C3.2 Defence against disease

Lymph nodes

• Small, bean-shaped structures that produce and store cells that fight infection and disease.

• Large, round organs that filter blood and produce hormones.

• Flat, disc-shaped cells that transport oxygen in the bloodstream.

• Long, tubular structures that carry nutrients and waste throughout the body.

Primary defence

• The body's immune response to infections.

• The first line of defense against pathogens, including physical and chemical barriers.

• The process of healing after an injury.

• The role of white blood cells in fighting disease.

Macrophages

• Large phagocytic cells found in stationary form in the tissues or as a mobile white blood cell.

• Small cells that primarily function in the production of antibodies.

• Cells that are responsible for the transport of oxygen in the blood.

• Immune cells that primarily attack viral infections.

Antigen

• A substance that enhances the immune response

• A toxin or other foreign substance that induces an immune response in the body.

• A type of white blood cell

• A vaccine that prevents infections

Opportunistic infections

• Infections caused by pathogens that take advantage of an opportunity not normally available, such as a host with a weakened immune system.

• Infections that are always present in healthy individuals and do not cause disease.

• Infections that are caused by vaccines and lead to immunity.

• Infections that occur only in tropical regions and are related to climate.

Autoimmune disease

• A disease in which the body's immune system attacks healthy cells.

• A condition caused by a deficiency of vitamins.

• An illness that primarily affects the respiratory system.

• A type of cancer that affects the blood cells.

T-lymphocytes

• Produce antibodies

• Activate immune cells and destroy infected cells

• Are part of the innate immune response

• Do not recognize antigens

Retrovirus

• A type of virus that uses DNA as its genetic material.

• A type of virus that uses RNA as its genetic material and reverse transcribes its RNA into DNA.

• A type of virus that only infects bacteria.

• A type of virus that can only replicate in the presence of a host cell.

Attenuated

• Weakened in force or effect, often used to describe a virus that has been weakened for use in a vaccine.

• Strengthened to enhance its effect, often used in treatments.

• Completely inactive and unable to cause any effect, often used in safety protocols.

• Enhanced to increase its potency, often used in research.

White blood cells

• Cells that transport oxygen in the blood.

• Cells of the immune system involved in protecting the body against infectious disease and foreign invaders.

• Cells that help in blood clotting.

• Cells that store fat in the body.