Pulm phys Flashcards
(48 cards)
what is flow proportional to
pressure gradient and inversly to radius
What is V0
dead space air
what is Va
air in aveoli
explain the beta agonists impact on beta 2
when NE binds- cascade of events leading to smooth muscle relaxation
-when we use beta agonist, radius increases and requires less pressure to get air flow
talk about cross sectional area
as cross sectional area increases, velocity slows down. velocity of air flow slow in alevoli which allow gas exhcnage to occur
what is ficks law of diffiusion
- looking at efficacy of gas exchange
ex: pt w pulm fib: tissue thickness= greater so diffiusion limited ability to exhchange O2 and Co2 is decreased
what is pH directly related to
- bicarbonate
- more bicarb could raise pH
- more co2 in body=more protons being released
do people with COPD retain co2?
yes which causes pH to fall
what is the conducting portion of the respiratory system
- “conditions” the inspired air
- bulk transport of air
- upper airway important for conditioning bc it warms air, filters large particles and saturates air with water vapor
what is the respiratory portion of the respiratory system
- gas exchange function
- everything conducting until respiratory bronchiole
- dead space: air flow but no gas exchange
where does the majority of gas exchange occur
alevolar sac and ducts
what is ventilation
the process by which air moves into and out of the lunges
how and why does ventilation occur
- pressure gradients move air: all you need is a small amount to allow for air flow to occur
- musculoskeletal pump allows this to occur
what is hyperventilation
blowing off co2
what is hypoventilation
retaining co2
does the entire “inspired” breath contribute to gas exhcange?
no.
-there is dead space
does the entire tidal volume contribute to gas exhcange
no
-thats why we have dead space and alevolar ventilation
what is the diff between hypoxia, hypoxemia and ischemia?
hypoxemia: low amount of o2 in blood
hypoxia: at tissue level
ischemia: lack of blood flow
what does the pulse ox on a finger measure
hypoxemia
explain dead space estimated by BW
if you took a breath thats the same amount as BW…not much gas exhcange would occur bc not overcoming dead space
-next to no alveolar ventilation
air will become 100% co2
does air go evenly through the lung when you take a breath?
no
talk about alveoli at rest
at rest, some are collapsed/not contributing to gas exhcnage
with exercise, they will participate=phyisiologic deadspace
what is minute ventilation
amount of air exhaled in one minute
what are the two componenets of ventilation
physiologic dead space: wasted ventilation
alveolar ventilation: gas exchange
