Exchange Surfaces - Lung Volumes Flashcards
define tidal volume
the volume of air moved in and out of the lungs with each breath when you are at rest
define vital capacity
the largest possible volume of air that can be moved into and out of the lungs in one breath
define inspiratory reserve volume
how much more air can be breathed in over and above tidal volume
define expiratory reserve volume
how much more air can be breathed out over and above tidal volume
what is the formula for vital capacity
tidal volume + inspiratory reserve volume + expiratory reserve volume
define residual volume
the volume of air that always remains in the lungs, even after the biggest possible exhalation
define dead space
the air in the bronchioles, bronchi and trachea. there is no gas exchange between this air and the blood
how does a spirometer work
as the person breathes out, the volume of air inside the chamber increases, and the float is pushed up and visa versa
what is a spirometer used to measure
- breathing rate
- tidal volume
- vital capacity
- oxygen uptake
how is a trace made using a spirometer
pen, connected to chamber, makes a trace on a kymograph, which rotates slowly
why is soda lime used and what is the effect
absorbs CO2 breathed out so volume of chamber decreases
why is a counter balance used
removes resistance to breathing
why is a nose clip used
prevents escape or entry of air through nose, which would make the results invalid
give safety precautions using a spirometer
- use a nose clip
- sterilise mouthpiece
- use medical grade oxygen
- ensure person is in good health
- ensure equipment is used correctly (give example)
define breathing rate
number of breaths per minute
