1. Chapter Fourteen Immunity

2. Functions
The lymphatic system is composed of a network of vessels that collect and carry away excess fluid from interstitial spaces and transport fats to the circulatory system.

3. Pathways
Lymphatic pathways start as lymphatic capillaries that merge to form larger vessels, that empty into the circulatory system.

4. Lymph
Lymphatic capillaries are tiny, closed-ended tubes receive tissue fluid called lymph.

5. Structure
Larger lymphatic vessels pass through lymph nodes and merge to form lymphatic trunks.

6. Tissue Fluid Tissue fluid is made up of water and
dissolved substances that leave blood
capillaries by filtration and diffusion.

7. Filtration
Some smaller proteins leak from capillaries into the tissues and are not returned to the bloodstream.

8. Movement
The change in tissue fluid causes a change in osmotic pressure and causes the lymph to move.
Edema can cause a disruption in the movement of lymph.

9. Lymph Nodes
Lymph nodes, which contain lymphocytes and macrophages (clean up the lymph), are located along lymphatic pathways. They are bean-shaped, with blood vessels, nerves, and efferent lymphatic vessels.

10. Lymph nodes are also centers of lymphocyte production

11. Thymus
soft, bi-lobed organ located behind the sternum; it shrinks in size during the lifetime.

12. Thymus
Produces Lymphocytes that eventually leave the cell and become T cells that help with immunity.

13. Spleen
The body’s largest lymphatic organ that contains blood instead of fluid.

14. Spleen
Inside the spleen lies white pulp (containing many lymphocytes) and red pulp (containing red blood cells, macrophages, and lymphocytes).
The spleen filters the blood and removes damaged blood cells and bacteria.

15. Defense The body has two types of defense
Nonspecific defense would guard against a pathogen
Specific defense would guard against a specific target.

16. Species Resistance
A species is resistant to diseases that affect other species because it has a unique chemical environment or temperature that fails to provide the conditions required by the pathogens of another species.

17. Nonspecific Resistance
Species Resistance
Mechanical Barriers (skin, mucous membrane)
Chemical Barriers (gastric juice, interferons.)

18. 4. Fever
Fever interferes with the proper conditions that promote bacterial growth.
a.Iron is reduced to cut off nutrients to pathogens
b.Phagocytic cells are more active when temp rises

19. 5.) Inflammation
tissue response to a pathogen, is characterized by redness, swelling, heat, and pain.
This is caused by a increase of blood to the area to flood it with white blood cells.

20. 6.) Phagocytosis
-Neutrophils engulf smaller particles; monocytes attack larger ones.
- Monocytes give rise to macrophages, which become fixed in various tissues

21. Specific Responses
Antigens are made so the body can recognize itself from foreign particles.

22. B Cells
These cells are thought to mature in the bone marrow. They produce and secrete antibodies that react with foreign antigens.

23. T Cells
These cells undifferentiated until they reach the thymus and then they interact directly with the foreign antigens.

24. Humoral Defense
Body fluids attack and destroy specific antigens or antigen-bearing particles through antibody-mediated immunity.

25. Activation
For T cells to be activated they must encounter another cell that has encountered the antigen.

26. Helper T Cells
Once they come in contact with a macrophage with the right proteins they will activate B cells to produce antibodies.

27. Cytotoxic T Cells
Monitor the bodies cells by recognizing and eliminating tumor cells and virus-infected cells by release of proteins.

28. Memory T Cells
provide a no-delay response to any future exposure to the same antigen.

29. Immunity Classification
1. Naturally acquired active immunity occurs after exposure to the antigen itself.
2. Artificially acquired active immunity occurs through the use of vaccines, without the person becoming ill from the disease.

30. 3. Artificially acquired passive immunity
3. Artificially acquired passive immunity involves the injection of gamma globulin containing antibodies and is short-lived.
4. Naturally acquired passive immunity
occurs as antibodies are passed from mother to fetus and is short-lived.

31. Autoimmunity
1. In autoimmune disorders, the immune system manufactures antibodies against some of its own antigens.
2. Autoimmune disorders may result from viral infection, faulty T cell development, or reaction to a nonself antigen that bears close resemblance to a self antigen.