module 3 - 7.3 measuring the process of breathing Flashcards
what are the 2 mechanisms of ventilation?
- inspiration
- resting expiration
what happens during resting expiration?
- external intercostal relax - ribcage falls down and in
- diaphragm muscles relax - moves upwards
- volume of thoracic cavity decreases
- pressure of thoracic cavity increases
- air goes out of the lungs
why do we breathe out more H2O than we breathe in?
lungs are moist
how does the spirometer work?
- static lower half of tank full of water
- mobile upper half full of oxygen
- breathe out into tank - upper half rises
- tracer mark attached to mobile upper half
what does soda lime in a spirometer test for?
CO2
what happens to the trace when inspiring?
trace goes down (air out of machine and into lungs)
what happens to the trace when expiring?
traces goes up
what does the peak of expiration show?
volume of a single breath
why does the overall volume of gas decline over time?
- spirometer contains soda lime which absorbs CO2
- when breathing, we use oxygen from tank, as we breathe out, CO2 gets absorbed by soda lime
- gas volume then decreases over time
what do peak flow meters measure?
- rate that air can be expelled from the lungs
- measures air flow through the bronchi & degree of obstruction in airways
what is a vitalograph?
- a more complex version of peak flow meter
- produces a graph about amount of air breathed out and how quickly it happens
what is tidal volume?
the volume of air that moves into and out of the lungs with each resting breath
what is the vital capacity?
the largest volume of air that can be breathes in
- strongest exhale followed by strongest inhale
what is the inspiratory reserve volume?
the maximum volume of air you can breathe in ABOVE normal inhalation
what is the expiratory reserve volume?
maximum volume of air you can force out of your lungs over the normal tidal volume of air you breathe out
