Human body is a marvel of creation. Our body with all its qualities makes an exciting specimen for research. One of the secret weapons of our body which protects us from harmful viruses, threats, and injuries is the immune system. Whether it is a common cold, or high fever, our immune system plays a crucial role in recuperating from all kinds of illnesses. One of the strong indications of a healthy body is its strong immune system.
Made of a strand of genetic material, viruses are so simple that they aren’t even considered living things. Yet they can trigger illnesses, from the common cold to life-threatening SARS or West Nile virus, by overtaking the genetic machinery of cells within the body. Once in command, they direct those cells to produce more viruses, which, if not stopped, can overwhelm vital organs.
The best strategy is to prevent exposure to the virus in the first place. The immune system protects the body from attack by microorganisms, abnormal cells, and chemicals. Its army includes macrophages, T cells, and B cells. Most often, the external threats are infections caused by invading bacteria, viruses, and fungi, while abnormal or cancerous cells pose the major internal threats. In addition, this complex system oversees the repair of tissues that are injured by wounds or disease.
The most remarkable characteristic of the immune system is its “memory” for foreign substances and organisms.
Once in a while the immune system mistakes a harmless foreign substance for an enemy, resulting in an allergic reaction, such as hive; fever, or asthma. Less commonly the immune system—mistaking an internal signal—attacks normal body tissue, leading to an autoimmune disease such as type 1 diabetes, rheumatoid arthritis, or lupus.
The most remarkable characteristic of the immune system is its “memory” for foreign substances and organisms. Confronted with a virus or other invading organism, the system creates an antibody that will recognize it and mount an attack against it at any future encounter. This mechanism, called acquired immunity, is what makes vaccinations work.
How sick you become depends largely on how strong a defense your immune system can launch.
If the immune system is such a wonder, why do we get sick? The simplest explanation is that often there is a lapse between the time an invading organism enters the body and the time the immune system conquer it. In the interim the invader can make its mark, killing cells.
How sick you become depends largely on how strong a defense your immune system can launch. Infection, cancer, and other illnesses develop when the immune system is weakened by any number of stressors, including viruses and other invading organisms, malnutrition, and the consequences of aging.
Fortunately, antibiotics and sulfa drugs can wipe out most bacterial infections in otherwise healthy people; progress is also being made in the development of antiviral drugs. At times doctors purposely lower immunity to treat an autoimmune disease or to prevent rejection of donor organs.