1. Lymphatic System Tissues organs, vessels and a fluid called lymph
similar to interstitial fluid
Diffuse lymphatic tissue
Tonsils, mucosa associated lymph tissue and red bone marrow
Lymph Organs
thymus
spleen
lymph nodes
Lymphocytes for Immunity

2. Functions of the Lymphatic System
Draining excess interstitial fluid & plasma proteins from tissue spaces
Transport of some nutrients and hormones
Immunity –specific defense
recognize microbes or abnormal cells & responding by killing them directly or secreting antibodies that cause their destruction

3. Formation & Flow of Lymph
Some fluid & proteins Filtered from blood capillaries are collected by lymphatic capillaries & returned to the blood
Muscle contraction and breathing promote flow of lymph
Lymphatic vessels empty into subclavian veins in shoulders

4. Lymph Circulation Lymph capillaries
Capillaries are closed-ended tubes in tissues
Have one-way minivalves
Pickup fluid (lymph) from Tissues (interstitial fluid)

5. Lymph Capillaries
Comparison of Lymph and Blood Capillaries
Minivalve

6. Lymph Circulation Lymphatic Vessels (lymphatics)
Lymph passes from capillaries into lymph vessels
Resemble veins with thin walls & valves
Afferent lymphatics carry lymph to nodes
Efferent lymphatics carry lymph from nodes

7. Lymph Circulation
Afferent, Efferent Lymphatics and Valves

8. Lymph Circulation Lymph trunks drain lymph into ducts
Lymph ducts - largest lymph channels
Two ducts drain lymph into subclavian veins
Larger thoracic duct drains most of body
Smaller right duct drains right side head, right shoulder and right arm into right subclavian vein

9. Lymph Ducts
Right Lymphatic Duct
Thoracic Duct

10. Lymph circulation
Drainage Pattern of Lymphatic Ducts

11. Summary of Lymphatic Flow
Interstitial fluid  Lymph Capillaries 
Afferent Lymphatics  Lymph Nodes 
Efferent Lymphatic  Lymphatic Trunks
 Lymphatic Ducts  Subclavian Veins of cardiovascular system (CVS)

12. Which are the larger lymphatic structures?
Question
Which are the larger lymphatic structures?
(A) lymphatics
(B) trunks
(C) capillaries
(D) ducts

13. Lymph Tissues
Lymphatic nodules – MALT (Mucosa Associated Lymph Tissues)
lymphatic nodules within the digestive and respiratory systems
Small intestine
Appendix
Bronchi of respiratory tract

14. Lymph Tissues Tonsils Located in and around throat Tonsilar crypts
Functions
Crypts Trap microbes such as bacteria
Mount immune response against inhaled and ingested microbes

15. Lymph Organs Lymph nodes Structure Location Functions
Throughout body but concentrated in groin, neck, armpit
Functions
Filter lymph
Provide immunity

16. Lymph Node Distribution
Cervical Nodes
Axillary Nodes
Inguinal Nodes

17. Vessels that enter lymph nodes are called ______ lymphatics.
Question
Vessels that enter lymph nodes are called ______ lymphatics.
(A) efferent
(B) afferent
(C) enter
(D) endo

18. Lymph Organs Thymus Located in mediastinum above heart
Large in infants atrophying with age
Function
Thymosin hormones for
T-cell lymphocyte maturation

19. Spleen Located in upper left quadrant to left of stomach Functions
Filters blood
Provides immunity
Stores iron and platelets

20. Question
Which of the following are located within the intestinal lining?
(A) tonsils
(B) lymph nodes
(C) thymus glands
(D) MALT

21. Question
What lymphatic structure contains hormones for T-cell lymphocyte maturation?
(A) Tonsils
(B) Thymus gland
(C) Spleen
(D) MALT

22. Defense Non-specific Defense First Line Defense: External Skin
Mucous Membranes
Tears
Saliva
Stomach acid

23. Non-specific Defense Second Line Defense: Internal
Antimicrobial proteins
Interferons – antiviral
Complement – immunity and inflammation
Natural killer (NK) cells
Lymphocytes
Kill microbes and tumor cells
Phagocytes
Wandering phagocytes
Fixed phagocytes

24. Internal Defense Inflammation
Mast cells and basophils release chemicals including histamine
Arterioles vasodilate – more blood to site
Increased capillary permeability – more fluid into tissues

25. Internal Defense
Results in
Redness
Heat
Swelling (edema)
Pain
Healing

26. Question
Which of the following is a first-line of non-specific defense?
Interferons
mucous membranes
NK cells
Inflammation
none of the above

27. Specific Defense: Immunity
Study of immunity is immunology
Immunity versus non-specific defense
Specificity: responds to specific invaders
Destroys invaders by various means such as: ___________________________
Memory: Second exposure to antigen causes a stronger response

28. Antigens
Foreign (non-self) cells or chemicals that produce an immune response (stimulate antibody production)
Are microbes, parts of microbes, blood cells, transplant tissues, and a variety of chemicals

29. Immunity B-cell and T-cell lymphocytes responsible for immunity
Two types of immune responses
Cell mediated immunity: T-cells respond to intracellular antigens such as virus infected cells and tumor cells
Antibody mediated immunity: B-cells respond to extracellular antigens
Antibodies combat the antigen

30. Cell Mediated Immunity
T-cells originate in the red bone marrow and are processed (undergo maturation) in the thymus gland
Matured T-cells then pass into other lymph tissues where they are ready to respond to antigens

31. Immunity Two types of T-cell lymphocytes CD8 cells CD4 cells
Activated by contact with virus infected body cell
Onr type develops into killer T-cells and memory cells
CD4 cells
Activated when antigen presented by antigen presenting cell (APC) cell
Develops into helper T-cells and memory cells
Helper T-cells must activate CD8 cells before they can become fully activated killer T’s

32. Cell Mediated Immunity continued
Killer T’s leave lymphatic tissue to search for and destroy virus infected cells, tumor cells and tissue transplant cells on contact

33. Cell Mediated Immunity Diagram

34. Question Which of the following activate Killer T-cells? B-cells
plasma cells
Helper T-cells
antibodies
none of the above

35. Antibody Mediated Immunity
Antigen causes production of antibodies
B-cell lymphocytes stay in lymph tissues
Antigen enters lymph tissue and binds to B-cell receptors
B-cells become activated
B-cells divide (clone) to form identical plasma cells and memory cells
Helper T-cells bind to antigen on compatible B-cells and “help” stimulate plasma cell and memory cell formation

36. Antibody Mediated Immunity
Plasma cells secrete various types of antibodies
Antibodies then bind to the specific antigen that activated its parent B-cells
Antibodies then cause the destruction of the antigen in several ways

37. Antibody Mediate Immunity Diagram

38. Question Which cells secrete most of the antibodies? Plasma cells
T-cells
B-cells
NK cells
none of the above

39. Antibody Mediated Immunity
Antibodies destroy antigens by
Neutralizing antigens such as toxins
Agglutinating (clumping) and precipitating (removing from solution) antigen bearing cells
Activating the complement proteins that destroy the antigen by various means
Enhancing phagocytosis by covering a microbe with antibodies

40. Antibody Mediated Immunity
There are five classes of antibodies
IgG, IgM, IgA, IgE and IgD
The IgG antibody is most common
Study Table 22-1, page 807 in text and earn some extra credit on exam by learning the functions for each type.
What does the Ig stand for?

41. Summary of Immunity

42. Immunological Memory
What is meant by the terms primary response and secondary response?
What causes the secondary response?

43. Question What does the Ig in the antibody symbol stand for?
Interferon globulin
Immunoglobin
Immunogenic
Immunoglobulin
none of the above

44. Disorders of the Immune System
To earn extra credit on your exam, study “Immune Disorders” on pages in your text.