breathing mechanics Flashcards
what’s VE=TV x F?
minute ventilation=tidal volume x breathing frequency
what’s tidal volume?
volume of air inspired or expired per breath
what’s minute ventilation?
volume of air inspired or expired in one minute
why does VE rapidly increase at the start of exercise?
due to increase in breathing rate (BR) and TV
what’s tidal volume at rest?
500ml
what factors effect TV?
age, gender, size of lungs, fitness and respiratory conditions (asthma)
whats the breathing rate at maximal exercise?
50-60 breathes per min
what’s the thoracic cavity?
area of space enclosed by ribs and diaphragm
what muscles are required for inspiration at rest?
diaphragm, external intercostals
what muscles are required for inspiration during exercise?
diaphragm, external intercostals, sternocleidomastoid, pectoralis minor, scalenes
how does expiration happen at rest?
relies on gravity mainly and muscles relax to decrease thoracic cavity
what muscles are contracted during expiration at rest?
internal intercostals, diaphragm (with more force), obliques, rectus abdominus
why is air forced out of the lungs?
increase pressure inside lungs forces air out into less pressured area (surrounding air)
why is air forced into the lungs?
pressure inside lungs is lower than outside air rushes in to even pressure gradient
what controls respiration?
RCC split into inspiratory and expiratory centers
