renal 7

Question 1

What is the normal pH of the blood

Answer 1

7.4

Question 2

describe how ventilation rate (and thus PO2) changes with changes in pH

Answer 2

Decreased pH increases ventilation to try and blow off excess CO2

Question 3

define respiratory acidosis

Answer 3

not enough CO2 blown off

- lowered breathing rate

Question 4

define respiratory alkalosis

Answer 4

too much CO2 blown off

- increased breathing rate

Question 5

metabolic acidosis

Answer 5

too acidic

- can’t be eliminated by respiration

Question 6

metabolic alkalosis

Answer 6

too basic

- can’t be eliminated by respiration

Question 7

acidemia

Answer 7

process of lowering pH

Question 8

alkalemia

Answer 8

process of raising pH

Question 9

how does the kidney compensate for metabolic acidosis or alkalosis

Answer 9

• responds to alkalosis by excreting alkaline urine high in HCO3
• responds to acidosis by excreting acidic urine, and kidney reabsorbs all the bicarbonate

Question 10

describe the effect of a chemical buffer when a strong acid or strong base is added to a body fluid

Answer 10

• Buffer can reversibly bind H+
• when blood is acidic, buffer binds to H+ as long as buffer is available to keep pH in check
• IF pH is LOW, the buffer releases from H+ to keep the pH in check

Question 11

where is the bicarbonate buffer system used?

Answer 11

• used in ECF
• HCO3 binds free H+
• catalyzed by carbonic anhydrase

Question 12

where is the phosphate buffer system used?

Answer 12

• used in urine and ICF

- phosphate is low in ECF

Question 13

where is the protein buffer system used

Answer 13

• used in ICF, hemoglobin and plasma are buffering agents

- amounts of proteins don’t change in response to stimulus so not part of normal compensatory response

Question 14

where is ammonia buffer system used?

Answer 14

body’s major adaptive response to acid load

Question 15

describe bicarbonate reabsorption

Answer 15

• fluid in lumen contains HCO3
• active secretion of H+ into lumen causes HCO3–> H2CO3 and then forms –> CO2 and H20
• CO2 diffuses into renal tubule cell where it combines with H20 to makemore H2CO3 which breaks down into HCO3 and H+
• HCO3 then moves down concentration gradient across basolateral membrane via carrier mediated diffusion

Question 16

describe how bicarbonate reabsorption can compensate for acidosis

Answer 16

• The H+ secreted becomes H2O which is excreted
• compensates for acidosis by reabsorbing all or most of the HCO3
• opposite compensation for alkalosis

Question 17

describe phosphate buffering in respiratory acidosis

Answer 17

• secreted H+ binds to available phosphate (NaHPO4-) and is excreted

Question 18

describe glutamine-NH4+ buffering in severe respiratory acidosis

Answer 18

• If all of the HCO3 is reabsorbed and used up all the phosphate and is STILL ACIDIC… the glutamine-NH4+ system can be used
• IN PROXIMAL TUBULE, glutamine can be metabolized to bicarbonate (which is added to blood) and ammonium ion which is secreted and excreted