Immunity Flashcards
external defence against disease
skin - epidermis
internal defence against disease (3)
blood clotting
stomach acid
epithelial in airway barrier
types of leucocytes
lymphocytes/phagocytes
purpose of lymphocytes
immune response by releasing antibodies
purpose of phagocytes
mark for lymphocytes or engulf
how does the body distinguish between non-self and self
own cells have cell surface antigens that are detected as foreign in someone else’s body but normal in your own
when are antibodies produced
when lymphocytes meet foreign antigen
where are white blood cells made
bone marrow
types of phagocytes
neutrophils/macrophages
purpose of phagocytes
remove dead cells and breakdown of pathogen/bacteria
process of phagocytes (6)
- chemotaxis - histamine released to attract pathogen to site
- binding by complementary shape to antibody
- bacteria marked by antibody
- endocytosis
- lysosome/phagocyte vacuole breakdown
- digestion by proteases + enzymes
where are neutrophils found
blood
how many of leucocytes are neutrophils
60%
describe neutrophils
squeezes through capillaries
short lived and die
released in large numbers
where are macrophages found
organs
describe macrophages (4)
monocytes in blood that mature into macrophages in organs
larger than neutrophils
(lungs/kidney/lymph nodes)
describe lymphocytes
smaller than phagocytes
large nucleus
describe B cells
release antibodies and made in bone marrow where its spread through body
one mature B cells = one antigen
describe activated B cells
plasma cells (short time) memory cells (long time)
how are B/T cells matured (3)
- B cells divide by mitosis to form clones
- antibody receptors produced
- mature B cells circulate in liver
how do B cells work (4)
primary response: one B cell antibody spots antigen
mitosis
plasma cells secrete antibodies
secondary response: memory cells divide to form more plasma cells
describe T cells
differentiate into memory cells
mature in thymus
describe helper T cells
release cytokines to stimulate
B cells - plasma cells/secrete antibodies
phagocytosis
describe killer T cells (2)
- search for cells with pathogen on cell surface membrane
- recognise antigens and attach to surface and secrete hydrogen peroxide (kills cells/pathogens)
where are antibodies found during an immune response
surface of pathogens NOT on memory cells
how do vaccines work (8)
active immunity; vaccine contains pathogen; immune response; B cells secrete antibodies; T helper cells; clonal selection; memory cells remain; faster secondary response;
describe antibodies (4)
- globular + glycoprotein
- specific
- hinge for flexibility
- antigen bind to variable region
describe the structure of antibodies
heavy chain on the bottom and light chain on the top with disulphide bonds between chains
describe artificial active
vaccination
describe artificial passive
direct injection of antibodies
describe natural active
your own body makes antibodies to infection
describe natural passive
breast milk passing antibodies
problems with vaccines (5)
- poor response
- live virus
- antigenic variation
- antigen concealment
- more than one strain
why was small pox able to be eradicted? (5)
- didn’t mutate/change surface antigen
- infected people were easy to identify
- didn’t affect animals
- cheap to produce vaccines
- same vaccine used
describe autoimmune diseases
immune system attacks one or more self antigens
how do autoimmune diseases come along (3)
maturation of T cells in thymus gland
many cells destroyed - they are complementary to self antigens
some don’t and activate immune system to protein destruction
describe myastenia gravis
affects neuromuscular junctions
antibody blocks acetylcholine receptor blocking the motor neurones
symptom of myastenia gravis
muscle weakness
where does multiple sclerosis affect
central nervous system
symptom of multiple sclerosis
progressive paralysis
where does rheumatoid arthritis affect
joint
symptom of rheumatoid arthritis
progressive destruction of joints
where does type 1 diabetes affect
endocrine tissue in pancreas
symptom of type 1 diabetes
destruction of cells that secrete insulin
where does systemic lupus erthromotasus affect
skin, kidneys and joints
symptom of systemic lupus erthromotasus
progress deformity
