Cell Recognition And The Immue System Flashcards
What ways do our body’s prevent the entry of pathogens?
Skin Mucous Tears Saliva Inflammation Recognising foreign cells
What molecules are used to recognise foreign cells?
Proteins
What can the surface proteins recognise?
- Pathogenic cells
- toxins
- abnormal body cells- cancer
What are the surface molecules that identify viral particles and toxins known as?
Antigens
Where are antigens found in our body?
- Cell surface membranes
- bacterial cell walls
- surfaces of viruses
What are self antigens?
Antigens produces by the organisms own body cells.
What are non-self antigens?
Antigens that are not produced by the organisms own body.
They stimulate an immune response
What is antigen variability?
The antigens present on their surface change frequently due to genetic mutations.
What are phagocytes?
White blood cells that are produced continuously in the bone marrow.
What do phagocytes do?
They are responsible for removing dead cells and invasive microorganisms.
What are the two main types of phagocytes?
Neutrophils
Macrophages
What do neutrophils do during phagocytosis?
That get attracted to the site of the pathogens.
The antibodies then trigger the neutrophils to attack and attach to the pathogen.
Once attached to a pathogen , the cell surface membrane of a neutrophil extends out and engulfs the pathogen in a phagocytic vacuole. (Phagosome)
This is known as endocytosis.
What do lysosomes do during phagocytosis?
A lysosome will fuse with the membrane of the phagosome and releases enzymes to digest the pathogen.
These enzymes destroy the pathogen.
After killing the pathogen the neutrophils die.
Where are macrophages produced?
Bone marrow
How do macrophages fight pathogens?
They cut pathogens up to display the antigens of the pathogen often on their surface.
These antigens can then be recognised by lymphocytes.
