2.5 Alveolar gas exchange conceptual Flashcards
What is the equation that dictates how much the resistance of the airways can change
R=(8nL/r^4)
True/False: The radius has the greatest impact on the resistance of the airway
True
When a parasympathetic response is initiated, describe what happens in the pulmonary system
Smooth muscle contractions: constrict airways and the blood vessels by changing the RADIUS
Ventilation will decrease
Perfusion will decrease
What is the equation for the ventilation?
VA(dot)=VA xF
***4L/min is the average
What is the average perfusion?
5L/min
How does the fact that the diffusion coefficient for CO2 is higher than that of O2 effect the overall amount that is exchanged each minute
CO2 is able to diffuse FASTER; more water soluble
***Could be one of the reasons that people with SEVERE and chronic lung diseases have to be VERY bad before they notice any changes in the CO2 concentrations
Why is the pressure gradient for oxygen positive and the gradient for CO2 negative?
Because you want the oxygen to go IN and the CO2 to go OUT
As surface area increases, J ________
increases
Why do people with COPD or emphysema have a hard time getting sufficient oxygen into their systems?
Because of the decreased surface area
Describe why having an increase in the distance of diffusion will decrease J
J is the rate that the diffusion occurs; increasing the distance that has to be travelled will decrease the rate of diffusion because the gasses have to go farther
The deposition of _______ is seen in interstitial lung disease
collagen
What is the equation for LaPlaces law?
2T/r
***T=tension
Describe the role of surfactant in the alveoli
The surfactant decreases the pressure gradient that the air moves down, and decreases the pressure of the smaller alveoli, this allows for all of the larger alveoli to ALSO receive the air (higher priority) so that gas exchange is able to occur.
reduces the T in the smaller alveoli
