Immunology and Anaphylaxis Flashcards
Tissues and organs of the immune system
• Tonsils and Adenoids
• Thymus
• Lymph nodes
• Spleen
• Peyer’s patches
• Appendix
• Lymphatic vessels
• Bone marrow
Immune Priviledged sites:
• Eyes
• Placenta and Foetus
• Testicles
• Central Nervous System
What does the immune system do?
• recognise and neutralise pathogens
• recognise and kill infected cells
• respond to “danger” signals
•Surveillance and removal of transformed (pre-cancerous or cancerous cells)
• removes dead cells
Contribute to wound healing
Reaction or symptoms of IgE allergic reaction
• systemic anaphylaxis
• acute urticaria
• seasonal rhinoconjunctivitis
• asthma
• food allergy
Allergic Asthma symptoms:
• shortness of breath/breathing
• cough (day or night)
• wheezing
• chest tightness
Allergic Rhinitis symptoms:
• inflammation in the nostrils due to presence of an allergen (environment)
• itchy eyes/throat
• sneezing, blocked/runny nose
• watering, red eyes (allergic conjunctivitis)
• shortness of breath
• tiredness
• post-nasal drip
What can trigger a reaction of systemic anaphylaxis?
• drugs (penicillin, insulin, and antitoxins)
• foods
Can be fatal
What is the most severe type of anaphylaxis
• systemic anaphylaxis
• often fatal and occurs within minutes of exposure
How is an allergen introduced into the body
• directly into the blood stream
• absorbed into the circulation from the gut or skin
Symptoms of anaphylaxis
• precipitous drop in blood pressure leading to anaphylactic shock
• this would cause contraction of smooth muscles to defecation, urination and bronchioles constriction causing laboured respiration.
Symptoms of anaphylaxis are due to:
• rapid and widespread IgE antibody-mediated degranulation of mast cells and basophils and the systemic effects of their contents
What treatment is used for systemic anaphylactic reactions?
• adrenaline
• it counteracts the effects of mediators such as histamine and leukotrienes, relaxing smooth muscles of the airways and reducing vascular permeability
Oxygen
Hydrocortisone
Adrenaline improves:
Improves cardiac output, which is necessary to prevent vascular collapse
What is the role of white blood cells
• leukocytes protect against diseases, microbes and other foreign invaders
What are the three subtypes of white blood cells
• granulocytes
• lymphocytes
• monocytes
Granulocytes consist of
• neutrophils
• eosinophils
• basophils
What is a neutrophils main target
• bacteria and funghi
What is a eosinophils main target
• larger parasites, and modulate allergic inflammatory response
What is the function of basophils
• release histamine for inflammatory response
T-cells are
• Cell mediated
• cytotoxic adaptive immunity
B-cells are
• humoral
• antibody immunity
Natural killer (NK) cells are..
• depend against tumours and virally infected cells
• include macrophages
What is type 1 hypersensitivity
• IgE mediated
most common type of hypersensitivity reaction
• immediate or anaphylactic hypersensitivity
• more commonly known as allergy
Type 1 hypersensitivity is provoked by
• re-exposure to a specific type of antigen
• eg. Pollen, pet dander, food allergens
Type 1 hypersensitivity immune mechanism:
• mediated by IgE antibodies bound to Fc receptions on cells such as mast cells
IgG function:
Main form of antibodies. Production increased after immunisation, secreted during secondary response
IgA function:
• Main antibody types in external secretions, such as saliva and mothers milk
IgE function:
• responsible for allergic symptoms in mediate hypersensitivity reactions
IgM function:
• Function as antigen receptors on lymphocyte surface prior to immunisation; secreted during primary response
IgD function:
• function as antigen receptors on lymphocyte surface prior to immunisation; other functions unknown
Antibodies can inactivate the invading pathogen directly by:
• agglutination
• precipitation
• neutralisation
• lysis
Immune mediator in allergy and Atopic hypersensitivity
IgE
