25 Acid-Base Homeostasis and Imbalance

Question 1

death range of pH

Answer 1

too acidic<6.9-7.8

Question 2

maintenance of acid-base balance reflects homeostatic functions of ___

Answer 2

normal cellular metabolism

Question 3

if pH is too acidic, proteins will ____

Answer 3

get denatured

Question 4

normal pH

Answer 4

7.35-7.45

Question 5

normal PaCO2

Answer 5

36-44 mmHg

Question 6

normal HCO3-

Answer 6

22-26 mEq/L

Question 7

useful indicators of acid-base status of ECF

Answer 7

arterial blood gas [ABG]

Question 8

PaCO3 indicates ___

Answer 8

how effectively the respiratory sytm is excreting carbonic acid

lung/respiratory function

Question 9

HCO3- indicates ___

Answer 9

effectiveness of renal regulation of metabolic acids

• excess or deficit of metabolic acids
• renal/metbolic function

Question 10

3 major systems to regulate acid-base

Answer 10

1 buffer
2 respiratory sytm
3 renal sytm

Question 11

compensatory mechanisms to regulate acid-base

Answer 11

respiratory + renal system

Question 12

first line of defense against pH changes in all body fluids

Answer 12

Bicarbonate Buffer system

Question 13

chemicals that help control pH of body fluids

Answer 13

1 Bicarbonate ions [HCO3-]

2 Carbonic acid [H2CO3]

Question 14

Bicarbonate Ions

Answer 14

HCO3-
basic
-takes up H when fluid is too acidic

Question 15

Carbonic Acid

Answer 15

H2CO3
weak acid
-release H ions when fluid is too alkaline

Question 16

types of buffers

Answer 16

1 bicarbonate buffers
2 phosphate buffers
3 hemoglobin buffers
4 protein buffers

Question 17

bicarbonate buffer system RXN

Answer 17

H2O + CO2 <> H2CO3 <> H+ + HCO3-

Question 18

bicarbonate buffer system

Answer 18

primary defense against acid-base disorders

-most important buffer in ECF

Question 19

when body fluid is acidic, H+ is high >

Answer 19

H+ + HCO3- > H2CO3 > H2O + CO2 > exhale CO2

Question 20

when body fluid is alkaline, H+ is low >

Answer 20

H2CO3 > H+ HCO3-

Question 21

NonVolatile Acids

Answer 21

lactic acid, acetoacetic acid, keto acid

Question 22

the lungs can excrete ____ acid only

Answer 22

the lungs can excrete CARBONIC ACID only;

the CANNOT excrete nonvolatile acids

Question 23

Volatile Acid

Answer 23

carbonic acid

Question 24

Respiratory Acidosis

Answer 24

INCR PaCO2; DECR pH

-condition that cause excess of carbonic acid

Question 25

Respiratory Acidosis | respiratory response

Answer 25

hyperventilation CORRECTS imbalance | -excretes CO2

Question 26

Respiratory Alkalosis

Answer 26

DECR PaCO2; INCR pH

Question 27

Respiratory Alkalosis | respiratory response

Answer 27

hypoventilation CORRECTS imbalance | bc decr O2, incr retention of CO2

Question 28

Metabolic Acidosis

Answer 28

DECR pH fr excess metabolic acids

Question 29

Metabolic Acidosis | respiratory response

Answer 29

hyperventilation COMPENSATES imbalance

Question 30

Metabolic Alkalosis

Answer 30

INCR pH fr deficit of metabolic acids

Question 31

Metabolic Alkalosis | respiratory response

Answer 31

hypoventilation COMPENSATES for imbalance

Question 32

respiratory response to metabolic acidosis/alkalosis can only COMPENSATE for pH imbalance because...

Answer 32

respiratory can only excrete carbonic acid, NOT metabolic acids (nonvolatile acids)

Question 33

carbonic acid is solely excreted by

Answer 33

the lungs

Question 34

kidneys can excrete ____ acid from the body except ____ acid

Answer 34

kidneys can excrete ANY acid except CARBONIC acid

Question 35

which organ excretes metabolic acid?

Answer 35

kidneys

Question 36

Kidneys can COMPENSATE for respiratory pH imbalance aka carbonic acid excess/deficit. However, the kidneys require ____

Answer 36

several days to be fully operative.

Question 37

INCREASED HCO3-

Answer 37

indicates deficit of metabolic acids

Question 38

INCREASED HCO3-

Answer 38

indicates deficit of metabolic acids

Question 39

how do kidneys compensate for excess/deficit of carbonic acid [H2CO3-]?

Answer 39

EXCSS: excrete metab acid + H+ DFCT: excrete HCO3- (bicarbonate) decrease excretion of metab acid + H+

Question 40

4 primary acid-base disorders

Answer 40

1 Respiratory Acidosis 2 Respiratory Alkalosis 3 Metabolic Acidosis 4 Metabolic Alkalosis

Question 41

Respiratory Acidosis | cause

Answer 41

caused by impaired removal of carbonic acid by lungs - impaired gas exchange - inadequate neuromuscular function - impairment of respiratory control in brainstem

Question 42

examples of impaired gas exchange that can cause resp.acid.

Answer 42

``` 1 COPD 2 Pneumonia 3 Severe Asthma 4 Pulmonary Edema 5 ARDS ```

Question 43

examples of inadequate neuromuscular function that can cause resp.acid.

Answer 43

``` 1 guillain-carre syndrom 2 chest injury/surgery (pain limits breathing) 3 hypokalemic resp muscle weakness 4 severe kyphoscoliosis 5 resp muscle fatigue ```

Question 44

examples of impaired resp control (brainstem) that can cause resp.acidosis

Answer 44

respiratory-depressant drugs like opioids or barbiturates

Question 45

Respiratoy Alkalosis | cause

Answer 45

carbonic acid deficit is usually caused by hyperventilation | bc gets rids of CO2

Question 46

what causes hyperventilation which can cause resp.alka.

Answer 46

``` 1 hypoxemia 2 acute pain 3 anxiety, psych stress 4 prolonged sobbing 5 alcohol withdrawal 6 stim of brainstem ```

Question 47

relative excess of any acid except carbonic acid is ___

Answer 47

Metabolic Acidosis

Question 48

normal ratio of HCO3-:H2CO3

Answer 48

20:1

Question 49

how is normal ratio of bicarbonate (hco3-) decreased to carbonic acid (h2co3)

Answer 49

bicarbonate ions are used up in buffering excess acid

Question 50

Starvation Ketosis

Answer 50

bicarbonates get used up to buffer excess acid; causes decrease in normal bicarb to carb.acid ratio

Question 51

Starvation Ketosis | cause

Answer 51

1 caloric + glucose intake is insufficient 2 body begins to use fat stores for energy 3 fat metab incompletely 4 ketoacids accumulate in blood, causing METAB.ACIDOSIS

Question 52

excess removal or decrease in base is ____

Answer 52

metab acidosis

Question 53

Metabolic Acidosis

Answer 53

-relative excess of any acid except carbonic acid or -excess removal or decrease in base (bicarbonate)

Question 54

examples of excess removal of base that cause metab. acidosis

Answer 54

diarrhea | -loss of intestinal fluid that is rich in bicarbonate that originates fr pancreatic secretion

Question 55

hyperkalemia

Answer 55

high potassium; | metabolic acidosis

Question 56

metab alkalosis/decrease ina cid | clinical manifestations

Answer 56

``` 1 emesis (vomit) 2 hyperaldosteronism (decr in K, retention of Na + H2O) 3 hypokalemia (low K) ```