1. The gaseous exchange system
Lower sixth

2. Aims
To understand the structure and function of the gaseous exchange system

3. Gross structure of the system

4. Trachea
The trachea lead from the throat to the lungs At the base of the trachea lie the bronchi
Cartilage is present in the trachea in the form of C shaped rings This helps to stop the airways collapsing or bursting as pressure changes
Trachea on the left
Oesophagus on the right

5. Bronchi
The bronchi are at the bottom of the trachea They then branch further into bronchioles
Bronchi contain irregular blocks of cartilage
The cartridge keeps the bronchi open

6. Bronchioles Bronchioles These are smaller branches
They do not contain Cartilage
They are made of smooth muscle (which contracts if you have asthma)
This can contract or relax and thus control the diameter of the airways….
Not having cartilage present allows this to happen

7. Alveoli Alveoli are present at the end of the bronchioles
Thin epithelial tissue. 1 cell thick
Elastic fibers allow stretching
Well vascularised

8. Protection-the goblet cell
Goblet cells are present in the trachea and bronchi Pseudostratified Epithelium Produces mucin-glycoprotien-sticky traps particles

9. Protection- Cilia
Cilia are present They beat and carry the mucus upwards 1cm/min… Speedy Slime! Enters stomach and destroyed

10. Protection-Macrophages
Macrophages are present They are phagocytes They mop up bacteria and dust When you have an infection other phagocytes will join them

11. Summary
We have now reviewed Gross structure of the gas exchange system Fine structure of the gas exchange system How the structure of the gas exchange system relates to it’s function.