Emphysema is a disease of the alveoli. This disease often affects people who already suffer from chronic bronchitis. The walls of many of the alveoli break down or become overstretched. Therefore movement of oxygen into the blood is slower because there are fewer alveoli. People with chronic bronchitis and emphysema of the lungs usually have a cough which carries large amounts of mucus (phlegm) up to the mouth. They find breathing difficult, and they wheeze all the time as they breathe. They move slowly. They find it difficult to climb even a few steps because they quickly become exhausted. People who suffer from bronchitis and emphysema are much more likely to get pneumonia than are healthy people. Pneumonia is very dangerous for people with emphysema. If someone with emphysema gets pneumonia as well, this usually kills them.
Each year about thousands of men and women die from bronchitis and emphysema, many of them having suffered years of disability. The number of people actually suffering from these diseases is far greater. Several million working days are lost each year due entirely to sickness caused by these two diseases.
The proportion of people who die from chronic bronchitis and emphysema has been falling steadily in recent years. There are probably several reasons for this. Various clean air laws have provided smokeless zones in towns and cities. These laws have reduced the amount of coal smoke and other fumes in the air. Conditions in factories are better than they were. There are better ways of protecting workers from dusts and smoke. These include dust extractors and special protective clothing, especially face masks. There have been several improvements in the treatment of patients with bronchitis. They can be made to feel more comfortable and they probably live a little longer. Fewer people now smoke cigarettes. Those who do smoke, may be smoking less. The tar and nicotine content of cigarettes sold have both been reduced steadily in recent years. Tar and nicotine are both harmful.
One of the most common breathing diseases is bronchitis. Bronchitis is a disease of the air passages.
In this disease too much mucus is produced in the air passages, and the walls become inflamed. The ciliated cells are gradually destroyed, and so the only way to move the mucus up to the mouth is by coughing. The extra mucus and the inflamed walls both make the air passages narrower. This obviously makes breathing more difficult.
Common symptoms of bronchitis are wheezing and a tight feeling in the chest, especially in the morning. This causes great discomfort and distress. Chronic bronchitis seems to be caused by breathing air containing dust, smoke of various kinds or other fumes for several years.
The disease is more common in towns than it is in country districts. It is also more common in smokers than in non-smokers. About 95 people out of every 100 with chronic bronchitis are smokers.
Air contains the oxygen which we need. It also holds a lot of other things. Some of these can be dangerous, for example, dust, smoke and harmful bacteria. The amount and type of dust in the air varies a great deal. Some types of dust are more harmful than others. In healthy people the bacteria and larger dust particles all get trapped in the upper air passages. They are therefore prevented from reaching the lungs where they might cause infection, irritation or inflammation. The inner surface of all the air passages (nose, trachea, bronchi etc) is covered by special cells of two main types. These are goblet cells, which produce mucus, and ciliated cells, which have tiny hairs called cilia on them.
Mucus is a thick sticky liquid. The cilia move up and down all the time. Dust particles in the air are trapped by the sticky mucus. The cilia carry the mucus up towards the mouth. Coughing also helps. When the mucus gets to the mouth it is swallowed and eventually passes out of the body.
Good health depends partly on a healthy breathing system. The goblet cells and cilia have a very important part to play in making sure that the breathing system stays healthy.
One way to find out what happens when we breathe is to compare the air which we inhale with the air which we exhale. If there are any differences, these should give us a clue about what happens to the air inside us and why we need it.
- Move your hand gently backwards and forwards in the air in front of you. This shows you what ordinary inhaled air feels like.
- Hold your hand a few centimetres in front of your open mouth. Breathe out against it as if trying to whisper the word ‘hah’. You should be able to feel two differences between ordinary (inhaled) air and exhaled air. One of these differences is even easier to see if you breathe onto a mirror.
- Collect a sample of exhaled air in a gas jar or similar container.
- Use an identical container for a sample of ordinary air.
- Find out how long a candle burns in the jar of ordinary air. Then see how long it burns in exhaled air.
After all the difference is pretty obvious. But why do we breathe? What do we need air for? When we eat plants (or animals that have eaten plants), the energy they contain passes into us. Oxygen is used by the body to help to break down the energy-containing foods. This releases the energy in them. This energy is used for many things including moving around/ keeping the heart beating and the body warm. Without oxygen there is no energy, and these vital processes will stop. The body must get enough oxygen. It must also get rid of carbon dioxide because this is poisonous if too much stays in the body. The next activity follows the route taken by oxygen and carbon dioxide as they pass into or out of the body.