   but very powerful)

Question 2

What is a buffer?

Answer 2

Substance that can bind H+ reversibly

Question 3

Give an example of an important hydration reaction we discussed.

Answer 3

CO2 + H2O H2CO3

Question 4

In tissue hypoxia (decrease O2) or ischemia, what pH would you expect?
A. More acidic
B. More basic
C. No change

Answer 4

More acidic, because lactic acid and waste will accumulate causing CO2 to increase

Question 5

What is the most important extracellular buffer?

Answer 5

Bicarbonate

Question 6

What does an open buffer system mean?

Answer 6

HCO3 and CO2 can be regulated

Question 7

Where is the phosphate buffer system important in?

Answer 7

In ICF and renal tubule fluid

Question 8

Where are protein buffers found?

Answer 8

Important buffers in both the intracellular and extracellular compartments

Question 9

T/F: Changes in the extracellular pH can change the intracellular pH.

Answer 9

True, because the cells are not isolated

Question 10

In erythrocytes, what is an important buffer system?

Answer 10

Hemoglobin buffer system

Question 11

How does hemoglobin bind to protons?

Answer 11

Has the amino acid histidine that contains imidazole groups

Question 12

Normal range of blood pH

Answer 12

7.35- 7.45

Question 13

What is a depression of pH below the normal range?

Answer 13

Acidemia

Question 14

What is alkalemia?

Answer 14

An elevation of pH above the normal range

Question 15

What is a disturbance caused by the addition of excess acid or removal of base from the ECF?

Answer 15

Acidosis

Question 16

What is alkalosis?

Answer 16

A disturbance caused by the addition of excess base

or the removal (loss) of acid from the ECF

Question 17

List some intracellular buffers.

Answer 17

Phosphate buffer, protein, hemoglobin buffer in rbc

Question 18

List some interstitial fluid buffers.

Answer 18

Bicarbonate buffer, phosphate buffer, protein buffer

Question 19

What is a buffer in the cerebrospinal fluid?

Answer 19

Bicarbonate buffer

Question 20

List some buffers in the tubular filtrate.

Answer 20

Bicarbonate buffer, phosphate buffer, ammonia

Question 21

List some buffers in the plasma.

Answer 21

Bicarbonate buffer, protein buffer, phosphate buffer

Question 22

Why does the body, in most circumstances, function as an open system?

Answer 22

So that pH changes are minimized

Question 23

What happens in tissue ischemia?

Answer 23

CO2 can’t be regulated, and builds up

Question 24

How can cells protect themselves against acid-base

disturbances?

Answer 24

Through the use of buffers and ion exchangers

Question 25

What happens if the pH in the cytosol decreases?

Answer 25

Activation of the Na/H exchanger

Cl/HCO3 activity will be inhibited

Question 26

What happens if the pH in the cytosol increases?

Answer 26

Activation of the Cl/HCO3 exchanger

Na/H activity will be inhibited

Question 27

What is another way the Henderson- Hasselbach equation can be viewed?

Answer 27

pH= 6.1 + log (renal function) / ventilation

Question 28

If the concentration of bicarbonate goes up, what happens to the pH?

Answer 28

Increases

Question 29

1st line of defense

Answer 29

Blood buffers, they cannot correct the problem

Question 30

2nd line of defense

Answer 30

Lungs, ventilation adjusts the pressure of CO2

Question 31

3rd line of defense

Answer 31

Kidneys, regulate bicarbonate concentration

Question 32

In the diagnosis of acid-base imbalances, a primary disorder that can change the blood pH is followed by?

Answer 32

A compensatory mechanism- either renal or respiratory

Question 33

What happens to CO2 and pH with hyperventilation?

Answer 33

CO2 decreases, pH increases (alkalosis)

Question 34

What happens to CO2 and pH with hypoventilation?

Answer 34

CO2 increases, pH decreases (acidosis)