Mechanisms of Inspiration and Expiration Flashcards
in the normal breathing pattern, where does inspiration end
at the peak of the wave
in the normal breathing pattern, where does expiration end
at the trough of the wave
pressures at the end of a normal breath
atmospheric pressure = alveolar pressure
why does everything balance at the end of a normal breath
elastic recoil
elastic = having the property of returning to the original shape after being distorted
recoil = to spring back
what does the chest wall resist
inwards distortion from the resting position
means chest wall elastic recoil is outward
what are the equilibrium results in negative pleural pressure
lung elastic recoil inward = chest wall elastic recoil outward
how does gas get into the lungs
when atmospheric pressure is greater than alveolar pressure, gas moves down the pressure gradient into the lungs
diaphragm during inspiration
inspiratory neural activity from brain signals to diaphragm to expand to increase pleural space
external intercostal muscles during inspiration
elevate ribs to expand pleural space
inspiratory pressures
alveolar pressure < atmospheric pressure
how does air move from alveolus to atmosphere
atmospheric pressure < alveolar pressure
alveolar pressure decreases pushing air out
changes at end of normal breath in
no inspiratory neural activity
lung elastic recoil inwards
normal tidal expiration
passive process
alveolar pressure > atmospheric pressure
lung elastic recoil inward
pushes air out
recording of normal breathing pattern
inspiratory time < expiratory time
large/forced expiration
active process
internal intercostals contract - ribs depress
abdominal muscles contract
diaphragm contracts
