What are you two defenses against microbes?
- 1.) Innate (non-immune and non-specific)
- 2.) Immune
What differentiates the immune system from other body systesm?
- The tissues and organs in this system are NOT directly connected.
- It is also associated with the circulatory system (mobility) and the nervous system.
Zinc's definition of the immune system...
"A dispersed collection of cells, tissues & organs, functioning to defend the organism from foreign invasion."
What are the components of the immune system?
- 1.) Spleen
- 2.) Lymph nodes
- 3.) bone marrow
- 4.) Thymus
- 5.) MALT*
What is MALT comprised of and where are they located?
- *Mucous associated lymphoid tissue*
- Lining all lumens with access to the outside world.
- 1.) Tonsils (2 in nasal passages, 2 in throat, 1 at base of tongue)
- 2.) Appendix (off of the large intestine)
- 3.) Peyer's patches (in the wall of the small intestine)
What function do the MALT organs serve?
They contain immune cells that keep the body's microbial populations at controllable numbers.
How can large numbers of bacteria cause a problem in the body?
They produce large amounts of toxic metabolic waste.
Aside from the small intestine, where else are Peyer's patches expected to exist?
The lining of the respiratory, reproductive, and urinary system.
Why are the MALT organs located just underneath mucous linings?
- Mucous is not 100% effective at trapping invaders.
- MALT organs are the next line of defense.
List the functions of the Spleen.
- 1.) Stores excess erythrocytes (physiological)
- 2.) Repair usable erythrocytes (physiological)
- 3.) Principle center for antibody production (immunological) - the spleen filters blood for the presence of foreign organisms
*RBC's live for about 120 days.
A protein with the ability to bind a specific structure on the surface of a foreign organism.
What are lymph nodes?
- Pea sized structures located all over your body (mostly in the trunk) that filter interstitial fluid.
- They number in the thousands.
How much interstitial fluid enters the lymph system (rather than being absorbed back into circulation)?
Why is bone marrow an immune organ?
It produces all of the body's blood cells, including the white blood cells (leukocytes).
What is the function of the Thymus?
It is the principle center for the maturation of T-cells.
What is the difference between WBC's and immune cells?
All immune cells are leukocytes, but not all leukocytes are immune cells.
What is another name for immune cells?
List the types of lymphocytes.
- 1.) B-cells
- 2.) T-cells
- 3.) NK (natural killer) cells
Where do B-cells originate and mature?
In the bone marrow.
Where do T-cells originate and mature?
T-cells originate in the bone marrow and mature in the Thymus.
List the body's leukocytes (excluding lymphocytes).
- 1.) Basophils
- 2.) Neutrophils
- 3.) Eosinophils
- 4.) Platelets
- 5.) Mast cells
- 6.) Macrophages
What is the function of platelets?
What is the function of Mast cells?
To initiate the inflammatory response.
- * They are found everywhere in the body (as they travel through circulation).
- * They are produced in the bone marrow and in the liver.
What is the body's "clean-up and healing process?"
The inflammatory response.
What do Mast cells produce to initiate the inflammatory response (as a result of injury, for ex.)?
What effects do histamines have on the body?
- 1.) Dilate blood vessels
- 2.) Increase permeability of blood vessel walls
- 3.) Recruit important cells to area
- 4.) Contraction of non-vascular smooth muscle*
True or false?
The immune response is not the same as the inflammatory response.
- But they do go "hand in hand."
What function do Basophils serve?
- Initiation of the inflammatory response (with histamines).
- However, they do not leave the blood. Therefore, they are suspected to be messenger cells as well.
- Comprise 0.5% of WBC's.
What functions do neutrophils serve?
- They are phagocytic cells.
- They are the most abundant WBC, comprising about 60%.
What function do eosinophils serve?
- Defend against parasites (particularly helminths).
- They contain potent digesting enzymes and can be somewhat phagocytic.
- Comprise 1-3% of WBC's.