Chapter 17 Study Questions (Pt. 1) Flashcards
why do we breathe in?
need O2
why do we breathe out?
remove CO2
how is COPD primarily treated? why?
glucocorticoids. suppress inflammation
what is the idea behind the approach of a low respiratory quotient diet?
COPD = limited lung capacity
minimizing RQ means minimizing lung effort by getting calories from fat metabolism
what is the respiratory quotient?
ratio of CO2 produced to O2 consumed
how is atmospheric pressure created?
air has mass and presses down on whatever is underneath it
what is partial pressure
individual pressure of each gas in a mixture
how do you calculate the partial pressure for a particular gas in air? can you give an example?
Ppartial = air/atms pressure * % of that air
ex. N2 makes up 79% of air, air pressure = 760 mmHg
PN2 = 760(.79) = 600 mmHg
what is humidity
amount of water vapor in the air
how does humidity affect gas partial pressure? why?
increased humidity decreases partial pressure.
more water vapor in the air = more gasses = each gas occupies less % = decrease in partial pressure
how does altitude affect gas partial pressure? why?
increased altitude = less air above you to exert pressure = decreased total air pressure (low P = high V) = decreased partial pressure
what effect does altitude have on the percentage of each gas in the atmosphere
% of each gas remains the same (ratios)
amount of each gas in the air decreases
why is the alveolar PO2 and PCO2 so much different from atmospheric values?
chart
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?
- 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
at equilibrium how would you describe the movement of a given gas molecule across a gas/liquid interface?
no net movement
at equilibrium, how would you describe the relative concentration of O2 at a alveolar air space/plasma interface/
AAS: high O2 conc
P: low O2 conc
at equilibrium, how would you describe the relative concentration of CO2 at a alveolar air space/plasma interface?
AAS: low CO2 conc
P: high CO2 conc
how is the O2 conc gradient maintained as oxygen moves from: the atmosphere to alveoli
O2 moves passively down conc gradient
how is the O2 conc gradient maintained as oxygen moves from: the alveoli to plasma, then to RBCs
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
how is the O2 conc gradient maintained as oxygen moves from: RBCs to plasma then to tissue (cells)
in RBCs, O2 becomes oxyhemoglobin
oxyhemoglobin diffuses into plasma, poor solubility, and into cells
how is the O2 conc gradient maintained as oxygen moves from: cell to mitochondria
diffuses to mitochondria, releases oxygen, where oxygen becomes H2O
