Disorders of the immune system Flashcards
Explain what is meant by ‘allergy’
Allergy is an overactive or misdirected immunity The immune system overacting to either a food or substance. A person experiencing multiple allergies are known as atopic.
Describe some aetiologic triggers of type I hypersensitivity reactions
Pollen Animals Dust Foods Caffiene
Describe the clinical differences between systemic and local type I hypersensitivity reactions
Systemic-This is when the allergy affects the whole body, so the mast cells around the body are activated.
Local-in a certain area
Name some of the drugs used to combat allergic reactions and describe their mode of action
Antihistamine-block the effects of the anti histamine
Sulbutamol-Salbutamol is a type of medicine called a bronchodilator. It works by relaxing the muscles of the airways into the lungs, which makes it easier to breathe.
Corticosteriods -reduces inflammation because it blocks the production of prostaglandins
Rapid adrenaline-When injected, adrenaline rapidly reverses the effects of anaphylaxis by reducing throat swelling, opening the airways, and maintaining heart function and blood pressure.
Describe in detail the pathophysiology underlying an anaphylactic reaction
Anaphylaxsis is a severe,life threatening generalised or systematic hypersentivity reaction, that cause significant disturbance to airway,breathing and circulation.
This occurs because the immune system reacts inappropriately in response to the presence of a food or substance that it perceives as a threat.Anaphylaxis results from the degranulation of mast cells and basiophils.This degraulation is caused by the cross linking of IgE bound to to memebrane high affinity IgE receptor.Skin may itch,swelling,abdominal pain,nausea,vomiting,diarrhoea.
Explain what is meant by the term ‘primary immunodeficiency disease’
Being born with immune system defects/congenic
Describe the detailed pathophysiology of Chronic Granulomatous Disease (CGD).
A genetic disease,which is caused by the defects of NADHP oxidase(NOX).This defect results in the inability of phagocytes to engulf microbes.NOX produce ROS that it pumped into phagosome and aids in the ingestion of microbes.
