Immunity And Infection Flashcards
(20 cards)
What is the immune system
The way the body protects itself from injury, harmful agents or infectious organism through an elaborate network called the host defence system
What parts of the body assist with immunity
Bone marrow in long bones, thymus gland where t lymphocytes are developed, lymph nodes: close to blood vessels, spleen and tonsils: red blood cell store, tonsils hold immunity cells
What is cell mediated immunity
How we fight intracellular pathogens, how we keep track of cancer and transplantations, involves B and T lymphocytes, when T lymphocytes are released from the bone marrow they are immature so travel to the thymus so they can leave as mature T cells, then they enter the lymphatic system as CD8 or CD4 cells, CD4 cells activated in the presence of CD8 cells can form killer T cells, effective at phagocytosis and get rid of invading antigens and pre cancerous cells, can be dangerous for transplantations as these T cells don’t recognise the tissue, however there are drugs which can dampen this immune response
What is humoral immunity
Involves b lymphocytes, still released from bone marrow but enter into the lymphatic system immediately, made with antibodies attached to them, which are antigen specific, when B cells recognise the foreign antigens they bind to them and phagocytosis occurs, CD4 cells are required to knock antibodies of the b lymphocytes, both responses have an element of memory, killer cells work quicker if they’ve seen the antigen before
Explain the function of CD8 cells
Release perofin, autolysis (self destruction)
Release lymphotoxin, apoptosis ( cell death)
Explain the function of CD4 cells
Manage and co ordinate immune response, increase production of t and B cells, activate CD8 cells into killer cells, activate blood cells into plasma cells, act as a suppressor, slow immune response
What happens to the B cells in the bone marrow
Mature into plasma cells, activated by t helper cells, plasma cells have antibodies which are antigen specific and produce an element of memory
What’s antibody agglutination
Makes invading organisms stick together
What’s antibody precipitation
Antibody and antigen combine (insoluble)
What’s antibody neutralisation
Antibodies bind to the bacteria or virus so they are incapable of attaching to any other cell
What’s antibody lysis
Direct killing of cell by antigens
What’s antibody opsonisation
Antigen marks the cell, means cells involved in phagocytosis recognise it quickly
What’s activation of complement cascade
Enzymes enhance inflammatory response act as chemotaxis
What’s an infection
An extension of inflammatory and immune processes, complication of immune function
What’s an infectious disease
An state of tissue destruction resulting from invasion of micro organisms
What’s a host
The individual exposed to or contracts infection
What’s resident flora
The natural bacteria that’s on the body but doesn’t cause harm
What can disturb resident flora
Antibiotics as they can kill resident flora
What are the phases of acute infection
Pathogen enters host and passes first line of defence= a inflammatory response, if dealt with effective,g there will be no symptoms, if body can’t deal with it may need antibiotics or nutritional support, if the immune system is inadequate and the infection is overwhelming septicaemia and shock can occur which can be treated with drugs but can be fatal in some cases
Clinical manifestations of infection
Pain, heat, redness, swelling, loss of function, lymphadenopathy, purulent exudate, fever, malaise, weakness, anorexia, headache
