1. Respiratory System
Revision

2. Respiratory System
The respiratory system is mainly concerned with breathing
The function of the respiratory system is to get oxygen into the body and carbon dioxide out of the body.
The parts of the respiratory system are:
air passages
lungs
diaphragm

3. Respiratory system

4. Respiratory System

5. Passage of Air
Enters the nasal cavity, here the air warms, moistens & is filtered.
Air then passes into the larynx
Air is then passed down the trachea (windpipe)
Air then moves through the bronchi (left & right bronchus)
Air then passes into the bronchioles
Air then goes into the alveoli

6. Gaseous Exchange

7. Gaseous exchange
The O² breathed in goes through the mouth or nose, down the trachea, into the lungs and into the alveoli.
The O² passes through the alveoli walls into the red blood cells, via the capillaries.
The O² joins with haemoglobin to make oxyhaemoglobin.
The oxyhaemoglobin is used by the working body and is transported by the circulatory system to cells needing to release energy.
CO² is produced as a waste product
This is converted into a gas and passes back through the alveoli walls, via the capillaries into the blood plasma.
Blood takes it back to the capillaries in the lungs.
CO² passes through the capillary and alveoli walls into the alveoli.
It is then exhaled from the body.

8. Mechanism of Breathing
Inspiration
Diaphragm pulls down
Intercostal muscles contract
Air pressure is reduced
Air is sucked through the tubes into the lungs
Chest expands
Expiration
Diaphragm relaxes into its dome position
Intercostal muscles relax
Chest becomes smaller
Pressure increases on lungs
Air is forced out

9. Composition of Air Inhaled 79% = Nitrogen 20% = Oxygen Exhaled
Trace = Carbon Dioxide
Exhaled
79% = Nitrogen
16% = Oxygen
4% = Carbon dioxide

10. Definitions Vital Capacity
The maximum amount of air that can be forcibly exhaled, after breathing in as much as possible.
Residual Volume
The amount of air left in the lungs after a maximal breath.
Respiratory Rate
Number of breaths per minute
Tidal Volume
Amount of air breathed in or out at rest
Minute Volume
Volume of air breathed in, in 1 minute.

11. Respiratory System during exercise
Tidal volume increases
Breathing rate increases and becomes deeper and more regular
Heart beat increases, supplying the demand for more O² in the working muscles
Gaseous exchange in alveoli increases

12. Long-term effects of training on the respiratory system
Endurance
Increased training makes gaseous exchange in the alveoli more efficient.
Muscles are able to work at a harder level for longer without tiring – increasing the vital capacity of the lungs.
Interval over short distances at high speeds
New capillaries are formed, heart muscle is strengthened and delivery of O² improves.