1. Ventilation
By Olivia and Neha

2. Gas Exchange
The process by which one organism absorbs one gas from the environment and releases another
Occurs by diffusion
Dependant on surface area to volume ratio

4. Cell Respiration Every living cell must carry out Cell respiration.
This is to convert energy into a form that can be used in the cell.
The energy is called ATP.
The ATP is split into ADP and Phosphate, the energy is then released.

5. Ventilation System
Air enters the ventilation system through the mouth or nose then passes down the trachea.
It has rings of cartilage in its wall, to keep it open.
Trachea divides, and forms 2 bronchi.
1 bronchi leads to each lung.
Inside the lung the bronchi is divided into a tree like structure.

6. Ventilation System cont.
The narrower airways is called bronchioles.
They have smooth muscle fibres in their walls, this allows the width of the airways to be different.
In the end of the narrowest bronchioles are groups of alveoil.

8. Types of Ventilation
Quiet inspiration: flattens the diaphragm. Thereby reducing lung pressure. Air flows in until lungs return to 1atm
Vigorous Inspiration: Also with that the ribs move up and out increasing volume more
Quiet Expiration: The diaphragm stops expanding and the elastic fibres recoil. No muscle contraction is involved
Vigorous Expiration: Intercoastal muscles pull the ribs back to normal position. Everything is returned to as it was before.

9. Alveoli and Gas Exchange
Air sacs in the lungs
Type I
Flattened
Cytoplasm 0.15µm
Type II
5% of surface area
Secrete surfactant which coats alveoli to help the oxygen to dissolve

10. Alveoli and cell respiration cont.
Capillary walls are endothelium
Protein Gel
This is gas exchange surface