Chapter 17 Study Questions (Pt. 1)

Question 1

why do we breathe in?

Answer 1

need O2

Question 2

why do we breathe out?

Answer 2

remove CO2

Question 3

how is COPD primarily treated? why?

Answer 3

glucocorticoids. suppress inflammation

Question 4

what is the idea behind the approach of a low respiratory quotient diet?

Answer 4

COPD = limited lung capacity

minimizing RQ means minimizing lung effort by getting calories from fat metabolism

Question 5

what is the respiratory quotient?

Answer 5

ratio of CO2 produced to O2 consumed

Question 6

how is atmospheric pressure created?

Answer 6

air has mass and presses down on whatever is underneath it

Question 7

what is partial pressure

Answer 7

individual pressure of each gas in a mixture

Question 8

how do you calculate the partial pressure for a particular gas in air? can you give an example?

Answer 8

Ppartial = air/atms pressure * % of that air

ex. N2 makes up 79% of air, air pressure = 760 mmHg

PN2 = 760(.79) = 600 mmHg

Question 9

what is humidity

Answer 9

amount of water vapor in the air

Question 10

how does humidity affect gas partial pressure? why?

Answer 10

increased humidity decreases partial pressure.

more water vapor in the air = more gasses = each gas occupies less % = decrease in partial pressure

Question 11

how does altitude affect gas partial pressure? why?

Answer 11

increased altitude = less air above you to exert pressure = decreased total air pressure (low P = high V) = decreased partial pressure

Question 12

what effect does altitude have on the percentage of each gas in the atmosphere

Answer 12

% of each gas remains the same (ratios)

amount of each gas in the air decreases

Question 13

why is the alveolar PO2 and PCO2 so much different from atmospheric values?

Answer 13

chart

Question 14

what is spent air? (4)

where does it remain at the end of an exhale?
what is it depleted of?
what does it have a lot of?
effect on gradient?

Answer 14

• remains in the alveolar air space at the end of an exhale
• depleted of O2
• a lot of CO2
• ensures that there is an O2 concentration gradient between atmospheric and alveolar air

Question 15

at equilibrium how would you describe the movement of a given gas molecule across a gas/liquid interface?

Answer 15

no net movement

Question 16

at equilibrium, how would you describe the relative concentration of O2 at a alveolar air space/plasma interface/

Answer 16

AAS: high O2 conc

P: low O2 conc

Question 17

at equilibrium, how would you describe the relative concentration of CO2 at a alveolar air space/plasma interface?

Answer 17

AAS: low CO2 conc

P: high CO2 conc

Question 18

how is the O2 conc gradient maintained as oxygen moves from: the atmosphere to alveoli

Answer 18

O2 moves passively down conc gradient

Question 19

how is the O2 conc gradient maintained as oxygen moves from: the alveoli to plasma, then to RBCs

Answer 19

conc gradient from Alv to plasma

in plasma, there is poor solubility, meaning plasma can’t hold O2 that won’t dissolve, and O2 moves into RBCs

Question 20

how is the O2 conc gradient maintained as oxygen moves from: RBCs to plasma then to tissue (cells)

Answer 20

in RBCs, O2 becomes oxyhemoglobin

oxyhemoglobin diffuses into plasma, poor solubility, and into cells

Question 21

how is the O2 conc gradient maintained as oxygen moves from: cell to mitochondria

Answer 21

diffuses to mitochondria, releases oxygen, where oxygen becomes H2O