Immune System Flashcards
What is an antigen?
An antigen is any cell or substance that stimulates an immune response.
What are antigens?
Antigens are toxins, chemicals, bacteria, viruses or other substances from outside the body.
What is a non-specific defence?
Epithelial barriers
Phagocytes
Antimicrobial chemicals
Inflammatory response
Immunological surveillance
What are the two defence mechanisms?
Non-specific and specific
What are examples of a non-specific mechanisms?
Cells, chemicals and physical barriers that are present at birth.
What are examples of a specific mechanisms?
Activated by the presence of microbes.
Collection of organs, cells and chemicals that generate cells and antibodies for a specific target
what are Epithelial barriers?
Healthy, intact skin:
- Bacteria
- Sebum and sweat contain antibacterial and antifungal substances.
- Epithelial membranes
- Nose hairs
- Urine flow and vaginal secretions
what are phagocytes? And what do they do?
-Neutrophils and macrophages. WBC.
Migrate to inflammation and infection - engulf, digest and destroy foreign, antigenic and damaged body cells.
What happens to neutrophils when they are activated and phagocytosing?
Destroy themselves and their target.
Macrophages (WBC) what are they and what do they do?
- Longer lifespan than neutophils.
- Response to an infection.
- After destroying the antigen they display fragments to stimulate T cells
- Promote inflammatory response, induce fever and healing.
Name all 6 antimicrobial chemicals?
Hydrochloric acid
Lysozyme
Antibodies
Saliva
Interferons
Complement (plasma proteins)
Hydrochloric acid
- Present in gastric juice
- It kills swallowed microbes.
- pH is 1 - 2
- Some meds can reduce acidity which makes someone more susceptible to GI infections.
Lysozyme
- Antibacterial enzyme
- Found in granulocytes
- NOT found in sweat, urine or CSF (fluid in the brain)
- Destroys bacterial cell wells.
What are the 3 granulocytes?
Basophil, Neutrophil and Eosinophil
Antibodies
- Protective proteins
- Bind to destroy antigens
- Found in all body fluids
- Coat membranes that are exposed to external environment; Genitourinary tract, respiratory tract and GI tract.
Saliva
- Secreted into the mouth
- Washes away food debris - could encourage bacterial growth.
- Contains antibodies.
Interferons
- Produces and released into local tissues by T cells, macrophages and virus infected body cells.
- Reduce the spread of viruses to healthy body cells.
Complement
- about 20 proteins found in blood and tissues.
- Activated by immune complexes (antibody + antigen)
- Destroys bacteria
- Stimulates phagocytosis.
- Chemoattractant
What is the purpose of Inflammatory response? signs of inflammation?
Purpose is protective, help healing. Signs are, redness, heat, swelling and pain.
What is acute inflammation? what are the effects?
Short duration.
Effects:
- Increased blood flow
- Tissue fluid
- Migration of WBC
- Raised temp
- Pain
- Suppuration (pus)
What are immunological surveillance
Lymphocytes
What are immunological surveillance
Lymphocytes
