exchange and transport Flashcards
what is meant by tidal volume
this is the volume of air that is breathed in or out during normal breathing (at rest)
what is meant by breathing rate
this is the number of breaths taken in one minute (one breath = taking air in and breathing it back out again)
what is meant by vital capacity
this is the maximum volume of air that can be breathed in or out in one breath
what is meant by oxygen uptake
this is the volume of oxygen used up by someone in a given time
outline how a spirometer works
- contains an oxygen filled chamber with a moveable lid
- person breathes through a tube connected to the oxygen chamber
- as person breathes in and out, the lid chamber moves up and down. - These movements are recorded by a pen attached to the lid of the chamber - it writes on a rotating drum, creating a spirometer trace.
From this trace, the subject’s vital capacity, tidal volume and breathing rate can all be calculated
why does the person using the spirometer have to wear a nose clip
so it is a closed system, all the oxygen comes from the machine
what is the use of a counterweight in spirometers
counterweight means there is no resistance so breathing in or out, without the counter balance the individual would have to be forcefully breathing out. would not be able to calculate tidal volume.
what is the point of the soda lime in the spirometer
soda lime absorbs the CO2 produced when breathing out
why does the spirometer trace go down over time
+ how can this information be used to calculate oxygen uptake.
Carbon dioxide is removed from the exhaled air, meaning that the total volume of air available in the spirometer gradually decreases, as oxygen is extracted from it by the subject’s breathing
This change in volume is used as a measure of oxygen uptake
why is there water in the spirometer system
to make an air tight seal and maintain a closed system.
apart from a traditional spirometer, what is another way changes in breathing can be measured and recorded
spirometer is hooked up to a motor sensor which produces electronic signals which are picked up by a data logger.
what is the small amount of air always retained in the lungs called, why does it exist
residual volume - due to cartilage in the trachea and bronchus, prevents collapsing.
on a spirometer graph, which way does the line go when the pps breathes in
upwards
