Communicable Diseases (4.1) Flashcards
Pathogen
Organisms that cause disease
Active immunity
Resistance in an organism that has developed through the production of specific antibodies in response to a pathogen. It provides long-lasting immunity as memory cells are produced.
Antibiotic
A chemical/compound that kills or prevents the growth of bacteria
Antibiotic-resistant bacteria
Bacteria that mutate to become resistant to an antibiotic, survive and reproduce very rapidly, passing on their antibiotic resistance.
Antibodies
Immunoglobulins produced by B-lymphocytes in response to a specific antigen, triggering an immune response
Antigen
A chemical present on the surface of a cell that induces an immune response
Antigen-presenting cell
A macrophage that displays foreign antigens by isolating the antigen from a pathogen and placing it on the plasma membrane - to activate other immune system cells
Anti-toxins
Chemicals produced by white blood cells that neutralise toxins released by pathogens
Artificial passive immunity
The immunity acquired from the administration of specific antibodies from another organism, e.g: by vaccination
Agglutinins
Antibodies that cause pathogens to stick together - so phagocytes can phagocytoses a lot of pathogens all at once
Autoimmune disease
A condition in which the immune system attacks and destroys healthy body tissue, e.g: arthritis, lupus
B effector cells
A type of B lymphocyte that divides to form plasma cells
Black sigatoka
A fungal disease in tomatoes caused by Mycosphaerella fijiensis, the hyphae of which penetrate and digest host leaf cells, turning them black.
B lymphocytes
Lymphocytes that mature in the bone marrow. There are three main types; plasma cells, B effector cells and B memory cells.
B memory cells
B lymphocytes that provide immunological memory - they remain in the blood for a long time which provides long term immunity
Callose
A large polysaccharide deposit that blocks old phloem sieve tubes - deposited between the cell walls and cell membranes in cells adjacent to infected cells - defence against pathogens
Clonal expansion
Mass production of specific antibody-producing cells (eg mitosis to produce many B cells)
Clonal selection
The identification of a antibody-producing cell with complementary receptors to the shape of the antigen (means B or T cells with complementary receptors to antigen are activated)
Communicable disease
A disease caused by a pathogen which is directly transmitted between organisms
Cytokines
Cell signalling molecules which attract white blood cells to site of damage - used to stimulate immune response
Expulsive reflexes
Coughs or sneezes initiated upon irritation of the respiratory tract. They remove microorganism-containing mucus from the gaseous exchange system
Fungi
Eukaryotic, often multicellular organisms that may cause disease. They digest and destroy cells, and produce spores that can spread rapidly between organisms.
Bacteria
Prokaryotic cells that have cell walls but lack organelles. Some bacteria are pathogenic, producing toxins that damage host cells.
Histamine
A chemical released by mast cells in damaged tissue. During an allergic reaction it constricts muscles in the lungs, making it harder to breathe
Human Immunodeficiency Virus (HIV)
An infectious virus that destroys T helper cells, weakening the immune system of the body. HIV makes an individual more susceptible to infections and can lead to AIDS (Acquired Immunodeficiency Syndrome).
Inflammation
A localised response of vascular tissue to pathogens, damage or irritants
Influenza
Viral infection that destroys ciliated epithelial cells in the gaseous exchange system, exposing the airways to secondary infection.
Interleukins
Signalling molecules used to communicate between different white blood cells - a group of cytokines produced by T helper cells that stimulate B cells
Lymphocytes
White blood cells that contribute to specific immune response (B and T cells)
Lysosome
Membrane-bound organelle that contains digestive enzymes
Malaria
Disease caused by the protoctista Plasmodium that lives within two hosts, (mosquitoes and humans)
Mast cells
Specialised cells in connective tissue that are important in the inflammatory response, releasing histamines and cytokines
Mucous membranes
The membranes lining body cavities that secrete a sticky mucus
Natural active immunity
The production of antibodies by the immune system following infection
Natural passive immunity
The immunity acquired by an infant mammal when antibodies are transferred through the placenta or breastfeeding from the mother
Non-specific defences
Defenses that are always present and are the same for all organisms, e.g: skin, blood clotting, inflammation, mucous membranes and expulsive reflexes
Oposins
Proteins that bind to the antigen on a pathogen and then allow phagocytes to bind
Passive immunity
Immunity achieved when antibodies are passed to the individual through breast feeding or injection
