This page has been dedicated to inform about human diseases. This is also a human biology project of mine for school.
The Nature of Disease- Section Objectives
1. Disease is any change, other than an injury, that interferes with the normal functioning of the body. Some infectious diseases-such as the common cold, measles, influenza, and mumps- are spread from one person to the next through coughing and sneezing. Other infectious diseases are spread through contaminated water supplies or through food that has been handled by people infected with some sort of diseases. Still, there are other infectious diseases that are spread by infected animals such as ticks and mosquitoes. Sexual contact can also spread diseases, often called STD’s (sexually transmitted diseases).
2. The germ theory of infectious disease states that microorganisms cause diseases.
3. Koch’s postulates
A.) The microorganism should always be found in the body of the host organism and not in a healthy organism.
B.) The microorganism must be isolated and grown in a pure culture away from the host.
C.) When the microorganisms grown in a pure culture are injected into a new host organism, they produce disease.
D.) The same microorganisms should be re-isolated from the second host and grown in a pure culture, after which the microorganisms should still be the same as the original microorganisms.
1. Scientists group infectious diseases according to the kind of pathogen that causes them.
2. Diseases caused by viruses are AIDS, poliomyelitis (polio), smallpox, and measles. A bacterium causes gonorrhea. Rocky Mountain spotted fever and typhus are two diseases caused by rickettsiae. Fungal infections can cause athlete’s foot and the scalp infection known as ringworm. A protozoan causes malaria. Amebic dysentery and African sleeping sickness are two other diseases caused by protozoan.
1. Cancer is a life-threatening disease in which cells multiply uncontrollably and destroy healthy tissue.
2. Viruses, radiation, and chemicals are three main causes of cancer. In recent years, scientists have been able to discover that viruses caused a number of cancers. This has led to the proposal of a viral theory of cancer. According to this theory, cancer-causing genes known as oncogenes in certain viruses cause normal cells to turn into cancer cells. Viral oncogenes are similar to normal cell genes that control cell growth, cell division, and metabolic pathways. When oncogenic viruses infect the normal cells,
3. The three methods of treating cancer are surgery, radiation therapy, and drug therapy.