Keywords

Active immunity

Immunity developed through production of antibodies in response to the antigens of a pathogen.

Agglutinin

Antibodies that cause pathogens to clump together.

Antibiotic

A chemical which prevent the growth of microorganisms.

Antibodies

Globular protein molecules (immunoglobulins) produced by plasma cells in response to stimulation by an antigen.

Antigen

Molecule that stimulates an immune response.

Antitoxin

Antibodies that render toxins harmless.

Antigen presenting cell

A cell that has ingested a pathogen and displays the pathogen’s antigens on its cell surface membrane.

B lymphocyte

Type of leucocyte that is produced and matures in the bone marrow.

Callose

Large polysaccharide deposited in phloem sieve tubes to block them.

Chemotaxis

The movement of cells or organisms towards or away from a particular chemical.

Clonal expansion

The multiplication of selected T and B lymphocytes in the specific immune response.

Clonal selection

The selection of T and B lymphocytes appropriate to an antigen in the specific immune response.

Cytokines

Cell signalling molecules which are used for communication between cells, allowing some cells to regulate the activity of others.

Endemic

A disease that is always present in a population.

Epidemic

The rapid spread of a disease through a high proportion of a population.

Herd immunity

A form of immunity that occurs when a significant portion of a population have been vaccinated and provides a measure of protection for individuals who have not developed immunity.

Histamine

Released by mast cells as part of the inflammatory response. Attracts neutrophils to the site of infection by chemotaxis and increases permeability of capillaries.

Immunoglobulins

Soluble glycoproteins molecules.

Immunological memory

Ability of the immune system to respond very quickly to antigens that it has encountered before due to the presence of memory cells.

Incidence rate

The number of new cases of a disease in a given population in a certain time period.

Inflammatory response

A tissue reaction to injury or an antigen that may include the release of histamine, pain, swelling, itching, redness, heat and loss of function.

Interleukins

A type of cytokine used to communicate between lymphocytes.

Lysozyme

An enzyme produced in tears which digests bacterial walls. keeping the eye free from infection.

Morbidity

The incidence or prevalence of a disease or of all disease in a population.

Mortality

The number of deaths in a population.

Opsonin

Molecule that binds to a pathogen, making it more susceptible to phagocytosis.

Pandemic

An epidemic that has spread worldwide.

Passive immunity

Immunity acquired by the transfer of antibodies.

Pathogen

An organism that causes disease.

Phagocytosis

Phagocytes engulf a pathogen in a vesicle called a phagosome. Lysosome fuse with the phagosome releasing digestive enzymes.

Plasma cells

Differentiated B lymphocytes that produce and secrete antibodies as part of the humoral response.

Ring vaccination

A vaccination of all susceptible individuals in a prescribed area around an outbreak of an infectious disease.

Specific immune response

An integrated immune response to an antigen, especially one mediated by lymphocytes.

T lymphocyte

Type of leucocyte that is produced in the bone marrow and matures in the thymus.

Toxins

A poisonous substance produced within living cells or organisms.

Transmission

Transfer of a pathogen from an infected individual to an uninfected individual.

T regulatory cells

T lymphocytes which suppress the function of other T cells to limit the immune response.

Vaccination

The administration of antigenic material (a vaccine) to stimulate an individual’s immune system to produce antibodies to a pathogen.

Vaccine

A safe form of an antigen, which is taken orally or injected into the bloodstream to provide artificial active immunity against a pathogen bearing the antigen.

Vector

An organism that transfers a pathogen from one host to another.