Specific defences Flashcards
What is released upon damage
Cytokines
Name the two types of lymphocytes
B and T
What do lymphocytes respond to
Specific antigens on invading pathogens
What are antigens
Molecules (often proteins) found on the surface of cells. They act as a marker for ‘self’ calls or invading/diseased cells.
What is triggered when lymphocytes bind to antigens
Specific immune response
What is clinal selection theory
Lymphocytes have a single type of membrane receptor which is specific to one antigen. Antigen binding leads to repeated lymphocyte division resulting in the formation of a clinal population of identical lymphocytes.
What do B lymphocytes produce
Antibodies
What are Antibodies
Y-Shaped proteins that have receptor binding sites specific to a particular antigen on a pathogen.
What do antibodies do
Bind to antigens and inactivate the patjogen. The resulting antigen-antibody complex is then destroyed by phagocytosis
What is an allergic reaction
When B lymphocytes respond to antigens on harmless substances and issue a hypersensitive response
How do T-Lymphocytes work
They recognise antigens of the pathogen on the cells membrane and induce apoptosis
What is apoptosis
Programmed cell death
Describe apoptosis
T lymphocytes attach onto infected cells and release proteins. These proteins diffuse into the infected cells and cause production of self-destructive enzymes which cause cell death. The remains are then removed by phagocytosis
AWhat cause autoimmune disease
Failure of the regulation of the immune system leads to T lymphocytes responding to self antigens. In autoimmunity, the T lymphocytes attack the body’s own cells
Give two examples of autoimmune disease
Rheumatoid arthritis and type one diabetes
