Immunology Flashcards
What are the 2 types of response involved in the immune response?
Innate and adaptive
What is the innate immune response?
Non-specific first line of defence that involves phagocytic cells
What cells are involved in the innate immune response?
Phagocytes, neutrophils and NK cells
What is involved in the innate immune response?
Physical barriers, phagocytic cells and soluble factors
What are the physical barriers involved in the innate immune response?
Tight junctions between epithelia and mucous membranes
What are phagocytic cells?
Phagocytes and neutrophils
What are NK cells?
Cytotoxic cells that attack virus infected cells and cancer cells by forming pores on the target cell membrane and inserting self-destructive enzyme which causes the cell to induce apoptosis
What is phagocytosis?
A type of intracellular killing that is triggered when a phagocyte recognises a foreign cell
What is the process of phagocytosis?
The phagocyte moves towards the pathogen after detecting chemicals released by it. The pathogen is then engulfed in a vacuole which then fuses with lysosomes which digests the pathogen. The lysosomes are killed and the breakdown of products are then returned to the cytoplasm
What are the properties of the adaptive immune response?
Specificity, diversity, memory and the recruitment of other defence mechanisms
Where are lymphocytes generated?
Primary lymphoid organs
What are examples of primary lymphoid organs?
Thymus, foetal liver and bone marrow
Where is the immune system initiated and the lymphocytes maintained?
Secondary lymphoid organs
What are examples of secondary lymphoid organs?
Lymph nodes and spleen
What are B-lymphocytes?
Differentiated plasma cells that produce antibodies that are specifically designed for the pathogen
What part of the B-lymphocyte is detects the pathogen first?
Membrane bound antibody
Are B-lymphocytes soluble in plasma?
Yes
What is the function of B-lymphocytes?
Make and secrete specifically designed antibodies into the lymph and blood
What are the 5 different types of antibody?
IgG, IgA, IgE, IgM and IgD
What is IgG?
Secondary response
What is IgA?
Mucosal
What is IgM?
Primary response
What is IgE?
Allergy
What is IgD?
No known functions mate
What are antigens?
Proteins that are able to evoke an immune response by reacting with immune products
What are antigen presenting cells?
Phagocytes that display fragments of pathogens on their surface after destroying them
What produces a clone of T-lymphocytes?
Antigen presenting cells
What are T lymphocytes?
Lymphocytes that move to the site of infection via cytokines and are responsible for cell mediated immunity and helping B cells
What must happen to T lymphocytes?
They must be taught not to react to self antigens
What are the 2 types of T lymphocytes?
Th and Tc
What are Th cells?
CD4+ cells that can’t kill pathogens and can activate and direct other immune cells. They come in 2 types: Th1 ad Th2
What is the function of Th1?
They activate Tc cells and macrophages and are involved in type 4 hypersensitivity
What is the function of Th2?
They help B cells produce antibodies and switch IgM to IgE, which is involved in type 1 hypersensitivity
What are Tc cells?
CD8+ cytotoxic T cells that destroy infected cells by inducing apoptosis
How many serum proteins make up the complement system?
25
What are the 3 events involved in the complement system?
Recruitment of inflammatory cells, coating of bacteria and lysis of bacteria
What is the function of cytokines?
They increase the delivery of antimicrobial proteins and clotting elements
What are memory cells?
Cloned B and T cells that were not involved in fighting the infection and survive long term
