Topic 10 - Immune System Flashcards
Primary defense barriers
Eyes
Nose and mouth
Skin
Stomach acid
Breathing system ( trachea and bronchi )
Blood clotting
Pathogen
Microorganism that causes disease
Foreign cells
Not your own body’s cells and molecules
Antigen
A molecule that triggers an immune response by lymphocytes
Lymphocyte
A type of white blood cell. They become activated in the presence of antigens. Two types: B lymphocytes and T lymphocytes
Phagocyte
A type of while blood cell which carries out a non specific immune response and ingests and breaks down pathogens by phagocytosis
Phagocytosis
Phagocytes engulf particles to form vesicle or a vacuole
Antigen - presentation
When an antigen presenting cell e.g. Phagocyte displays foreign antigens on their own cell surface membrane
Cell mediated immunity
Type of response when T Lymphocytes respond to antigens that are presented on a body cekk
T cells
They mature in the thymus and are associated with cell mediated immunity
Clonal selection
As the receptor on a helper T cell attaches to the antigen this activates the T cell to divide rapidly by mitosis and form a clone of genetically identical cells. These cloned T cells stimulate B cells to divide and form a clone of identical B cells all which produce the antibody that is specific to the foreign antigen.
T helper cells
Contains receptors which respond to a single antigen. Many different type of T cell which respond to different antigens
Cytotoxic T cell
Kill abnormal cells and body cells that are infective by pathogens by producing a protein called perform which makes holies in the cell surface membrane
Hummoral immunity
Involves b lymphocytes and antibodies
Monoclonal antibodies
Antibodies produced by a single clone of cells
B cells
Produces a specific antibody that responds to one specific antigen
Plasma B cells
When the B cells stimulate is activated to divide by mitosis it gives a clone of plasma cells which produces and secretes that specific antibody that exactly fits the antigen of the pathogens surface
Memory b cells
Some b cells develop into memory cells which can respond to future infections by the same pathogen by dividing rapidly and developing into plasma cells that produce antibodies as part of the secondary response
Primary response
Caused by initial response to the antigen which involves the production if antibodies and memory cells
Secondary response
Caused by second exposure to the antigen. Memory cells are responsible for this response. Divide rapidly and develop into plasma cells which secrete many antibodies quickly and more memory cells
Passive immunity
Resistance to disease that is acquired from the introduction of antibodies from another individual p, rather than an individual’s own immune system.
Active immunity
Resistance to disease resulting from the activities of an individual’s own immune system whereby an antigen induces plasma cells,s to produce antibodies
Natural immunity
Type of active immunity resulting from an individual becoming infected which a disease under normal circumstances
Artificial immunity
Type of active immunity from vaccines. Inducing an immune response in an individual without suffering symptoms of the disease
What is a vaccination
It contains a disease antigens into the body by injection or mouth or oder to induce artificial immunity
Herd immunity
Arises when a sufficiently large population has been vaccinated which makes it difficult for a pathogen to spread within that population
Antigen variability
Pathogen may mutate frequently so that it’s antigen change suddenly rather than gradually which means vaccines become ineffective because the new antigens on the pathogen are no longer recognised by the immune system
HIV
humain immunodeficiency virus. Causes the disease AIDS
It has a lipid envelope attachment proteins a capsid and two single strands of rna and enzymes
Reverse transcriptase
Enzyme in HIV which enables the production of DNA from RNA
Retrovirus
A group of viruses which have the ability to make DNA from RNA because they have reverse transcriptase
MRNA
single stranded polynucleotide found in HIV
Elisa test
Enzyme linked immunosorbent assay which uses antibodies to detect the presence and quantity of a protein in sample
Antibody
Substance produced by living organisms that can destroy or inhibit the growth of microorganisms
