Cells - Immunity: Key Terms Flashcards
Pathogen
Any microorganism that causes disease
Immunity
The means by which the body protects itself from infection
Phagocyte
White blood cells that engulf microorganisms
Phagosome
The vessel that forms when the phagocyte engulfs a pathogen
Lysozymes
Hydrolytic enzymes that destroy ingested bacteria by hydrolysis of their cell wall
Antigen
Any part of an organism that is recognised as foreign and stimulates an immune response
B-lymphocytes
White blood cells that are associated with humoral immunity
T-lymphocytes
White blood cells that are associated with cell-mediated immunity
Antigen-presenting cells
Cells that display foreign antigens on their surface
Cell-mediated immunity
When T-lymphocytes respond to antigens that are presented on a body cell
Cytotoxic T-cells
Cells that produce perforin to create holes in the cell-surface membrane of abnormal cells and body cells that are infected by pathogens in order to kill them
Humoral immunity
Immunity that involves antibodies
Clonal selection
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Plasma cells
Cells that secrete specific antibodies that lead to the destruction of a specific pathogen
Memory cells
Cloned B-cells that circulate within the blood, ready for any future infection from the same pathogen
Antibodies
Proteins with specific binding sites synthesised by B-cells
Antigen-antibody complex
The formation of an antibody with a specific binding site fitting precisely onto a specific antigen
Variable region
The binding site of an antibody which is different for different antibodies
Constant region
The parts of the antibody that is the same for all antibodies
Monoclonal antibodies
A single type of antibody which is isolated and cloned outside of the body
Antibiotic
A substance produced by living organisms that can destroy or inhibit the growth of bacteria
Antibiotic resistance
The development in microorganisms of mechanisms that prevent antibiotics from killing them
Herd immunity
When a sufficiently large proportion of the population has been vaccinated to make it difficult for the pathogen to spread within that population
Antigenic variability
When a pathogen mutates frequently so vaccines suddenly become ineffective
Vaccination
The introduction of a vaccine containing appropriate disease antigens into the body
Retroviruses
The group of viruses that HIV belongs to
ELISA test
A test used to detect HIV and other diseases, allergens and drugs