1. Artificial Respiration: 

1. During accidental conditions of any person such as gaseous toxicity or CO effect, electric shock etc, if breathing stops and heartbeats continue then human life can be saved by giving artificial respiration. 

2. Normally, the artificial respiration activates the respiratory centres, hence normal breathing can be restored. 

3. Many methods of artificial respiration are known but “Mouth to Mouth technique” is most effective. 

4. Following are the main steps for artificial respiration: 

• Keep the patient on a hard bed in a straight position. Keep one hand on the head of the patient and another hand below the head, so respiratory passage gets open. 
• Close the nose of the patient with the hand which is on the head of the patient and put a mouth on the patient’s mouth in such a way that airtight position forms. The hand below the head is to be remained as such so that neck remains stretched. 
• Push air into the mouth of the patient forcefully about 12 times of tidal volume (500 ml). 
• Open the nose and mouth of the patient and allow expiration. 

2. Respiratory disorders (diseases) : 

Asthma: 

1. It is a respiratory disease. It is a condition in which a person’s air passage becomes inflamed, narrow, swells and produces more mucus, which makes difficult to breathe. 

2. The disease is caused due to pollens, dust particles, cold or smoking etc. It causes difficulty in breathing, chest pain, coughing and wheezing. The best remedy to prevent asthma is to live away from allergens. 

3. Asthma can be managed with rescue inhalers to treat symptoms i.e. bronchodilators. Antibiotics are required to cure it. 

Bronchitis: 

1. This disease involves inflammation of the timing of bronchial tubes which carry air to and fro from the lungs. 

2. Symptoms include – swelling on the internal lining of bronchitis that causes constant coughing. Bronchitis may be acute or chronic. 

3. It may also be due to chemicals in the smoke of tobacco. Avoiding smoking is the best way to prevent asthma. 

Emphysema: 

1. It is caused due to heavy smoking and air pollution. 

2. Smoking causes continuous stimulation in the lungs which destroys the alveolar walls.

3. This results in increased air space but decreases in the respiratory surface in the lungs.

4. Lung elasticity is also reduced due to the increased amount of connective tissues. It causes difficulty in expiration. 

5. Avoiding smoking, use of antibiotics and bronchial-dilators are helpful to get relief.

3. Respiratory volumes

• Lung volumes are also known as respiratory volumes. 
• It refers to the volume of gas in the lungs at a given time during the respiratory cycle. 
• Lung capacities are derived from a summation of different lung volumes. 
• The average total lung capacity of an adult human male is about 6 litres of air