111114 chem control of breathing

Question 1

how can body respond to changes in O2 and CO2?

Answer 1

breathing frequency and tidal volume

Question 2

end tidal volume

Answer 2

also called alveolar CO2 and alveolar O2

Question 3

what happened to PETO2 with inhaling a CO2 enriched gas mixture?

Answer 3

it increased even though inspired O2 decreased

Question 4

what happened to PETCO2 with inhaling a CO2 enriched gas mixture?

Answer 4

it increased

Question 5

what happened to total ventilation with inhaling a CO2 enriched gas mixture?

Answer 5

increased, but slowly (suggests it must be brain intracranial chemoreceptor and not carotid)

Question 6

why did PETCO2 and PETO2 increase when breathing the CO2 enriched mixture?

Answer 6

b/c he was breathing more

Question 7

what was the subject’s hydrogen ion status during CO2 breathing?

Answer 7

pCO2 went up by 10

pH dropped from 7.4 to 7.3

Question 8

what are the effects on breathing and plasma hydrogen ion concentration of chronic alveolar hypoventilation?

Answer 8

loss of sensitivity to CO2

Question 9

when breathing hypoxic gas mixture, why happened to PETCO2 and PETO2?

Answer 9

decreased b/c he’s breathing hypoxic gas and b/c he’s hyperventilating

Question 10

difference in ventilation between breathing CO2 enriched mixture and breathing hypoxic mixture?

Answer 10

breathing increases much more for the CO2 enriched mixture even thouh CO2 didn’t go up nearly as much as oxygen went down in the hypoxic case. This tells us that within physiological range, O2 sensors aren’t that sensitive. But CO2 receptors-those primarily in brain-are highly sensitive

Question 11

subject’s pH during hypoxia?

Answer 11

7.5

respiratory alkalosis