Immunity Flashcards
(37 cards)
what are the types of immunity?
active and passive
what is active immunity?
Protection by adaptive immune response Individual’s immune system is activated against an antigen Time to develop Immunological memory Immunity develops over weeks
what is passive immunity?
Transfer of antibodies
Immediate immunity
Does not last as no memory
Antibodies degrade overtime
what is natural passive immunity?
Mother to foetus through placenta or milk
Weeks of months of protection which own immune system develops
what is artificial passive immunity?
Receiving antibodies in antiserum from another organism
Antiserum contains specific antibodies
Serum is the fluid of blood
Useful if death will occur before the immune system kicks in
Can suppress active immunity when it is harmful
Snake bite
what is natural active immunity?
Immunological memory from an infection
what is artificial active immunity? types?
Administration of antigens to induce the active immune response
Vaccination
Vaccine is altered or weakened or killed or inactivated
Boosters needed to activate a stronger secondary response
- live attenuated vaccines
- inactivated vaccines
- subunit vaccines
what are live attenuated vaccines? advantages, disadvantages
Weakened living microbe through repeated culturing
Advantage: long lasting as a strong immune response was induced, producing many antibodies
Disadvantage: not safe for people with weak immune systems, cross placenta in pregnant woman and infect baby
what are inactivated vaccines? advantages, diadvantages
Aka killed vaccines
Inactivated by heat, chemicals, radiation
advantages: result in production of many different antibodies, safe for all
disadvantages: stimulate a weak response so require a booster
what are subunit vaccines? advantages, disadvantages
Contain parts of microbes
Advantages: safe, stable, easier to store
disadvantages: need boosters to be more powerful
what is herd immunity?
For immunisation to be effective, a sufficient number of people need to be vaccinated
Essential for those who cannot be vaccinated
what is the allergic reaction? how dangerous? what happens? what antibody is involved?
Allergic reaction
Rapid overreaction to antigens that are harmless (allergens)
Pollen
Mild to life-threatening
Pollen allergy or hay fever is a reaction to antigens on pollen
Release of histamine from mast cells
Antibody immunoglobulin E (IgE) is produced by plasma cells
IgE binds to mast cells and when allergen binds across two antibodies (bridging the gap) mast cell releases histamine
what does the release of histamine cause?
Blood vessel dilation
Increase of blood vessel permeability
Contraction of muscles in air ways
Fluid-secreting cells- teary eyes, runny nose which expel antigens
what are autoimmune diseases?
Adaptive immune system response directed against self-antigens
T cells attack tissues directly
B cells work indirectly, relating antibodies
what are the types of autoimmune disease?
Organ-specific are located in a localised area
Generalised autoimmune diseases are located throughout the body
autoimmune haemolytic anemia
Type II hypersensitivity because antibodies are directed against self-antigens on red-blood cells
rheumatoid arthritis
Type III because involved deposition of antigen-antibody immune complexes in tissue which results in inflammation and damage
Also thought to be type IV as T cells attack antigens in joints
type 1 diabetes
T cells attack and destroy beta cells in the pancreas
Beta cells make insulin which regulates glucose levels
Must inject insulin to maintain glucose balance
Mediated by T cells so Type IV
multiple sclerosis
Myelin sheath is affected
Condition of signals is impaired
Helper and cytotoxic T cells are involved as well as plasma cells producing antibodies and target proteins and lipids in myelin sheath
Oligodendrocytes (produce myelin sheath) are damaged and undergo apoptosis as a result
Macrophages also destroy oligodendrocytes
Type IV
Damage eventually occurs to axons
Suppressors of inflammation and immuneosupressants are used
what is immunodeficiency? what are types?
Immune system cannot adequately respond to antigens or fails to react at all
types: primary and secondary
Primary is when you are born with it
Secondary is squired, can be temporary or permanent eg. AIDS which becomes HIV
what Is HIV? what does it do? what results?
HIV is a retrovirus where virus DNA is inserted into cell DNA so that it produced viruses
Immune system responds but some copies of the virus survive
HIV has a high mutation rate which helps it stay ahead of the immune system
Impairs the immune system by infecting T helper cells
AIDS develops when the immune system is impaired
AIDS puts people are risk of other disease which cause death
how is HIV transmitted?
Present in body fluids of infected people
Transmitted through unprotected sex, sharing needles, to a foetus through placenta
HIV treatment
Antiretroviral therapy (combination of medications to stop AIDs developing):
Blocking binding of HIV to cells
Blocking the transcription of DNA by virus
Blocking the enzymes that integrate the DNA
what is cancer? how can it be caused?
Abnormal cell that multiples
Growth is caused by changed to genes that control growth and a resistance to apoptosis
Carcinogens damage cell DNA
Can be caused by viruses
