Respiration is the process of taking in and using oxygen. There are
three different phases of respiration: external respiration, internal
respiration, and cellular respiration. External respiration is the intake of
oxygen from the environment and the release of carbon dioxide. In internal
respiration, oxygen is carried to the cells and carbon dioxide is carried away
from the cells. In cellular respiration, oxygen is used in chemical reactions
within the cells.
of the respiratory system
are: bronchial asthma, the common
cold, and diphtheria.
Bronchial asthma is a disease in which the bronchial passages are made
smaller and swelling of the mucous lining causes blockage of breathing, usually
due to dust, animal fur or feathers, or pollen. Many people have asthma which
is caused by allergies, called extrinsic asthma, usually suffer from hay fever.
Non allergic asthma, which adults usually have, is called intrinsic asthma.
Intrinsic asthma is usually caused by respiratory infections and emotional
upsets. A typical asthma attack begins with coughing, wheezing, and shortness
of breath. Some people have dry coughing as the only symptom. Attacks usually
last only a couple hours. An attack may happen again in hours to even years
after the first attack.
Asthma attacks can be treated and prevented by the use of drugs. Albuterol
or terbutaline, which can bring relief within minutes, is the usual treatment.
The common cold
is another disease of the respiratory system. The cold
affects the mucous membranes of the nose and throat. It causes nasal
congestion, sore throat, and coughing. A cold usually lasts up to an average
of seven days. There is no known cure for the common cold yet.
Diphtheria is another respiratory disease that, most of the time, affects
children. The disease enters the body through the nose and mouth and attack the
mucous membrane where they multiply and secrete a powerful poison. The heart and
central nervous system are damaged by the poison and it can lead to death.
Toxoids, which are given to infants during the first year of life, are
harmless forms of the diphtheria poison which immunize the children against