L24 - acid base balance

Question 1

venous and arterial blood have similar values of pH, conc of HCO3- and PCO2 but the venous is slightly higher than the arterial, why ?

Answer 1

venous tissues produce CO2 which then dissociates into H and HCO3-

Question 2

in terms of extracellular pH, what is H+ proportional and inversely proportional to

Answer 2

proportional to CO2 and inversely to pH

Question 3

during which processes where H- ions are produces

Answer 3

• ATPA hydrolysed
• anaerobic respiration
• ketones producrion
• ingestion of acids

Question 4

how is metabolically produced H+ removed

Answer 4

• reacts with HCO3 to becomes CO2 so it can be exhaled

- results a loss of HCO3 IONS -> low pH

Question 5

how do the kidneys play in the role of pH regulation and replaces loss of HCO3

Answer 5

-reabsorbs the filtered HCCO3 ions for buffering the pH

Question 6

how is HCO3 ions reabsorbed

Answer 6

CO2 produced from its ions and diffuse into the cell

• dissociates and the HCO3
• HCO3 exchanged out for Na ions

Question 7

how can HCO3 ions be produced in the cell in the nephron

Answer 7

CO diffused into cell from the cortical interstitial space

- dissociates and the HCO3 exchanged out into the cortical interstitial space for NA

Question 8

how can be H ions secreted into the filtrate from DCT

Answer 8

through apical H+K+ATPase and H+atpase

- occurs in the alpha intercalated cells in DCT

Question 9

how can be excess H ions be buffered in the filtrate

Answer 9

EQB between H+ and HPO42- to make H2PO4

-hydrogen phosphate is buffering the h

Question 10

what is another buffer for excess H

Answer 10

NH4+

-produced from PCT

Question 11

types of acid-base disorders

Answer 11

respiratory acidosis and alkalosis

metabolic acidosis and alkalosis

Question 12

what is respiratory acidosis

Answer 12

• due to hypoventilations
• CO2 levels goes up so shifts the EQB where H ions are produced
• for compensation, kidney increaases production of HCO3- so the pH returns to normal

Question 13

what is respiratory alkalosis

Answer 13

• high altitude or hyperventilation
• CO2 goes down so H goes down too
• kidney decreases HCO3- conc so the pH returns to normal

Question 14

what is metabolic acidosis

Answer 14

• renal failure, poisioning etc
• H goes up so HCO3- goes down or vice vera (pH decreases)
• ventilation rate increases to decrease CO2 so the pH returns to normal

Question 15

what is metabolic alkalosis

Answer 15

• vomiting etc
• H goes down so HCO3 goes up (pH rises)
• ventilation rate decreases so CO2 goes up
• pH returns to normal

Question 16

what is anoin gap

Answer 16

[Na]-[Cl]-[HCO3]

• appears to be more cations than anions but there are unmeasured anions
• • measurement of the difference-or gap-between the negatively charged and positively charged electrolytes
• if the anion gap is either too high or too low, it may be a sign of a disorder

Question 17

what does it mean if you have increases anoin gap

Answer 17

means high conc of anions so missing stuff like lactate, ketones