Infectious Disease Introduction Pt. 1 Flashcards
What is the main role of the immune system?
Protects the body from pathogens
What are the characteristics of the immune system?
- Can be specific
- Has memory
- Is mobile and fast acting
- Is flexible (can attack things it has never seen before)
- Hopefully does all this without damage to ourselves
What are the non-specific defenses of the human body? What immune system do they belong to?
Physical barriers (such as the skin)
Chemical barriers (such as stomach acid)
Mucus and cilia protect our respiratory tract
Urine flushes out bacteria from our urinary tract
Enzymes are present in our tears (along with high salt content) and our saliva
Other bacteria is present on our skin and within our digestive tract
Innate Immunity
What are the types of cells of the innate immune system? What do they do?
macrophages, neutrophils (PMNs), monocytes, natural killer cells and eosinophils
These cells act as phagocytes which eat anything that doesn’t belong
Usually rely on receptors on the pathogen or things that coat the pathogen (like antibodies and complements)
What additional function in innate immunity do mast cells and basophils have?
- Phagocytize
- Release inflammatory mediators
Define complement. What are the role of complements?
a complex protein network of plasma, and an integral part of the innate immune system
Can lyse pathogens, coat pathogens, and call for back-up
What is the role of chemokines?
- Act as traffic controllers for WBC’s
What is the role of macrophages and monocytes?
- Antigen presenting cells and surveillance
What are the role of neutrophils?
- Defence against bacteria and fungus
What are the role of eosinophils?
- Defence against parasites and respond to allergies
What are the role of basophils?
- Respond to allergies
In the innate immune system, do all cells respond together?
The innate immune system is non-specific
All cells take part to some degree or another
Do both the innate and adaptive work separately?
No they do not
They work together to fight invading pathogens
What are the two major cells of the adaptive immune system? What makes the adaptive system different than the innate?
- T and B Lymphocytes
- Specific and bale to remember
What are the sub-divisions of the innate immune system?
- Humoral mediated - within the serum
- Cellular mediated - within the cells
Describe the activation of T-lymphocytes
- activated by antigen presenting cell
- activated T cells secrete IL-2 which can stimulate production of more activated T cells
Activated T cells can become….
a) Helper Cells (CD4+)
b) Cytotoxic Cells (CD8+)
c) Regulating Cell
What is the role of Helper cells (CD4+)?
- secrete IL’s and interferon
- stimulates CD8+ cells
- stimulates production of antibodies
What is the role of cytotoxic (CD8+) cells?
- Kill cells recognized as foreign
What is the role of a regulating cell?
- Regulates the T cell response
How are B-lymphocytes activated?
- activated after they recognize antigens (usually through the help of T-lymphocytes)