The Immune System

The first line of defense in the organ system is called the integumentary system. It is the most important and largest of all the body system. B-Cells is a type of white blood cells called b-lymphocyte. They are developed by stem cells in the bone marrow. (a flexible tissue found in the inside of the bone.) B-Cells create antibodies to mark the bacteria or viruses. The antibodies are y-shaped proteins and they attach to antigens so the body could identify the bacteria or virus and destroy them. The helper T-Cells is a type of white blood cell witch is also called CD4-positive T lymphocyte. They are very active and they circulate around the body to check for any signs or bacteria or viruses. The helper T-Cells carries CD4 and makes it the first cell to be targeted by HIV. The killer T-Cell is also a type of white blood cell but are capable of provoking death to infected or tumered cells. The killer T-Cell attack cells that have specific surface antigens and cells that are damaged. Even though they are both a type of white blood cell the B-Cells are used to produce antibodies while T-Cells are used to identify antigens and to release a chemical that attracts the macrophages to destroy the antigen. Pathogens is a type of bacteria that causes a disease in humans. This causes sickness. Some examples of pathogens are hostile bacteria and viruses. An antigen trigers the immune system to get a reaction. They are found on the surfface of a bacteria or a virus. One major difference between a virus and becteria is that bacteria is a self reproducibg organism. It knows when to split its DNA and RNA into two. As for a virus, it can not reproduce without a living host.