In addition, the immune system also has

I. OVERVIEW OF IMMUNE SYSTEM >> << We are constantly exposed to infectious agents, and yet, in most cases,

, , we can counter these infections. This is our immune system >> << that allows you to resist infections. The immune system consists of two main

units or non-specific innate immunity and adaptive

or specific immune system (Fig. 1). Immune System

is our first line of defense against invading organisms while

adaptive immune system acts as a second line of defense, and provides

Protection of reinfection by the same agent. Each of the major divisions

immune system has both cellular and humoral

components with which they perform their protective function (Fig. 1). In addition, the immune system also has anatomical features that

function as barriers to infection. Although these two arms of the immune system >> << have different functions, is the interaction between these systems

(ie the components of the immune system influence the adaptive immune system

, and vice versa). Despite the innate and adaptive immune systems function as protection against invasion

organisms, they differ in several ways.

Adaptive immune system takes a while to respond to the invading organism >> << and the innate immune system includes protection that

mostly constitutively present and ready to be mobilized to

infection. Second, the adaptive immune system and specific antigens

reacts only with the body, prompting a response. Unlike

innate system is antigen specific and reacts equally well into various

organisms. Finally, the adaptive immune system demonstrates immunological memory

. He "remembers" that he was faced with invasion of the body

and reacts quickly to the next steps of the same body >>. << Unlike the innate immune system does not show

immunological memory. All immune cells originate in the bone marrow and

they include myeloid (neutrophils, basophils, eosinpophils, macrophages

and dendritic cells) and lymphoid (B-lymphocytes, T lymphocytes and natural

killer) cells (Fig. 2), which are differentiated by the way different >> << (Fig. 3). Myeloid precursors (stem) cells in the bone marrow >> << leads to red blood cells, platelets, neutrophils, monocytes / macrophages

and dendritic cells, whereas lymphoid precursors (stem) cells give

Top NK, T cells and B cells. For the development of T-cell >> << T progenitor cells must go to the thymus where they undergo differentiation

on two different types of T cells, CD4 + T-helper cells

and CD8 + pre-cytotoxic T-cells. Two types of T-helper cells is

held in thymus TH1 cells, which help to CD8 + cytotoxic pre

differentiate into cytotoxic T cells and Th2 cells, which help

B-cells differentiate into plasma cells that secrete antibodies. The main function of the immune system alone / non-self discrimination. This ability to distinguish between a self-propelled and need

protect the body from invading pathogens and to remove or change

modified cells (eg malignant cells). Because pathogens can replicate >> << intracellular (viruses and some bacteria and parasites) or

extracellularly (most bacteria, fungi and parasites), various >> << component of the immune system evolved to protect against qi

different types of pathogens. It is important to remember that infection with >> << body does not necessarily mean the disease because the immune system

in most cases be able to eliminate the infection

disease occurs. The disease occurs only when the breast infection is high, when

virulence of invading organism or a big immunity when

threat. Although the immune system is mostly a >> << a positive effect can be deleterious effects as well. During inflammation >> << that responds to the invasion of the body may be lasix drug reactions

local discomfort and side damage healthy tissue as a result >> << toxic products produced by the immune response . In addition, in some cases >> << immune response may be sent to a tissue

resulting autoimmune disease. .