| Explain process of inspiration | - external intercostal and diaphragm muscles contract
- this causes the ribcage to move upwards and outwards and the diaphragm to flatten, increasing the volume of the thorax
- the lung pressure decreases
- this causes air to flow into the lungs |
| Is inspiration passive or active | - it is an active process, meaning it requires energy |
| Explain process of expiration | - the external intercostal and diaphragm muscles relax
- the ribcage moves downwards and inwards and the diaphragm becomes curved again
- the thorax volume decreases, causing the air pressure to increase
- air is forced out of the lungs |
| Is expiration passive of active | - normal expiration is passive, meaning it doesn't require energy
- however, it can also be forced |
| Define tidal volume | the volume of air in each breath |
| Define vital capacity | the maximum volume of air that can be breathed in or out |
| Define breathing rate | how many breaths are taken per unit of time |
| Define oxygen uptake | the rate at which a person uses up oxygen (dm3min-1) |
| How does a spirometer work | - when a person breathes in and out using a spirometer, the lid of the chamber moves up and down.
- these movements are recored by a pen attached to the lid, creating a spirometer trace |
| What does the soda lime do | it absorbs the carbon dioxide the subject breathed out |
