Immunity
Download as PPT, PDF77 likes5,089 views
This document provides an overview of the immune system, including its three levels of defense (innate, inflammatory, adaptive) and the key cells involved. It discusses the roles of monocytes, neutrophils, eosinophils, basophils, T cells (helper, killer, memory), and B cells. The innate system's physical and chemical barriers are described, as well as the inflammatory response. The adaptive system is mediated by lymphocytes that recognize, destroy, and remember pathogens.
Immunity
- 1. Life Saving College Of Nursing By: Farooq Marwat
- 2. Objectives At the end of this presentation, students will Know about different level of immunity The Mechanism of immunity Know about inflammatory response Know about different Cells of immune system Know about Proteins that helps in immunity
- 4. Levels of Immune System When a pathogen or any antigen try to enter into the body, it is resist with different mechanism at different levels and of immunity Basically there are three Levels of immunity which encounter the pathogen
- 5. First Line Defense/Innate immunity The body's first line of defense against pathogens uses mostly physical and chemical barriers. Such barrier includes: Skin – acts as a barrier to invasion Sweat – has chemicals which can kill different pathogens.
- 6. First Line Defense/Innate immunity Tears - have lysozyme which has powerful digestive abilities that render antigens harmless. Saliva – also has lysozyme. Mucus - can trap pathogens, which are then sneezed, coughed, washed away, or destroyed by chemicals. Stomach Acid – destroys pathogens
- 7. Second-Line Defenses If a pathogen is able to get past the body's first line of defense, and an infection starts, the body can rely on it's second line of defense. This will result in a process is called Inflammatory response (inflammation )
- 8. Inflammatory Response Inflammatory response is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process. It is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants.
- 9. Inflammatory response Inflammatory response causes Redness - due to capillary dilation resulting in increased blood flow Heat - due to capillary dilation resulting in increased blood flow Swelling – due to passage of plasma from the blood stream into the damaged tissue Pain – due mainly to tissue destruction and, to a lesser extent, swelling.
- 11. Third-Line Defenses Sometimes the second line of defense is still not enough and the pathogen is then heading for the body's last line of defense, the immune system. The immune system recognizes, attacks, destroys, and remembers each pathogen that enters the body. It does this by making specialized cells and antibodies that render the pathogens harmless.
- 12. Third-Line Defenses Unlike the first line and second line defense the immune system differentiates among pathogens. For each type of pathogen, the immune system produces cells that are specific for that particular pathogen therefore also called Specific Immunity.
- 15. Cells of Immune System White Blood Cells Phagocytes Neutrophils Monocytes / Macrophages Eosinophils Basophils Lymphocytes
- 16. Monocytes/Macrophages The monocytes are larger WBCs about 10 to 18 um in diameter (enlarge 5 to 10 times more when encounter with pathogen) They represent 5-8% of WBCs Monocytes have a horse shoe shape nucleus and contain azurophilic granules and have got well developed Golgi complexes and lysosomes.
- 17. Monocytes/Macrophages Phagocytic macrophages are present in many organs and are named according to there position e.g. liver macrophages are also called Kuffer cells & brain cells are also called Macroglial cells. They are long lived months to years Monocytes / Macrophages actively phagocytise organisms There main role is to remove the antigens from the body
- 18. Monocytes
- 19. Neutrophils The most numerous cells of Immune system are the neutrophils also called PMNs (Polymorphs), constitute the majority of leukocytes in the blood i.e. about 60 – 70 % They have characteristic multi lobed nucleus and are 10 – 20 um in diameter. Large numbers are released during infections Short lived – die after digesting bacteria
- 20. Neutrophils Like monocytes they adhere to endothelial cell lining of the blood vessels and move toward tissues by squeezing between the endothelial cells to leave the circulation. This process is known as diapedesis. This process is promoted by chemo attractants such as chemokines. They are Patrol tissues as they squeeze out of the capillaries. Dead neutrophils make up a large proportion of puss. There main role is phagocytosis .
- 21. Eosinophils Eosinophils comprise 2 – 5 % of the blood leukocytes in a healthy non allergic person Eosinophils have a bi lobed nucleus with many cytoplasmic granules that stain with acidic dye e.g. eosin There are many hydrolytic enzymes present in the granules responsible for the anti- helminthic activity.
- 22. Eosinophils Eosinophils also release histaminase and aryl sulphatase which inactivate the mast call products e.g histamine. The effect of eosinophils thus dampen down the effect of inflammatory response. This type of action these cells can only make and only against large pathogens which cannot be phagocytosed e.g parasitic worms
- 24. Basophils Basophils are found in a small number in the circulation, about less than 0.2 % of leukocytes Basophils have membrane bounded granules. These granules in both basophils or mast cells contain Heparin Leukoterins histamine etc. The stimulus for these cells is an allergen – an antigen causing allergic reaction.
- 25. Basophils
- 26. Lymphocytes
- 27. Lymphocytes Responsible for the specific immune response. They are agranulocytes Represent 20-40% of circulating WBC in blood Further sub divided into T lymphocytes and B lymphocytes Once stimulated with antigen enlarges 15µm into a blast cell.
- 28. T Lymphocytes These cells are mature In thymus gland therefore called T- lymphocytes. T-cells play major role in cell immediate immunity. T-cells further divided in Killer T-cells Helper T-cells Memory T-cells
- 29. Killer T Cells Killer T Cells recognize surface markers on other cells labeled for destruction. Killer T Cells help to keep virus-infected or malignant cells in check.
- 30. Killer T cell in action
- 31. Helper T cells Helper T cells are the sub group of T Lymphocytes. These cells have no cytotoxic or phagocytic activity. Helper T cells activate and direct other immune cells and helps in maximizing bactericidal activity of phagocytes
- 32. Memory T-cells Memory T-cells are derived from normal T-cells Memory T cells have learned how to overcome an invader by ‘remembering’ the strategy used to defeat previous infections. The memory cells are long-lived cells
- 33. B Lymphocytes These cells are mature in bone marrow then circulate in blood and lymph. They produce antibodies against antigen, play major role in Humeral immunity There are more than 10 million different B- lymphocytes, each of which make a different antibody. The B- cells which produce antibodies are called plasma cells.