The Human Defence System - created from Mind Map

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Pathogen

The general defence system

The specific defence system

Lines of defence of the general defence system

Monocytes and lymphocytes

Immunity

Specialised cells

An organism that causes disease.

Acts against all pathogens

Is not specific to one pathogen.

Acts against only one particular type of pathogen.

Is called the immune system.

Acts by forming antibodies and by killing infected cells.

Organs of the immune system include the spleen, thymus and lymph nodes.

Skin

Blood clotting

Lysozyme

Chemicals in sebum

Cilia

Stomach acid

Provides a structural barrier to infection.

Prevents the entry of pathogens.

An enzyme found in sweat, tears and saliva. Attacks and dissolves the cell walls of many bacteria.

Contains chemicals that kill bacteria.

Move pathogens down into the stomach to be destroyed.

Hydrochloric acid kills bacteria due to its high pH.

Are white blood cells.

Found in the lymphatic tissue.

React to antigens.

Monocytes

Lymphocytes

Develop into macrophages.

Destroy pathogens and display antigens on their membranes.

An antigen is a foreign molecule that stimulates the production of antibodies.

Attack body cells displaying antigens.

Produce antibodies.

Some survive for many years as memory cells, allowing long-term immunity.

A protein produced in response to an antigen.

Each type of antibody is highly specific to a single antigen.

They inactivate antigens and allow the pathogen to be destroyed.

Induced immunity.

Active immunity.

Passive Immunity

The ability to resist a disease, caused by specific antigens.

A person can make their own antibodies.

Provides long-term immunity.

When pathogens naturally enter the body.

When antigens are artificially placed in the body by vaccination.

Occurs when antibodies are introduced into the body.

Provides short-term immunity.

A child getting antibodies from the placenta or mother's milk.

Getting an injection of foreign antibodies.

B Cells

T Cells

B lymphocytes

Recognise an antigen.

Produce antibodies.

Mature in the bone marrow.

T Lymphocytes

Helper T Cells

Killer T Cells

Suppressor T Cells

Memory T cells

Mature in the thymus gland.

Stimulate B Cells to produce antibodies and killer T cells.

Cytotoxic cells that produce perforin, which causes abnormal body cells to burst.

Turn off immune responses.

Survive for a long time to trigger immunity to the same antigen in later years.