Definitions of as level biology gas exchange key words
| Front | Cartilage |
| Back | Connective tissue, keeps airways open and air resistance low; prevents collapse of trachea and bronchi |
| Front | Describe inspiration |
| Back | External intercostal muscles contract and internal intercostal muscles relax Ribs raise outwards and upwards Volume in thorax increase, pressure in thorax decrease Diaphragm contracts and moves down |
| Front | Lungs |
| Back | Organs in the chest cavity surrounded by the pleural membranes which encloses an airtight space |