acid base

Question 1

what is the principal extracellular buff system

Answer 1

carbonic acid/ bicarbonate (H2CO3/HCO3) system

Question 2

what are examples of 3 physiologic buffers

Answer 2

1. plasma proteins
2. hemoglobin
3. phosphate

Question 3

what regulates bicarbonate in carboinic acid/bicarb buffer system

Answer 3

kidneys

Question 4

why is the carbonic acid/bicarb buffer the most important buffer system in the body

Answer 4

1. more bicarbonate in the ECF than any other buff
2. unlimited supply of CO2
3. defree of ECF acidity can be regulated by changing HCO3- and/ pCO2

Question 5

what is the respiratory component of carbonic acid/bicarb buffer

Answer 5

carbonic acid

Question 6

what is the metabolic component of the carbonic acid/bicarb buffer system

Answer 6

bicarbonate (HCO3-)

Question 7

what is the respiratory component of the carbonic acid/bicarb buffer system equation

Answer 7

CO2 + H2O

Question 8

how is bircarbonate reported clinically in an electrolyte panel?

Answer 8

serum CO2

Question 9

what sense changes in pCO2 and H+ concentrations and modulate the control of breathing?

Answer 9

medullary chemoreceptors in the brain

Question 10

what is regulated renally in the carbonic acid/bicarb buffer system?

Answer 10

1. excretion of acid (H+)
2. reabsorption of filtered HCO3-
3. regeneration of bicarbonate

Question 11

how much bicarb is delivered to the nephron daily

Answer 11

~4500 mEq HCO3-

Question 12

where is bicarbonate freely filtered

Answer 12

glomerulus

Question 13

where does 90% of bicarbonate reabsorption occur?

Answer 13

proximal tubule

Question 14

what catalyzes the reabsorption of carbonic anhydrase

Answer 14

carbonic anhydrase

Question 15

where doe remaining H+ secretion occur after having been reabsorbed via carbonic anhydrase

Answer 15

distal tubule

Question 16

If your primary disorder is respiratory, compensation will take place with what?

Answer 16

kidneys compensate by adjusting bicarb elimination

Question 17

If your primary disorder is metabolic, compensation will take place with what?

Answer 17

lungs will compensate by adjusting CO2 elimination

Question 18

what are the 3 major components of assessing acid base statue

Answer 18

1. blood gas
2. serum electrolytes
3. medication and medical history

Question 19

what are serum electrolytes useful for when assessing acid base status

Answer 19

delineating respiratory vs. metabolic disorders

Question 20

what is the most important diagnositic test for acid bace status

Answer 20

arterial blood gas

Question 21

what is caused by decreased serum HCO3- concentration, resulting in decreased pH

Answer 21

metabolic acidosis

Question 22

what are 3 things that can result in metabolic acidosis

Answer 22

1. diarrhea = increased elimination of HCO3- stores
2. renal failure = decreased elimination of org. acids
3. lactic acid = increased production of organic acids

Question 23

what occurs from accumulation of anions that result from consumption of HCO3 by endogenous organic acids or toxin ingestion

Answer 23

increased anion gap

Question 24

what are 4 common causes of elevated anion gaps

Answer 24

1. renal failure
2. ketoacidosis
3. lactic acidosis
4. intoxications