Immune System

3 line of defense?

-Physical/ Chemical

-Innate(non-specific)
-Adaptive(specific), against specific pathogen

Physical/ Chemical?

- Lysosome: kills bacteria before enters the body (saliva)
-Stomach Acid
-Skin

Innate(non-specific)?

-2 main types of phagocytes: neutrophils, macrophages
-Pathogen gets enveloped by a phagocyte; the lysosome fuses with the pathogen and digest the pathogen
-all material had antigen as chemical markers

What happens at injury site?

-Phagocytes get activated

-Release histamine and increase blood flow and immune cells

Adaptive immunity (specific)?

-2 lymphocyte: T cells, B cells

-B cells: mature in bone marrow(plasma cells, B memory cells)
-T cells: mature in thymus( T helper cells, cytotoxic killer T cells)

Humoral immunity?

infection that hasn’t entered the cell yet, only in the interstitial fluid

Cellular immunity?

infections that are in the cell already

Antigen?

chemical markers outside the cell for immune system to check

Antibodies?

-Proteins that bind to antigens, only produced by B cells

-FAB region: variable part, antigen-binding
-Fc region: constant part, bound to B cell

Plasma B cells/ B memory cells?

mass production of antibodies/ stores antibodies for future infections

Killer T cells(Cytotoxic T cells)/ Helper T cells?

directly destroys abnormal cells/Signals B cells and other immune cells to the infected area

Primary Response?

B cells generate antibodies for antigens that haven’t shown up yet

How does antibody work?

-Agglutinate: antibodies and pathogens clump together
-Neutralize: the active site for infections are blocked on pathogens
-Opsonization: make pathogen presentable to macrophage

During the vaccine or infected?

The B cells produce antibodies as they recognize antigens, B memory cells store antibodies for a second exposure to mass produce antibodies

Cell-mediated response?

The pathogen gets into the cell, the cell uses the antigen on the pathogen and place them on the cell membrane for Killer-T cells to recognize it

MHC (major histocompatibility complex)?

-How cells recognize foreign and own cells

-Organ transplant: important to find organs that has similar antigens

-Autoimmune disease: recognizes own cells as foreign cells and destroy it