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
normal, resting breathing
How many mL’s
tidal volume
500mL
volumed inspired beyond tidal volume
mL’s?
inspiratory reserve volume
3000mL
volume expired beyond reserve volume
mL’s?
expiratory reserve volume
1100mL
remainder volume in lungs
mL’s
residual volume
1200mL
sum of tidal, reserves, and residual volumes
total lung capacity
5-6L total
