1. Respiratory System

2. 6.4 Gas exchange
Distinguish between ventilation, gas exchange and cell respiration.
Explain the need for a ventilation system.
Describe the features of alveoli that adapt them to gas exchange.
Draw and label a diagram of the ventilation system, including trachea, lungs, bronchi, bronchioles and alveoli.
Explain the mechanism of ventilation of the lungs in terms of volume and pressure changes caused by theinternal and external intercostal muscles, the diaphragm and abdominal muscles.

3. What is the equation of respiration?
Cellular respiration is the controlled release of energy in the form of ATP from organic compounds in cells.
C6H12O6+6O26CO2+6H2O+energy(ATP)

4. What is gaseous exchange?
It is the exchange of gases between on organism and its surroundings including the uptake and release of carbondioxide in animals and plants.
It takes place by diffusion

5. Diffusion of gases depend on;
The size of the surface area
The difference in the concentration
The length of the diffusion path

6. Gaseous exchange in animals
Aquatic animals versus land animals
They need a ventilation pumping mechanism, which moves air into and out of the lungs efficiently, thereby maintaining concentration gradient for diffusion.
They need blood supply
Respiratory pigment

7. Gaseous Exchange in Humans

8. [animation]

9. Section 6.16 – The path taken by air to the lungs

10. Larynx

11. Tracheabronchibronchioles

12. alveoli

13. Features of alveoli;
Thin …
Folded
Moist

14. Have an excellent transport system …

16. Pleural Membranes

17. Efficiency of lungs Large surface area … Supply of blood …
Wall of alveoli
Surface film of moisture

18. Lungs volume
Tidal volume: volume of the air normally exchanged in breathing
Residual volume: volume of the air remaning in the lungs after maximum expiration
Vital volume (capacity): the total possible change in lung volume- the maximum volume of air that can be exhaled after a maximum inhalation.

19. BREATHING MECHANISM

21. Inhalation (Inspiration)
Volume of chest cavity increases
Diaphragm (dome shaped muscle at the bottom of the chest cavity) moves downward
Air pressure in lungs decreases (so air is pushed into lungs)
The intercostal muscles contract, ribs and sternum move up & out

22. Exhalation(Expiration)
Volume of chest decreases
Diaphragm moves upward
Air pressure in lungs increases (so air is pushed out lungs)
The intercostal muscles relax, ribs and sternum move down&in