Immunology

Question 1

What happens in the immune system?

Answer 1

• Mobile circulating system, cells are produced in the bone marrow during haematopoisesis.
• In thymus lymphocytes mature and receive immunological memory and migrate to the lymph nodes - they filter lymph and act as an antigen presenting site.
• Spleen is also an antigen presenting site that filters bloods and removes old cells, tissue debris, pathogens and immune complexes. It also stores RBC and immature monocytes.
• Liver site for antigen presentation, contains phagocytes and lymphocytres, filters venous blood and synthesises acute phase proteins in response to infection.

Question 2

What is innate immunity?

Answer 2

• Fast within 4 hours with no specific or no memory.

- Phagocytosis occurs and also NK cells, neutrophils and phagocytes.

Question 3

What is adaptive immunity?

Answer 3

• Specific, altered reactivity to specific antigen
• Memory
• cell mediated

Question 4

What the pro inflammatory cytokines?

Answer 4

• IL1: Fever and activates lymphocytes
• IL6: fever, stimulates liymphocytes, acute phase protein production and antibodies.
• IL 8: neutrolhpil chemotaxis
• IL12: Activates NK, helper T cells and Th1
• TNF alpha: increase vascular permeability
• IL4,5,13 - IgE immune response
• Interferon gamma: cell mediated immunity in viral infections
• ILA 10: anti inflammatory response

Question 5

What is the complement system?

Answer 5

• Part of innate immunity, about enhancing the ability of antibodies and phagocytes to clear microbes and damaged cells by promoting inflammation and attacking the pathogen’s cell membrane - classical, alternative and lectin.

Question 6

What are hypersensitivity reactions?

Answer 6

• Type 1: immediate
• Type 2: cytotoxic
• Type 3: Immune complex
• Type 4: delayed