Ch. 11 ventilation Flashcards
What is the primary function of lungs
Supply the body with oxygen and remove carbine dioxide aka gas exchange
Ventilation vs respiration
Ventilation: process of moving gas in and out of lungs. Cyclic
Respiration: physiologic processes of oxygen use at the cellular level
Tidal volume
Volume of gas measured during normal inspiration and expiration
In order to ventilate, the respiratory muscles must generate changes in ___ _____ so that gas will flow in and out of lungs
Pressure gradient
Elastance vs compliance vs resistance formulas
Elastance: P/V
Compliance: V/P
Resistance: P/V•
What is pressure gradient
Pressure difference among gases, gas moves due to pressure gradient
Transrespiratory pressure PTR
Allows for actual gas flow in and out of long
PTR= PAO-PBS
Transpulmonary pressure difference PTP
Maintains alveolar inflation
PTP= PAO-Ppl
Ppl remains negative ( aka sub atmospheric) during quiet breathing
At the beginning of normal inspiration, what widens and is less than PAO
The transpulmonary PG ( pressure gradient) widens and the Palv is less than PAO
At the beginning of normal expiration, what flows out
Gas flows out because the Palv is now greater than PAO
A difference in pressure gradients (PG) must
Exist between alveoli and capillaries
Pressure gradients describe the movement of what
Gas between lungs and body tissues aka gas diffusion
A decrease in surfactant will significantly oppose what
Lung inflation
What is hysteresis
Difference between inspiratory lung volumes and expiratory lung volume
What is Elastance
Natural ability to stretch and return to original shape
