INTRODUCTION TO THE IMMUNE SYSTEM
A. a comprehensive system of answers
1. The immune system is a set of responses that protects the body from infections, bacteria, viruses, fungi, toxins and parasites (Fig. 8-1).
2. Bacteria, viruses, and other pathogens attack the human body more than 100 million times a day. For this reason, the human body, the immune system tries to control the rapid spread of invasion by microorganisms.
B. Themselves In Comparison To Others. When the immune system detects cells or molecules, it must determine whether these individuals (part of the body) or foreign substances. Molecules can be harmless substances like pollen, or are part of microorganisms. Microorganisms, in turn, may be harmless or pathogenic.
A. The Main Purpose
1. The main goal of the human immune system is to protect human life (host) by identifying foreign substances in the organism (bacteria, viruses, fungi and parasites), and also to create a defense against them [1,2].
2. The body recognizes, bacteria, viruses, fungi and parasites, as something alien to himself and responds by (1) the transfer of certain types of cells in the source of infection, and (2) Production of biochemicals counteraction to the foreign invaders.
B. the way that the individual organism responds to the infection known as the response of the host.
3. Consequences of the loss of function of the immune system. To complete loss of immunity lethal to the body. An example is the human immunodeficiency virus (HIV), the virus that causes acquired immunodeficiency syndrome (AIDS). HIV disables a specific group of immune cells responsible for the coordination of immune reactions. People infected with HIV often develop microorganisms that are rarely cause infection in persons with normal, healthy immune system.
4. The consequences of excess immune response. The immune system can sometimes be confused or so intense in its response that it causes damage to the body that he is trying to protect. Rheumatic heart disease is an example to be confused immune response to infection. The problem starts as infection of the skin or pharynx with streptococcal bacteria. Unfortunately, there are similarities between certain molecules streptococcal bacteria and molecules in human tissues of the heart. As a result of this molecular similarities, immune responses against streptococcal bacteria also attack and damage to the heart tissue infected person.