Physical Aspects of Breathing Flashcards
what is the respiratory quotient?
co2 produced over oxygen consumed
what is the respiratory quotient on carb diet?
1.0
what is the respiartory quotient for fat diet?
0.7
what is the respiratory quotient for mixed carb and fat diet?
0.8
what is the partial pressure of oxygen and percent oxygen in dry air?
160 or 21%
what is the partial pressure of oxygen in moist tracheal gas? explain this
150…lower because of presence of water in air takes away place for oxygen so taking 21% of smaller number
what is the partial pressure of oxygen in alveoli? explain
104 mmHg about…this is because you are getting higher amounts of CO2 so less space for O2 to reside…drives it down…H20 still present too
what is the partial pressure of carbon dioxide in the alveoli?
40 mmHg
what does it mean for the conducting zone to be an anatomic dead space?
it means it cannot contribute to gas exchange
does cross sectional area increase or decrease as you move down the respiratory tract?
Def increases
explain how air comes into the lungs using boyles law?
pressureXvolume=constant….so as you increase volume pressure drops and air flows in
is there a negative or positive pressure in the intrapleural space?
negative pressure…
why is there negative pressure in the pleural space?
because the fluid lubricating the space creates a vacuum with the two layers trying to pull apart…visceral pulling in as lung wants to collapse and chest parietal layer wants to expand
is a highly compliant lung floppy or stiff?
floppy
is a high elastance lung floppy or stiff?
stiff
what process drives expiration?
passive elastic recoil of the lungs
if you need to know the residual volume of someones lungs, what test can you do?
body plethysmograph
what are the three categories of lung disease?
developmental
restrictive
obstructive
is CF an obstructive or restrictive lung disease?
obstructive
is emphysema an obstructive or restrictive disease?
obstructive
what is the intrapleural pressure at the end of expiration?
-5 cmH20
what is the intrapleural pressure during inspiration?
-8 cmH20
why does the intrapleural pressure drop more during inspiration?
because the respiratory muscles are pulling the chest wall out and lung still has recoil force…so creates bigger vacuum
how do you calculate the transmural or transpulmonary pressure?
alveolar pressure minus the intrepleural pressure
mathematically define the compliance of a lung
change in volume over change in pressure
how does elastance of a lung relate to compliance of a lung?
elastance is the mathematical inverse of the compliance of the lung
define the inspiratory reserve volume
volume of air you can add in addition to a normal breath
define tidal volume
volume of normal breath
define expiratory reserve volume
volume of air that can be forced out with a hard force
define residual volume
volume of air left in lungs after the expiratory reserve volume has been pushed out
name the three lung volumes that add up to vital capacity
expiratory reserve
tidal
inspiratory reserve
name the four lung volumes that add up to total lung capacity
tidal
expiratory reserve
inspiratory reserve
residual
name the two lung volumes that add up to inspiratory capacity
tidal
inspiratory reserve
name the two lung volumes that add up to functional residual capacity
expiratory reserve
residual volume
describe restrictive lung disease in terms of elastance or compliance
restrictive lung disease is seen in lungs that have very high elastance, or very low compliance
describe obstructive lung disease in terms of elastance or compliance
obstructive lung disease is seen in lungs with very low elastance or very high compliance
what is normal ABG for oxygen?
80-100 mmHg
what is normal ABG for CO2?
35-45 mmHg
