Topic 2C- Cells and the Immune system Flashcards
what can antigens generate
immune response
what are antigens
molecules (usually proteins), found on the surface of cells- including body cells. you get foreign anitgens which the immune system responds to
what do antigens allow the immune system to identify
- pathogens
- abnormal body cells
- toxins
- cells from other organisms but the same species
what are pathogens
examples ?
organisms which cause disease
bacteria, fungi, viruses
why do abnormal body cells cause an immune response
as cancerous or pathogen- infected cells have foreign antigens on the surface
why do pathogens cause disease
they have antigens on the surface which are identified as foreign
what are toxins
are they cells
some toxins are produced…
they are poisons which infect and kill cells
molecules not cells
by bacteria which releases a toxin that can affect nervous system cells
cells from other individuals but same species can cause an immune response because…
cells from other people have differnt antigens to you- these are identified as foreign.
* e.g. an organ transplant with foriegn antigens can lead to rejection of the organ unless drugs are taken to supress the recipients immune system
thats why blood types need to be the same for blood tanfusions
what is a phagocyte
example?
a type of blood cell which carries out phagocytosis
e.g. macrophage
stage 1 of phagoytosis
the phogocyte recognises foreign antigens which are leaving a chemical trail
stage 2 of phagocytosis
the sytoplams of the phagocyte begins to surround the pathogen, and eventually engulfing it
stage 3 of phagocytosis
this creates a phagosome within the cytoplams of the cell
what do lysosomes contain and what are they
lysozymes which is a hydrolytic enzyme
stage 4 of phagocytosis
the lysosmes of the cell fuses to the phagosomes and releases lysozymes which begin to hydrolise the pathogen
