Inhalation
| rib cage | moves upwards and outwards |
| internal intercostal muscles | relax |
| external intercostal muscles | contract |
| diaphragm | contracts and flattens |
| volume of thoracic cavity | increases |
| air pressure inside lungs | becomes lower than the atmospheric pressure |
| tulang rusuk | bergerak ke atas dan ke depan |
| otot interkostal dalam | mengendur |
| otot interkostal luar | mengecut |
| diafragma | mengecut dan meleper |
| isipadu rongga toraks | bertambah |
| tekanan udara di dalam peparu | menjadi lebih rendah daripada tekanan udara atmosfera |
