1. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

2. THE LYMPHATIC SYSTEM (FIGURE 13-1) What is lymph? Lymphatic vessels and capillaries What is the largest lymph vessel? Slide 2

3. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 3

4. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 4

5. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 5

6. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. THE LYMPHATIC SYSTEM Lymph nodes Filter lymph (Figure 13-4) Located in clusters along the pathway of lymphatic vessels Functions include defense and WBC formation Flow of lymph: to node via several afferent lymph vessels drained from node by a single efferent lymph vessel Slide 6

7. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. THE LYMPHATIC SYSTEM Thymus Lymphoid tissue organ located in mediastinum Total weight of 35 to 40 g—a little more than an ounce Plays a vital and central role in immunity Produces T-lymphocytes, or T cells Secretes hormones called thymosins Lymphoid tissue is largely replaced by fat in the process called involution Slide 7

8. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. THE LYMPHATIC SYSTEM Tonsils (Figure 13-7) Composed of three masses of lymphoid tissue around the openings of the mouth and throat Palatine tonsils (“the tonsils”) Pharyngeal tonsils (also known as adenoids) Lingual tonsils Subject to chronic infection Enlargement of pharyngeal tonsils may impair breathing Slide 8

9. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 9

10. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. THE LYMPHATIC SYSTEM Spleen Largest lymphoid organ in body Located in upper left quadrant of abdomen Often injured by trauma to abdomen Surgical removal called splenectomy Functions include phagocytosis of bacteria and old RBCs; acts as a blood reservoir Slide 10

11. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. IMMUNE SYSTEM CELLS Lymphocytes Most numerous of immune system cells Development of B cells—primitive stem cells migrate from bone marrow and go through two stages of development (Figure 13-12) First stage—stem cells develop into immature B cells; takes place in the liver and bone marrow before birth and in the bone marrow Second stage—immature B cell develops into activated B cell; initiated by immature B cell’s contact with antigens, which bind to its surface antibodies; activated B cell, by dividing repeatedly, forms two clones of cells—plasma cells and memory Slide 11

12. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 12

13. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 13 Development of T cells—stem cells from bone marrow migrate to thymus gland (Figure 13-13) Stage 1—stem cells develop into T cells; occurs in thymus during few months before and after birth; T cells migrate chiefly to lymph nodes Stage 2—T cells develop into sensitized T cells; occurs when, and if, antigen binds to T cell’s surface proteins

14. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 14

15. Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. IMMUNE SYSTEM CELLS Lymphocytes (cont.) Function of B cells—indirectly, B cells produce humoral immunity; activated B cells develop into plasma cells; plasma cells secrete antibodies into the blood; circulating antibodies produce humoral immunity (Figure 13-12) Functions of T cells—produce cell-mediated immunity; kill invading cells by releasing a substance that poisons cells and also by releasing chemicals that attract and activate macrophages to kill cells by phagocytosis (Figures 13-14 and 13- 15) Slide 15

16. Lymph System

17. Term Twister is a terminology game for seminar. Use the terms from the current unit’s terminology list. Scramble the words. Use one term per slide. The first slide has the only the scrambled term. The next slide has both the scrambled term and then the unscrambled solution followed by the definition. Ask students to unscramble the term and give the definition in their own words. Then, show the second slide with the solution.

18. Hplym

19. Lymph specialized fluid involved in the filtering of organisms and other potentially harmful substances

20. sleytmpchyo

21. Lymphocytes most numerous cells of the immune system; among other functions, they may become plasma cells that produce antibodies

22. negtian

23. Antigen a substance, often a protein, that can elicit an immune response

24. cificeps ytinummi

25. Specific immunity adaptive immunity; involves “memory” and the ability to recognize specific harmful substances or organisms

26. einmum mseyst

27. Immune system the body’s specific defense mechanism against disease

28. mphly sedon

29. Lymph nodes specialized structures of the immune system involved in the “filtering” process

30. Stlonsi

31. Tonsils masses of lymphoid tissue located in the mouth and throat

32. Nslepe

33. Spleen largest of the lymphoid organs; involved in filtering the blood to remove harmful substances and old blood cells

34. Boanditise

35. Antibodies immunoglobulins; proteins involved in the immune response

36. Setycogaph

37. Phagocytes cells of the immune system that are able to engulf and digest foreign substances and organisms

38. Thanks for playing Term Twister!