The Immune System

Define Antigen

Structures on the foreign invader that trigger an immune response against them

Define Antibody

Proteins that recognize antigens from a specific foreign invader, and tigger an immune response against

What is Passive Immunity?

Examples- Breastmilk and Antivenom from snake bite

Antibodies transfered into the body from external source, giving immediate protection. No memory cells are formed. Short term. Lasts weeks to months

What is acquired Immunity

Example- vaccines and Actual Exposure

Your own immune system makes antibodies and memory cells when exposed over days or weeks it can last a lifetime

What are the physical barriers

Skin- Blocks the way

First Line of defence

Chemical Barriers

Sweat and oil on skin- acidic, hard for invaders to survive

Stomach Acid- kills pathogens in food

First Line of defence

Physical and chemical barriers

Mucus Lining digestive/ respiratory tract- traps and kills pathogens

First Line of defence

What are the Phagocytes/white blood cells

Neutrophil- First responder/ front line fighter

Monocyte- move to tissue and clean up and signal for help

2nd line of defence

Inflammation

Increases the following at infection site

• Blood Flow

• Temperature

• Swelling

2nd line of defence

Humoral Immunity

Targets invaders that are outside a cell in body fluid

3rd line of defence

B Lymphocytes

recognize antigen of invader and signals for more B lymphocytes to reproduce fast

3rd line of defence

Includes

• Plasma B cells

• Memory B cells

Plasma B cells

Once activated by helper T cells, make antibodies that will attach to antigen of invader. Flagged invaders will be destroyed when more lymphocytes move in. Makes Memory B cells

3rd line of defence

Memory B Cells

Hangs out after battle- mount quicker defences if that same antigen pops up again

3rd line of defence

Cellular Immunity( Aka T cells)

Targets invaders that are inside the cell

T lymphocytes( AKA T cells)

Kills infected cells to develop into-

3rd line defence

Includes

Helper T cells

Cytotoxic T cells

Suppressor T cells

Memory T cells

Helper T cells

Activate Plasma B cells and killer T cells

Cytotoxic T cells( or killer T cells)

Recognize antigen and attack invaders by destroying cell membrane/ releasing enzymes

Suppressor T Cells

Decrease activity of lymphocytes to turn off immune response

Memory T cells

Hangout after battle- mount quicker defence if same antigen pops up again