Immune System
Cells involved in the immune system and their functions
Antigens and Antibodies
Passive vs. Active immunity
Purpose and examples of First, Second and Third line of defense
Artificial vs. Naturally acquired immunity
Second Line of Defense:
- Chemical barriers
- Natural killer cells response
- Inflamation
- phagocytosis
- Fever
Third Line of Defense:
- Cellular immune response
- Humoral immune response
First Line of Defense:
- Mechanical barriers (skin and mucous membranes)
Active: Obtained through antigen exposure; Immune response occurs in the person in which antibodies and memoru B-Cells are produced; This is long lasting immunity.
Passive: Obtained by reciving antibodies; Since there is no antigen contact and no immune response occurs, no memory B-Cells are produced; This is short term immunity.
Antigens
Antibodies
Any large particle that can trigger an immune response.
B-cells that are activiated by T-Cells that target and react to antigens. There are 5 major types of antibodies: IgG, IgA, IgM, IgE, IgD.
They have 3 methods of reacting to antigens:
- Direct attack by agglutination
- Activation of complement results in oposonization, chemataxis, and inflamation
- Inflamation
Naturally Acquired: Aquired by natural events such as getting a disease; occurs after exposure to the antigen; long-term resistance results, due to the events of a primary immune response (memory B cells are produced)
Artificially Acquired: Aquired by injection of a vaccine without the person becoming ill from the disease; ince vaccines contain weakened or dead pathogens, person develops long-term immunity, due to an immune response that includes memory B cell formation
Ex: Fever helps produce white blood cells rapidly
Ex: skin is a barrier
- T cells: Help fight off disease
- B cells: Produce antibodies to help fight pathogens
Humoral response and cellular response
Humoral response produces antibodies made by B cells, and cellular response is when cytotoxic T cells destroy infected cells