Immunology Flashcards
What is the main function of the immune system?
To resist or eliminate potentially harmful foreign materials (pathogens).
What are the 2 types of immune response?
Innate immunity
Adaptive/acquired immunity
What must happen before an immune response is triggered?
Pathogens must pass the external barriers.
The pathogen must first attach to and penetrate the surface epithelial layers of the body.
List some external barriers
Skin
Mucus - mucosal epithelial cells coat cell surfaces
Saliva
Tears
Urine
Sweat
Describe the innate immunity
Always present and ready
First and immediate response
Less strong than adaptive/acquired immunity
No memory of past cells
Non-specific, always produces the same response.
Can distinguish between human cells and pathogens but cannot distinguish between different types of pathogens.
Describe the adaptive immune response
Production of antibodies
Takes a few days before response is seen.
Has a memory.
Can distinguish between different types of pathogens due to antigens. 
Describe the types of cells involved with innate immunity
Phagocytes, track down engulf and destroy pathogens. 2 types -
Neutrophils
Most abundant WBC
Contain granules filled with destructive enzymes
Macrophages (monocytes)
WBC
Less abundant
Destroy bigger microbes
Process specific parts of pathogens called antigens and present these processed antigens to the cells of the adaptive immune system.
Outline the process of phagocytosis
- The phagocyte moves around the body towards the microbe.
- The microbe attaches to the surface of the phagocyte
- Endocytosis of the microbe and formation of phagosome
- Fusion of phagosome with lysosome
- Killing of microbe through digestion by enzymes
- Waste materials are discharged out of the cell.
What is the basic role of eosinophils?
Helps combat parasitic infections
Granules contain many enzymes which are useful when combating parasitic infections.
Also involved in allergy and asthma
What is the role of mast cells?
Responsible for the allergic reaction.
What happens when mast cell recognises it’s antibody?
Mast cells have immunoglobulin E (IgE) receptors. IgE receptors recognise the IgE antibodies and a complex is formed.
The IgE antibody recognises an allergen and this activates the mast cell.
The mast cell then releases histamine. Histamine targets its own receptors causing an allergic reaction.
What are cytokines?
Small proteins secreted by immune cells. Playing an important role in both innate and acquired immunity.
Involved with cell communication
How do cytokines work?
A cytokine producing cell is induced by stimulus to release cytokines.
Cytokines bind to receptors on target cells producing signalling molecules which lead to many biological effects in the cells.
Complex process
