immune Flashcards
what is an antigen?
-antigens are cell surface molecules that stimulate an immune response.the immune system recognises as ‘self’ or ‘non-self’ whichs enables identification of cells from other organisims.
Give two differences between specific and non specific immune response?
- Nonspecific: inflammation and phagocytosis, same for all pathogens
- Specific: B and T lymphocytes, complementary pathogen
2 types of specific immune responses
- cell mediated
- humoral
Explain the role of antigen presenting cells?
- Macrophages display antigens from pathogens on its cell surface.(after hydrolysis in phagocytosis)
- Enhances recognition by T helper cells which cannot directly interface (connect) with pathogens.
how do antibodies lead to the destruction of a pathogen?
-formation of antigen antibody complex results in agglutination which enhances phagocytosis
what are monoclonal antibodies?
monoclonal antibodies are antibodies produced from a single clone of B cells
what is an antibody
antibodies are proteins secreted by plasma cells, they are protein molecules that can identify and neutralise antigens.
what are memory cells?
memory cells are specialised T helper cells and B cells which are produced by the primary immune response. and can also divide rapidly by mitosis if encounters the same pathogens.
what are some natural barriers that reduce the risk of infection
- skin
- mucous membrane
- tear ducts
- stomach acid
how does inflammation work in a non specific immune response?
histamine is released by damaged white tissue which causes vasodilation which increases the flow of blood to the infected area and increases permeablity of blood vessel. as a result antibodies, white blood cells and plasma leak out into the infected tissue and destroy the pathogen.
how do ciliated mucous membranes that trap microbes in inhaled air?
Hairlike structures called cilia line the mucous membrane and move the particles trapped in the mucus out of the nose. Inhaled air is moistened, warmed, and cleansed by the tissue that lines the nasal cavity
Where are lysozymes found?
• lysozyme in tears, saliva and stomach acid that kills bacteria.
How is HIV transmitted?
HIV can be transmitted by bodily fluids such as semen or vaginal secretion
How can HIV affect body systems?
It weakens the immune system by damaging cells called CD4 T cells
How is HPV transmitted?
HPV is transmitted by vaginal anal or oral sex