Lecture 8 - The respiratory cycle Flashcards
what is interpleural pressure
pressure between the two pleura of lungs; typically -5 cm H2O at rest; -8 after inspiration
what is alveolar pressure
pressure inside alveoli; or PA; at end of inspiration PA is -1 cm H20 due to increase in alveolar size and air now enters lungs
what is anatomic dead space
the space in the anatomy of the lungs that doesn’t handle respiration (conducting portion)
what is alveolar ventilation
the (tidal volume - dead space)*RR or the amount of gas that actually reaches the alveoli
what is minute ventilation
the Vt*RR or the amount of air cycled per min
what is transpulmonary pressure
the difference between alveolar pressure (P_A) and pleural pressure (P_PL)
what is the percentage of O2 in the air
21%
what is partial pressure or P of a gas
amount of gas in relation to others
What is Q or Q dot
blood flow
What is V or volume
volume of gas
what is tidal volume
the volume per average breath
What is V dot
airblow or volume per unit time
what is F
fractional concentration of gas. no units
what is barometric pressure in cm H2O
760 mm Hg = 0 cm H2O
When are lungs most prone to collapse?
inspiration; surfactant keeps them from doing this
Describe the volume change in the lungs during insp/exp
Describe the change in alveolar pressure during insp/exp
Describe intrapleural pressure during insp/exp
Describe air flow during insp/exp
