Gas Exchange in Mammals
- In mammals, the lungs are gas exchange organs.
- They help to get oxygen into the blood (for respiration) and to get rid of carbon dioxide (made by respiring cells) from the boyd.
Structure of the gaseous exchange system
- As you breathe in, air enters the trachea (windpipe)
- The trachea splits into two bronchi - one bronchus leading to each lung.
- Each bronchus then branches off into smaller tubes called bronchioles.
- The bronchioles end in small 'air sacs' called alveoli.
- This is where gases are exchanged.
- The ribcage, intercostal muscles and diaphragm all work together to move air in and out.
- These form the gas exchange surface.
- Alveoli are arranged in bunches at the end of the bronchioles.
- They are surrounded by a network of capillaries, giving eah alveolus its own blood supply.
- Each alveolus is made from a single layer of thin, flat cells…