Sequence of events Flashcards
describe how pathologies that can alter these events
emphysema: destruction causes reduced elasticity & air trapping occurs (hyperinflation). Also diaphragm fatigues
Asthma: bronchospasm causes increase airflow resistance and decreased airflow
Cystic fibrosis/ chronic bronchitis: excess secretions reduce airflow into alveoli.
Atelectasis: WOB is increased to inflate collapsed airways
State the sequence events of inhalation & exhalation
RCC initiates breath
Inspiratory muscles begin to contract
Diaphragm flattens and increases vertical diameter
Thorax moves out (bucket) & up (pump)
Intrapulmonary volume increases/ pressure decreases
Interpleural volume increases/ pressure decreases
Intrapulmonary pressure becomes more negative than atmosphere
air moves down concentration gradient until equilibrium
air movement stops
RCC ceases inspiration
inspiratory muscles relax
diaphragm recoils to original position
thorax moves down & in
lungs elastically recoil
interpulmonary volume decreases/ pressure increases
intrapleural volume decreases/ pressure increases
air is forced out of the lungs
air movement stops
