1. The Lymphatic System and Immune Response
Exercise 38
The Lymphatic System and Immune Response

2. Lymphatic System Lymphatic vessels Lymphatic tissues Tonsils
Primary lymphatic organs
Thymus and Bone marrow
Secondary lymphatic organs
Lymph nodes, spleen

3. Lymphatic System

4. Lymphatic System Lymph Fluid lost from the capillaries Edema
Functions of the lymphatic system:
Transport lymph to the blood vessels
Protects the body

5. Lymphatic vessels Lymphatic capillaries Lymphatic collecting vessels
Lymphatic trunk
Right lymphatic duct - drains lymph from:
Head right upper extremity
Right thorax
Drains into right subclavian vein

6. Lymphatic vessels Thoracic duct – drains lymph from: Rest of the body
Drains into left subclavian vein
Cisterna chyli
Characteristic of the lymphatic vessels
Walls with 3 tunics
Presence of valves
Presence of abundant anastomoses

7. Lymphatic vessels

8. Primary lymphoid organs
Bone marrow
Contain the stem cell that will give rise to all lymphocytes
Site of B cell differentiation or immunocompetency
Thymus
Site of T cell differentiation or immunocompetency

9. Thymus

10. Secondary lymphatic organs
Lymph nodes
Bean-shaped
Numerous
Regional lymph nodes:
Cervical
Axillary
Inguinal, etc
Hilus
Afferent and efferent vessels

11. Secondary lymphatic organs
Microscopy
Capsule and subcapsular sinus
Trabecula
Cortex
Outer cortex (follicles)
Germinal center containing dividing B cells
Deep cortex or paracortical area
Contain T cells

12. Secondary lymphatic organs
Medulla
Medullary cords
Medullary sinuses
Contain macrophages and plasma cells

13. Secondary lymphatic organs
Spleen
Capsule
White pulp
Central artery
Lymphocytes
Red pulp
Venous sinuses
Reticular tissue
Macrophages arranged I splenic cords

14. Spleen

15. Lymphoid tissues Tonsils One pharingeal Two palatines Two linguals
Presence of germinal center
Presence of crypts

16. Tonsils

17. The immune response It is a systemic response
Destroys or neutralizes foreign substances
Characteristics of immune responses
Memory
Immunocompetent lymphocytes are monospecific
Specificity
Ability to differentiate self from nonself

18. The immune response Antigens Foreign proteins Polysaccharides Haptens
Lymphocytes
Responsible for the immune response
Autoimmunity

19. Organ, cells and cell interaction of the immune response
Hemocytoblasts in the bone marrow give rise to lymphocytes
Types of Lymphocytes:
B - will stay in the bone marrow for maturation (immunocompetence)
T - will migrate to thymus for maturation (immunocompetence)
Natural Killers

20. Organ, cells and cell interaction of the immune response
B and T cell will then leave bone marrow and thymus, enter the blood stream and travel to secondary lymphatic organs
Site for clonal selection

21. Organ, cells and cell interaction of the immune response
B and T cell will bind to specific antigens and then undergo clonal multiplication
B cell may become
Memory
Plasma cell
Humoral immunity

22. Organ, cells and cell interaction of the immune response
T cell may become
Memory
Cytotoxic
Helper
Suppressor
Cellular immunity

23. Antibodies and tests for their presence
Characteristics of antibodies or Immunoglobulins (Igs)
Produced only by plasma cells
They are plasma proteins (gamaglobulins)
Found in all body secretions

24. Antibodies and tests for their presence
Classes of antibodies
IgM, IgG, IgA, IgD, IgE
Structure of the immunoglobulins
2 heavy chains
2 light chains

25. Antibody