| A | B |
|---|
| What is breathing? | Breathing is a mechanical process that occurs in 2 stages, inhalation and exhalation |
| What is inhalation? | Inhalation occurs as air is drawn into the lungs |
| What is exhalation? | Exhalation occurs as air leaves the lungs |
| How does inhalation result? | Inhalation results from a change in air pressure in a chamber called the chest cavity ( thoracic cavity) |
| How does the air move in and out of the lungs? | The air is freee to move in or out through the nose, trachea(windpipe) and bronchial tubes |
| What is the diaphragm? | A thin membrane like muscle which forms the floor of the chest cavity |
| What happens when you inhale? | Contractions of the diaphragm and the intercostals muscles attached to the ribs cause the size of the chest cavity to increase . The diaphragm flattens and the intercostals rise up and out which increases the volume of the chest cavity, This lowers the air pressure and the air rushes in |
| Exhalation is the opposite of what ? | Inhalation |
| What happens during exhalation? | the diaphragm and intercostals rexlax the diaphragm becomes domed shaped and the ribs drop down and in The chest cavity becomes smaller and air pressure becomes higher Air is pushed out or the lungs |
| What part of the brain controls breathing? | Medulla oblongata |
| Is breathing voluntary or Involuntary? | Involuntary action |
| What does the medulla react to? | the amount of carbon dioxide in the blood |
| What happens as carbon dioxide increases ? | The breathing rate increases |
| What happens as carbon dioxide decreases? | The breathing rate decreases. |
