Topic 3: Immunology Flashcards
What does the immune system do?
- Protect against pathogens
- Localise or destroy rapidly dividing cells
- Repair wound or tissue
- Tissue, organ maintenance and homeostasis
- Respond to abnormal or foreign reaction or tissue
What are the components of the immune system?
- Leucocytes
- Thymus
- Lymph nodes
- Spleen
- Tonsils
- Adenoids
- Peyer’s patches
What are the two parts of the immune system?
Adaptive and innate
What does the innate immune system do?
- Non specific response
- Involves physical and chemical barriers to prevent tissue injury and infection
- Activated immediaetly
- Exposure to: noxious material, micro organisms, infectious agents, chemical irritants, tissue injury.
What do mechanical factors in the innate immune system consist of?
Skin Mucous membranes Tears Saliva Gastric juices Urine
What do chemical factors in the innate immune system consist of?
Skin (sebacous secretions, sweat - acidic pH)
Mucous membranes
HCl (stomach)
Lysozymes - breakdown cell walls
Whare are some other non-specific immune responses?
Inflammation - response to tissue injury
Fever - inhibits some temp sensitive microbes and stimulates body’s defence mechanisms
Interferons - proteins that defend against viruses
Complement system - inactive plasma proteins that destroy foreign cells
Natrual Killer cells - important against cancer cells/viruses
What are NK cells?
Natrual Killer cells are lymphocyte like cells that lyse and destroy viruse and cancer cells.
What are symbiotic bacteria?
Exist in the digestive system, on skin and female repro tract.
Synthesise vitamins, inhibit growth of potential pathogens
What is the adaptive immune system?
Has the ability to respond specifically to antigens
Two parts: humoral and cell mediated
What are the three major classes of lymphocytes?
B cells
T cells
Null cells
What is the humoral system made up of?
B cells (B lymphocytes)
Where are B cells produced?
Bone marrow of the long and flat bones
Peyer’s Patches
What are Peyer’s Patches?
Series of elongated thickening of lymphoid tissue in the walls of the intestines near the ileum and colon junction
What are the two main functions of B cells?
Secreting antibodies that bind specifically to antigens
Acting as antigen presenting cells
B cells produce and secrete what?
Antibodies, also known as immunogoblins (Ig) which bring out humoral immunity
Antibodies are the product of what?
B lymphocytes
How are antibodies formed?
When a B cell comes into contact with an antigen, which stimulates the B cell to either mature in to a plasma cell or become a memory cell
What do plasma cells do?
Produce and secrete antibodies
Lives 5 - 7 days
What do memory cells do?
Remain dormant
Form clones ready for repeated attack
Do not participate in current immune attack
What are the five subclasses of antibodies/immunogoblibs?
IgM IgG IgE IgA IgD
What does IgM do?
First antibody secreted Primary AB response Activates complement proteins 5 - 10% in colostrum Large sized molecule so remains in blood vessells
What does IgG do?
Most abundant - second exposure
Produced in large quantities (larger than first)
Enahnces NK cells
80 - 90% in colostrum
Derived from blood
Cross walls of blood vessels and enter tissues
What does IgE do?
Allergic response
Binds to baso/eosinophils and mast cells
