breathing dynamics and lung volume Flashcards
exerted by gas molecules in environment,
at sea level = 1
1 atm = 760 mm Hg
Atmospheric pressure (Patm)
air pressure in lungs
Alveolar pressure (Pav)
pressure between pleural layers ~ 756 mmHg
Intrapleural (intrathoracic) pressure (Pip)
what holds alveolus partially open (not completely deflated)
Intrapleural (intrathoracic) pressure
During inspiration, the diaphragm contracts and size of thoracic cavity (increases/decreases), this changes intrapleural pressure to (greater/less) than atmospheric.
increases
less
During inspiration, lungs expand as they are pulled by cavity expansion, this (increases/decreases) alveolar pressure to (less/greater) than atmospheric.
decreases
less
What is another word for pressure?
concentration
Inspiration establishes atmospheric and alveolar pressure difference so air flows _________ alveoli
(P__ > P__)
into
Patm > Palv
During expiration, the body turns ___ nervous signal to relax diaphragm/ external intercostals
off
During expiration, the thoracic cavity decreases in size causing intrapleural pressure to ___.
increase
During expiration, the decrease in thoracic cavity size squeezes lungs causing them elevate alveolar pressure greater than
___.
atmospheric pressure
During expiration, the pressure gradient moves air __ of lungs (P__<P__)
out
Patm < Palv
reflexes based on irritants, CO2 levels
What controls these actions?
coughing, yawning
medulla
1 inspiration and 1 expiration
ventilation
Rate and volumes of ventilation are measured via ____.
spirometry
