RespiratORY SYSTEM
AND RESPIRATORY DISORDERS



Respiration or breathing is the process whereby oxygen passes from the air into the blood while carbon dioxide, a waste product, is expelled.

2. This exchange of gases takes place in the lungs.

3. The Respiratory System
§ The respiratory system starts from the nose and mouth, and continues as the throat (pharynx), voice box (larynx) and trachea.
§ The epiglottis at top of the pharynx serves as a protective mechanism that prevents food or fluid entering the trachea (windpipe).
§ In chest, the trachea divides into two branches, the bronchi. Each bronchus enters a l;ung and divides into a number of small branches (bronchioles), and after repeated division it ends as numerous minute air-sacs (alveoli).
§ A fine network of blood vessels surrounds the alveoli, through which exchange of gases takes place.
§ The outer surface of the lungs is covered with a double membrane (pleura).

4. The Respiratory Process
§ The respiratory centre in the brain controls the respiratory process.
§ The mechanism of respiration is controlled by the action of the diaphragm and muscles between the ribs.
§ Air enters the body through nose and mouth, passes down throat (pharynx), through voice box (larynx) into the lungs.
§ The process whereby air is drawn into the lungs is called inspiration (breathing in).
§ Oxygen diffuses through the walls of the alveoli into the blood vessels on its surface and is distributed to all the cells of the body.
§ Carbon dioxide diffuses from the blood into the alveoli.
§ The air it is then expelled from the lungs (expiration).
§ There is a short pause between expiration and inspiration.

5. The air we breathe contains 21% oxygen, and there is still 16% oxygen left in the air we breathe out; this accounts for the effectiveness of mouth-to-mouth ventilation.

6. The average adult at rest breathes 12-18 times per minute.

7. The breathing rate and depth may vary considerably and increase if more oxygen is required (e.g. as in exercise, fever).

8. Management of Casualty with Obstructed Breathing
a. Remove any obvious obstruction:
Over the head and face – such as a plastic bag or pillows.
Around the neck – any constriction.
b. Ensure open the airway
Head tilt chin lift or jaw thrust.
c. Clear the airway
In the open airway position, any foreign matter, such as vomit, loose teeth, dentures or food that can be seen or felt should be removed, if possible.
Hook your first two fingers and sweep around inside the mouth.
Do not spend time searching for hidden obstructions.