1. THE RESPIRATORY SYSTEM

2. Functions The respiratory system delivers oxygen from
the air we breathe into the blood, and removes
the carbon dioxide.
It brings air from the atmosphere into the lungs
Transfers O2 into the blood
Removes carbon dioxide from the blood
Expels heat and water vapour
Allows the vocal cords to create speech as air is breathed out

3. Anatomy The lungs are the major organ of the respiratory system.
They consist of 3 main parts:
The conducting system
The pleura
The diaphragm

4. The Conducting System THE NASAL CAVITY
To warm and clean the air from outside the body
THE PHARYNX
Where the back of the mouth and the nasal passage meet Food is passed into the oesophagus, whilst air is passed to the…
THE LARYNX
The ‘Adam’s Apple’. Contains vocal cords which allow speech as air passes through.

5. The Conducting System THE TRACHEA
The ‘windpipe’. Constructed by rings of hyaline cartilage and sits behind the sternum. Why??
THE BRONCHI
The trachea divides into 2 bronchi Each bronchus feed one of the lungs.
THE BRONCHIOLES
Each bronchus subdivides into a series of subdividing bronchioles
THE ALVEOLI
Tiny air sacs. Each alveolus is only one cell thick and is heavily surrounded by capillaries. WHY??

6. The Pleura The Diaphragm This membrane covers each lung.
It is attached to the inside of the chest cavity and the top of the diaphragm.
It’s purpose is to prevent friction between the lungs and surrounding body tissue.
The Diaphragm
This involuntary / smooth muscle contracts/relaxes to aid breathing.

8. Pressure inside the lungs

9. GASEOUS EXCHANGE
Gases spread from high-concentration areas to low-concentration areas.
The blood in the capillaries arriving at the alveoli is low in O2 and high in CO2.
Air in the alveoli is high in O2 and low in CO2.
Therefore, O2 diffuses into the blood, & CO2 diffuses into the alveoli, where it breathed out.

10. Gas exchange

11. The mechanism of gaseous exchange
The reverse process occurs in the capillaries that
surround the muscle fibres.
The muscle fibres are low in O2, which has been used to produce energy (ATP), but high in CO2, which is a waste product.
The capillaries however, are high in O2, and low in CO2.
Therefore O2 diffuses into the muscle fibres while CO2 moves into capillaries.

12. Oxygen Uptake by the muscles

13. Breathing
During Inspiration (Breathing In) our muscles between the ribs (Intercostal Muscles) contract pulling the rib cage up and out.
The Diaphragm also contracts and flattens.
The lungs then expand and air is sucked in.

14. Breathing
During Expiration (Breathing Out) the intercostal muscles relax and the rib cage moves down and in.
The diaphragm muscles relax and it moves upwards and becomes more domed shaped.
The lungs recoil, and air goes out as the space inside the lungs is reduced.

16. Control of Breathing
The breathing rate and depth of breathing are controlled by the respiratory centre in the brain.
The exercise, the muscles are releasing more carbon dioxide as waste.
The respiratory centre in the brain detects this and initiates the body to breathe more deeply and more rapidly because more oxygen is needed by the muscles.

17. Measuring our Lung Capacity
Vital Capacity – This is the largest volume of air that can be blown out (expired) after a maximal inspiration. (largest breath)
Residual Volume – is the air that remains in the lungs after a maximum expiration. (breathing out as much as as possible)

18. Measuring our Lung Capacity
Tidal Volume – Is the amount of air normally inspired and expired.
Inspiratory Reserve Volume (IRV) – Is the air able to be inspired after a normal breath in.
Expiratory Reserve Volume (ERV) – is the air able to be expired after a normal breath out

19. Measuring our Lung Capacity
Total Lung Capacity is measured by:
TLC = Vital Capacity (VC) +
Residual Volume (RV)

20. Ventilation
Ventilation is the amount of air breathed in and out in one minute.
It is measured by:
Ventilation = Tidal Volume (TV) x Respiratory Rate (number of breathes per min)

21. Things to Remember
During Exercise the things you have to remember are:
Tidal Volume INCREASES
Ventilation INCREASES
Total Lung Capacity INCREASES