Introduction to immunology Flashcards
What is hepatitis?
Hepatitis means inflammation of the liver. Heavy alcohol use, toxins, some medications, and certain medical conditions can cause hepatitis. Hepatitis gives you Cirrhosis. Cirrhosis is a late stage of scarring (fibrosis) of the liver caused by many forms of liver diseases and conditions, such as hepatitis and chronic alcoholism.
What is rheumatoid arthritis?
RA is a chronic disease that causes joint pain, stiffness, swelling and decreased movement of the joints. It is an autoimmune disease in which the immune system erodes cartilage so knuckles grind against each other.
What is multiple sclerosis?
Multiple sclerosis is caused by your immune system mistakenly attacking the brain and nerves. It’s not clear why this happens. It is an autoimmune disease where T and B cells attack the Myelin Sheath which surrounds our nerves. Therefore, you don’t get electrical impulses travelling along the nerves as they should.
What are some infectious agents can cause damage?
- Fungi
- Protozoa
- Multi cellular parasites from dirty water
- Viruses (intracellular: infect entire cell so we would have to kill the whole cell to stop infection from spreading)
- bacteria (extracellular)
What is found in 1ml of human blood?
- Neutrophils: Neutrophils are a type of phagocyte and are normally found in the bloodstream. Part of the innate immune system
- T cells: T cells originate in the bone marrow and mature in the thymus. T cells (also called T lymphocytes) are major components of the adaptive immune system. Their roles include directly killing infected host cells, activating other immune cells, producing cytokines and regulating the immune response.
- B cells: B-cells are the type of cells that produce antibodies to fight bacteria and viruses. These antibodies are Y-shaped proteins that are specific to each pathogen and are able to lock onto the surface of an invading cell and mark it for destruction by other immune cells.
- Macrophage: A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells.
- Monocyte: Monocytes are a type of leukocyte, or white blood cell. They are the largest type of leukocyte and can differentiate into macrophages and conventional dendritic cells.
- Mast cells: Mast cells play an important role in how the immune system responds to certain bacteria and parasites and they help control other types of immune responses. They contain chemicals such as histamine, heparin, cytokines, and growth factors. These have the ability to degranulate. associated with allergy and are full of histamines.
- Dendritic cells: A special type of immune cell that is found in tissues, such as the skin, and boosts immune responses by showing antigens on its surface to other cells of the immune system. A dendritic cell is a type of phagocyte and a type of antigen-presenting cell (APC).
What is the complement system?
Produced in the liver, dissociated very slowly and can be sped up with a bacterial infection. Complement is a system of plasma proteins that can be activated directly by pathogens or indirectly by pathogen-bound antibody, leading to a cascade of reactions that occurs on the surface of pathogens and generates active components with various effector functions. (discussed further in another lecture)
Define the following terms:
- Cyte
- Leuko
- Macro
- Phago
- Poly
- Morph
- Cyte: cell
- Leuko: while
- Macro: big
- Phago: eat
- Poly: many
- Morph: Change shape
What are Auxiliary cells? give some examples
These cells don’t do much. Basophils, mast cells and platelets are all included in this definition. They potentiate an immune response by attracting leukocyte release and mediate inflammation.
What are Eosinophils?
Eosinophils are a type of disease-fighting white blood cell. This condition most often indicates a parasitic infection, an allergic reaction or cancer. You can have high levels of eosinophils in your blood (blood eosinophilia) or in tissues at the site of an infection or inflammation (tissue eosinophilia).
Compare and contrast the innate and adaptive immune system.
You are born with both but your adaptive immune system is the one that will adapt through out your life. Your innate system is the first line defence. The adaptive immune system is more targeted attacks, involving T cell lymphocytes, they also involve the production of antibodies. The innate immune response is activated by chemical properties of the antigen. Adaptive immunity refers to antigen-specific immune response.
The immune system response varies on the pathogen.
What are some examples of the innate immune system?
Anything that secretes:
- Enzymes in tears and skin oils
- Mucus, which traps bacteria and small particles
- Skin.
- Stomach acid
What are phagocytes? give some examples.
These are found in the circulation and reside in the tissue. They engulf, internalise and destroy microorganisms. They include:
- Monocytes
- Neutrophils
- Basophils
- Natural Killer cells
They are able to recognise cells because of pathogen associated molecular patterns (PAMPs)
What are Lymphocytes? give some examples
These initiate the adaptive response and include:
- B cells
- T cells
- NK cells
They produce antibodies and recognise foreign materials, killing cells should they be infected.
What are pathogen associated molecular patterns (PAMPs)?
Phagocytes can recognise pathogens because of these PAMPs. These patterns on the surface allow pathogens to be recognised, the microbe itself cannot live without these patterns. They are sugar or lipids on the microbial surface of a bacterium. Phagocytes will recognise elements of these sugars and bind to it to tigger a phagocytic process, engulfing it and destroying it.
If the PAMPs are not ideal enough for a pathogen to bind to it we can add Opsonic fragments. The opsonisation of a pathogen is to make it more palatable for the phagocytes.
What receptors on phagocytes can detect pathogen associated molecular patterns and opsonisation?
- Scavenger receptors
- Carbohydrate receptors
- Toll-like receptors
