4. Lecture of Role of Lymphocytes in Immunity.pptx

A lecture on Immunity for bachelor level students of medicine and related fields

1. Role of Lymphocytes in immunity

2. LEARNING OBJECTIVES Classify cells of immune system with respect to their origin Describe the basic types of Acquired immunity: Humoral Cell mediated Describe the role of lymphocytes in development of immunity.

3. Introduction Immune system is an internal defense system that plays a key role in recognizing and either destroying or neutralizing materials that are not “normal self” either foreign materials that have entered the body or abnormal cells that have arisen within the body:

4. The primary foreign enemies against which the immune system defends are bacteria and viruses.

5. Definition Immunity is the body’s ability to resist or eliminate potentially harmful foreign materials or abnormal cells

6. Types of Immunity Innate Immunity Adaptive or Acquired Immunity

7. Types of Immunity Innate Immunity Adaptive or Acquired Immunity

8. Cells of Immune System

9. Types of Immunity Innate Immunity Adaptive or Acquired Immunity

10. Innate immune system These innate immune system encompasses the body’s nonspecific immune responses that come into play immediately on exposure to a threatening agent . These responses are inherent (innate or built-in) defense mechanisms that non selectively defend against foreign or abnormal material and provide first line defense.

11. 1. Phagocytosis of bacteria and other invaders by white blood cells and cells of the tissue macrophage system.

12. Destruction of swallowed organisms by the acid secretions of the stomach and the digestive enzymes. 3. Resistance of the skin to invasion by organisms

13. Types of Immunity Innate Immunity Adaptive or Acquired Immunity

14. The Adaptive or acquired immunity relies on specific immune responses selectively targeted against a particular foreign material to which the body has already been exposed.

15. TYPES OF ACQUIRED IMMUNITY

16. Pre- Procesing of B & T Lymphocytes

17. Acquired immunity is caused by a special immune system that forms antibodies and/or activated lymphocytes that attack and destroy the specific invading organism or toxin

18. Humoral immunity develops by circulating antibodies which are globulin molecules in the blood plasma that are capable of attacking the invading agent. This type of immunity is called B-cell immunity because B lymphocytes produce the antibodies.

19. The primary immune response occurs when an antigen comes in contact to the immune system for the first time. During this time the immune system has to learn to recognize antigen and how to make antibody against it and eventually produce memory lymphocytes. The secondary immune response occurs when the second time (3rd, 4th, etc.) the person is exposed to the same antigen. At this point immunological memory has been established and the immune system can start making antibodies immediately.

20. The Cell mediated immunity is achieved through the formation of large numbers of activated T lymphocytes that are specifically crafted in the lymph nodes to destroy the foreign agent.

21. This type of immunity is called T-cell immunity (because the activated lymphocytes are T lymphocytes).

22. Because acquired immunity does not develop until after invasion by a foreign organism or toxin, it is clear that the body must have some mechanism for recognizing this invasion.

23. Each toxin or each type of organism almost always contains one or more specific chemical compounds in its makeup that are different from all other compounds.

24. These substances are called Antigens . An antigen is large foreign unique molecule that triggers a response against itself when it gains entry into body.

25. Defense Mechanisms External defense Internal Defense Immune Defense