1. IMMUNE/LYMPHATIC SYSTEM

2. What is an infectious disease?
Pathogens = disease-producing agents
Not all microorganisms are pathogenic
Microorganisms live on skin, in the intestines, upper respiratory tract, lower urinary tract, reproductive tract, etc…
Some have symbiotic relationships with our bodies, help maintain equilibrium

3. In order for pathogens to enter… they must first penetrate your skin
They will encounter the body’s secretions (sweat, oil, mucus, tears, saliva)
Main function of mucus is to prevent areas from drying out. It also traps microorganisms

4. Mucus is continually swallowed and passed to the stomach where acidic gastric juice destroys it
Sweat, tears, saliva all have the enzyme lysozyme (breaks down cell walls of some bacteria)

5. Your skin is a part of your first line of defense against pathogens
Your skin is a part of your first line of defense against pathogens. It is included in the category titled “non-specific defense mechanisms”
The first line of nonspecific defense = external
The second line of nonspecific defense = internal. They indiscriminately attack invaders that penetrate the body’s outer barriers.
The third line of defense (the immune system) responds in a specific way to particular substances marked by foreign molecules.

6. Inflammation of body tissue
Inflammation is an example of a second line of defense kicking in.
Redness, swelling, pain, and heat
Cells damaged by invading microbes release chemical signals that attract white blood cells called phagocytes
A neurotransmitter generated by white blood cells, histamine, is released and causes blood vessels to dilate in that area

7. The steps taken by white blood cells (phagocytosis)
The pus that accumulates at the site of some infections consists mostly of dead phagocytic cells, fluid, and proteins that leaked from capillaries during the inflammatory response.

8. Phagocytosis of pathogens
Phagocytes take action. They are white blood cells that destroy pathogens by surrounding and engulfing them
Specific examples = monocytes, macrophages, neutrophils

9. Some macrophages (phagocytes) migrate throughout the body, while others reside permanently in certain tissues.

11. Lymphatic system
Helps body defend itself against disease & maintains homeostasis by keeping body fluids at a constant level

12. Glands of the lymphatic system
Lymphocyte = type of white blood cell that defends the body against foreign substances
B lymphocytes (B cells)- make antibodies against antigens. Memory cells.
T lymphocytes (T cells)- play a role in cell mediated immunity (no antibodies). Killer T, Helper T, ect. Made in Thymus.
Both types of lymphocytes circulate throughout the blood and lymph and are concentrated in the spleen, lymph nodes, and other lymphatic tissue.

13. Glands of the lymphatic system
Lymph nodes = small mass of tissue that contains lymphocytes and filters pathogens from the lymph
Made of interlaced network of connective tissue fibers that hold lymphocytes

14. Antigens (foreign molecules) are identified by B cells
Antigens (foreign molecules) are identified by B cells. The B cell with the correct antibody receptor on its antibody then duplicates.

16. More Glands of the lymphatic system
Tonsils are larger clusters of lymph tissue located at the back of the mouth cavity and throat
They produce lymphocytes & protect the throat from potential infections
normal
swollen

17. Glands of the lymphatic system
Spleen = another organ that stores lymphocytes
It filters out and destroys bacteria & worn-out red blood cells

18. Glands of the lymphatic system
Thymus gland = stores immature lymphocytes until the are ready to be released into the body’s defense system
Spleen

19. Endocrine Disorders
Turner Syndrome
PKo
Pituitary Gigantism
A9A