Cells and immune system Flashcards
stages of immune response
- phagocytosis
- t cells
- b cells
- antibody production
what is a phagocyte + example
type of white blood cell carrying out phagocytosis (engulf pathogens)
1st type of cell to respond to immune system trigger in body
phagocytosis
- phagocyte recognises foreign antigens on pathogen
- phagocyte engulfs pathogen - cytoplasm moves around it
- pathogen now contained in phagocytic vacuole
- lysosome fuses w phagocytic vacuole and lysozymes break down pathogen
- phagocyte presents pathogen antibodies on surface, activating other IS cells (phagocyte acts as antigen presenting cell)
what is a phagocytic vacuole
bubble in cytoplasm of phagocyte
what is a lysosome
organelle containing enzymes called lysozymes
what is a t cell
type of white blood cell
activated by surface receptors binding to complimentary antigens
2 types of t cell and function
- helper t cells - release chemical signals activating phagocytes + cytotoxic t cells + b cells
- cytotoxic t cells - kill abnormal + foreign cells
what are b cells + selection
type of white blood cell, covered w antibodies
each has different shape antibody on its membrane so different ones bind to different antigens
when it does, that and helper t cells activates it = clonal selection
activated cell divides into plasma cells
antigens
proteins that bind to antigens to form antigen-antibody complexes
process of antibody production
- plasma cells are identical to b cells + secrete many monoclonal antibodies which bind to antigens on surface of pathogen to form complexes
- antigen has 2 binding sites - 2 pathogens are clumped together (agglutination)
- phagocytes phagocytose multiple antibodies at once
- all pathogens carrying antigen destroyed
what are monoclonal antibodies
antigen specific antibodies
what does specificity of an antibody depend on
variable region
what is the variable region
form antigen binding site,
