immune system review Flashcards
first line of defence
- physical and chemical barriers
- intact skin
- mucous membrane and their secretions
second line of defence
- phagocytosis white blood cells
- inflammation and fever
- antimicrobial substances
third line of defence
- specialized lymphocytes (B & T cells)
- antibodies
self recognition
can cause complications for medical procedures such as tissue grafts, tissue and organ transplants, and blood transfusions
what 3 main things does the body need to be able to do to defend itself?
- recognize its own tissues
- ignore its normal microflora
- eliminate abnormal cells
what type of disease results when the self recognition system fails?
- autoimmune disorders
- celiacs or diabetes
MHC
- major histocompatibility complex
- MHC molecules are used by the immune system to recognize its own and foreign material
why must the MHC be matched for organ/tissue transplants?
foreign MHC molecules contain different antigens, causing the immune system to attack the foreign cells
microflora
bacteria that doesn’t cause disease
eosinophils
produce toxic proteins against certain parasites, and some phagocytes
basophils
release heparin and histamine which promotes inflammation
neutrophils
these cells engulf and destroy foreign material
e.g.) bacteria
benefits of a fever:
- intensifies the effect of interferons
- increases the production of t-cells
- speeds up metabolic reactions increasing the rate of tissue repair
- increases heart rate so white blood cells are delivered to site of infection quicker
what causes the body to change its set point to cause a fever
the most common cause is infections from viruses and bacteria
