Quiz 3: Immune System Flashcards
What is an inflammatory response?
- A non specific response to any agent that causes cell injury
- Agents may be:
1) Physical: heat, cold, mechanical
2) Chemical: Concentrated acid
3) Microbiological/Pathogens (Bacterium or virus)
What cells are involved inflammation
1)phagocytes: neutrophils and monocytes that digest harmful substances
2)histamine: A vasodilator
3) platelets: for blood clotting.
What is an infection?
• Inflammation due to disease producing organisms
* “ - itis indicates infection or inflammation
What is sepsis?
Occurs when an infection spreads throughout the bloodstream and body, leading to widespread inflammation. Life threatening condition
What is Adaptive (specific) Immunity?
• Ability of body to defend itself against specific invading agents such as bacteria, toxins, viruses, and foreign tissues
- have specificity and memory
What is an antigen?
Foreign substances that invoke immune responses
Where do B cells mature?
Bone marrow
Where do T cells mature?
Thymus
Two Types of T Cells
1) Cytotoxic T Cells
2) Helper T Cells
Cytotoxic T Cells (T8)
Helper T Cells (T4)
• Regulate function of B cells and cytotoxic T cells
B Cells
Secrete antibodies
What 4 steps happen when foreign antigens enter the body?
1) Antigen processing and presenting
2) Activation of T and B cells
3) Destroy foreign antigens and infected cells
4) Memory cells remain in body
4 Classes of Antibodies
1) IgG:most prevalent during secondary immune response
2) IgA: Found in bloodstream, mucous membranes, and contained in breast milk
3) IgM: First to respond in primary immune response.
4) IgE: Attaches to mast cells and basophils, mediates allergic reactions
Actions of antibodies
- Neutralize antigens
- Immobilize bacteria
- Agglutinate and precipitate antigen for easier digestion by macrophages
-Enhance phagocytosis
-Active complement system
What is hypersensitivity
An abnormal immune response that leads to tissue damage
What are four types of hypersensitivity?
Type I: Immediate
Type II: Cytotoxic:
Type III: Immune complex
Type IV: Delayed hypersensitivity
What is immediate hypersensitivity
- Called allergy and Anaphylaxis
- Immediate hypersensitivity reactions occur when a person encounters specific allergens which triggers an immune response and formation of IgE antibodies
- A person with genetic predisposition to be allergic to something is called atopic
Two examples of immediate hypersensitivity
1) Allergy: Localized response in tissues exposed to allergen
2) Anaphalaxis:Widespread systemic reaction to allergen. Requires immediate treatment with epinephrine
Type II: Cytotoxic Hypersensitivity
- Antibodies (IgG or IgM) are directed against a cell or tissue antigen
- Leads to complement activation (inflammation and attack of cells)
Examples: Incompatible blood transfusion
Type III: Immune complex hypersensitivity
Type IV Delayed hypersensitivity
- Appears 24-48 hours after exposure to allergen
- T4 cells are sensitized after first exposure
- Initialize inflammatory response
Ex: Tuberculosis, fungal and parasitic infections
What is an autoimmune disease
- Group of diseases in which the body forms autoantibodies (antibodies against itself)
- Immune system thinks “self” cells are foreign and attacks them
- The exact etiology of autoimmune diseases is often unknown and is likely multifactorial
What are risk factors for autoimmune diseases
1) Genetics
2) Gender: 80% of people with autoimmune diseases are women
3) Infection:
