1. © 2010 Delmar, Cengage Learning 1 PowerPoint Presentation to Accompany

2. © 2010 Delmar, Cengage Learning 2 Chapter 15 The Lymphatic System

3. © 2010 Delmar, Cengage Learning 3 Introduction Transports lymph through lymphatics Lymphatics: lymph capillaries and vessels Controls body fluid Destroys harmful microorganisms

4. © 2010 Delmar, Cengage Learning 4 4 The Functions of the System and the Structure and Functions of the Lymphatic Vessels

5. © 2010 Delmar, Cengage Learning 5 Introduction Drain interstitial fluid from tissue spaces –Prevent edema Transport digested fat to blood –Lacteals: special lymphatics in small intestine –Chyle: milky lymph in lacteals Develop immunities Produce lymphocytes

6. © 2010 Delmar, Cengage Learning 6 Lymphatic Vessels Lymph capillaries: blind-end tubes Lymph capillaries are located between cells Lymph capillaries unite to form lymphatics Lymphatics converge into two main channels –Thoracic duct and right lymphatic duct

7. © 2010 Delmar, Cengage Learning 7 Lymph Nodes Found along lengths of lymphatics Efferent: exit lymph node at the hilum Afferent: enter lymph node at various locations Trabeculae: divide the node into compartments Germinal centers of compartments produce lymphocytes

8. © 2010 Delmar, Cengage Learning 8 8 Lymph Circulation

9. © 2010 Delmar, Cengage Learning 9 Lymph Circulation (cont’d.) Interstitial fluid: plasma in interstitial spaces Lymph: interstitial fluid in lymph capillaries –Passes into lymphatics Lymphatics join to form lymph trunks

10. © 2010 Delmar, Cengage Learning 10 Lymph Circulation (cont’d.) Lymph circulation maintained by: –Normal skeletal muscle contractions Compresses lymph vessels and forces lymph in one direction –Respiratory or breathing movements –Smooth muscle in lymphatic vessels

11. © 2010 Delmar, Cengage Learning 11 Lymph Circulation (cont’d.) Lymph trunks –Lumbar: drains lower extremities and pelvis –Intestinal: drains abdominal region –Bronchomediastinal and intercostal: drain thorax –Subclavian: drains upper extremities –Jugular: drains head and neck

12. © 2010 Delmar, Cengage Learning 12 Lymph Circulation (cont’d.) Individual trunks drain into two main trunks –Thoracic duct: drains into the left subclavian vein –Right lymphatic duct: drains into the right subclavian vein

13. © 2010 Delmar, Cengage Learning 13 © 2010 Delmar, Cengage Learning 13 The Organs of the Lymphatic System

14. © 2010 Delmar, Cengage Learning 14 The Organs of the Lymphatic System (cont’d.) Tonsils –Palatine, pharyngeal and lingual –Protect the nose and oral cavity Thymus: lymphocyte production and maturation Peyer’s patches: found in walls of small intestine

15. © 2010 Delmar, Cengage Learning 15 The Organs of the Lymphatic System (cont’d.) Spleen –Largest mass of lymphatic tissue –Phagocytizes worn-out RBCs and platelets Recycles hemoglobin –Produces lymphocytes and plasma cells –Stores blood for release during hemorrhage

16. © 2010 Delmar, Cengage Learning 16 The Organs of the Lymphatic System (cont’d.) External view of the Spleen

17. © 2010 Delmar, Cengage Learning 17 © 2010 Delmar, Cengage Learning 17 Immunity

18. © 2010 Delmar, Cengage Learning 18 Immunity (cont’d.) Ability of body to resist –Infection from pathogens –Damage from foreign substances and harmful chemicals Humoral immunity –B lymphocytes: produce antibodies Fight circulating bacteria and viral infections Become plasma cells when they enter tissues

19. © 2010 Delmar, Cengage Learning 19 Immunity (cont’d.) Cellular immunity –T lymphocytes Come from thymus glands Fight intracellular viruses, fungi, parasites, cancer

20. © 2010 Delmar, Cengage Learning 20 © 2010 Delmar, Cengage Learning 20 Antigens and Antibodies

21. © 2010 Delmar, Cengage Learning 21 Antigens and Antibodies (cont’d.) Antigen: foreign protein in our body B lymphocytes –Produce antibodies in response to antigens –Antibodies bind to specific antigen –Antigens precipitate –Phagocytic WBCs eat the antigens

22. © 2010 Delmar, Cengage Learning 22 Antigens and Antibodies (cont’d.) Antibody morphology –Four amino acid chains linked by disulfide bonds Heavy and light chains –Y shaped molecule –Binding sites at tips of Y –Stem of the Y is always constant

23. © 2010 Delmar, Cengage Learning 23 Antigens and Antibodies (cont’d.) Antibody types –IgG: attacks viruses, bacteria, and toxins; activates complement –IgA: found in exocrine gland secretions –IgM: response to bacteria or food antigens –IgD: found on surface of B lymphocytes –IgE: associated with allergic reactions

24. © 2010 Delmar, Cengage Learning 24 Antigens and Antibodies (cont’d.) Active immunity: B cells contact antigen and produce antibodies –Natural active: exposure to infection –Artificial active: vaccine Passive immunity –Natural passive: maternal antibodies to fetus –Artificial passive: gamma globulin

25. © 2010 Delmar, Cengage Learning 25 © 2010 Delmar, Cengage Learning 25 Cells of the Immune Response and Other Defenses

26. © 2010 Delmar, Cengage Learning 26 Cells of the Immune Response and Other Defenses (cont’d.) B cells: antigen –Antibody binding Plasma cells: replicated B cells Helper T cells: stimulate production of –Killer T cells –More B cells

27. © 2010 Delmar, Cengage Learning 27 Cells of the Immune Response and Other Defenses (cont’d.) Killer T cells: –Attack virus-invaded body cells –Attack cancer cells –Reject body grafts Memory cells: descendents of activated T and B cells Suppressor T cells: slow down activities of B and T cells

28. © 2010 Delmar, Cengage Learning 28 Cells of the Immune Response and Other Defenses (cont’d.) Macrophages –Engulf and digest antigen –Present then to T cell for recognition

29. © 2010 Delmar, Cengage Learning 29 Cells of the Immune Response and Other Defenses (cont’d.) Lymphokines: chemicals released by sensitized T cells Monokines: chemicals released by activated macrophages Skin: mechanical barrier –Acid mantle, sebum Lysozyme: (tears and saliva) attacks bacteria

30. © 2010 Delmar, Cengage Learning 30 Cells of the Immune Response and Other Defenses (cont’d.) Mucous membranes: trap microorganisms and debris Hydrochloric acid: (stomach) destroys microorganisms

31. © 2010 Delmar, Cengage Learning 31 Animation – Lymphatic System [Insert Lymph.swf]

32. © 2010 Delmar, Cengage Learning 32 Summary Discussed the functions of the immune system Described lymph and its flow through the body Discussed the functions of the spleen and tonsils Described the different types of immunity Discussed the immune response