Cells of the Immune System PDF

CELLS OF THE IMMUNE SYSTEM – DR. HUSSEIN (2ND PPT) 1. What is hematopoiesis? A: The process of blood cell maturation from a stem cell to a functional blood cell (red or white). 2. What are the primary tissues of the immune system? A: Bone marrow and thymus. 3. What cells are derived from the lym...

CELLS OF THE IMMUNE SYSTEM – DR. HUSSEIN (2ND PPT) 1. What is hematopoiesis? A: The process of blood cell maturation from a stem cell to a functional blood cell (red or white). 2. What are the primary tissues of the immune system? A: Bone marrow and thymus. 3. What cells are derived from the lymphoid lineage? A: T cells, B cells, and Natural Killer (NK) cells. 4. What are the components of the myeloid lineage? A: Polymorphonuclear granulocytes (Neutrophil, Basophil, Eosinophil), Monocytes (Macrophages), and Dendritic cells. 5. What is the role of T helper cells (TH)? A: To activate and direct other immune cells by releasing cytokines. 6. What do cytotoxic T cells (Tc or CTL) do? A: They destroy virus-infected cells and cancer cells. 7. What type of immune cells are B cells? A: B cells are responsible for producing antibodies. 8. What is the function of Natural Killer (NK) cells? A: To destroy infected or cancerous cells without prior sensitization. 9. What cells are involved in the process of extravasation (diapedesis)? A: Polymorphonuclear granulocytes (neutrophils) leave the circulation to fight infection. 10. What cytokine is involved in memory T cell and monocyte chemoattraction? A: RANTES (Regulated on activation, normal T-cell expressed and secreted). 11. What are the primary granules of neutrophils? A: Hydrolases, Peroxidases, and Lysozyme. 12. What do secondary granules in neutrophils contain? A: Lactoferrin and Lysozyme. 13. What is the main function of neutrophils? A: Phagocytosis of pathogens and promoting inflammation. 14. How do neutrophils kill pathogens? A: By producing reactive oxygen metabolites, hydrolytic enzymes, nitric oxide, and antibiotic proteins like defensins. 15. What is the function of basophils and mast cells? A: To release mediators of immediate hypersensitivity, such as histamine and heparin. 16. What do eosinophils release to kill parasites? A: Basic proteins and cationic proteins. 17. Where are macrophages found in the body? A: They are found in various organs, such as the liver (Kupffer cells), brain (microglial cells), and skin (Langerhans' cells). 18. What percentage of white blood cells are neutrophils? A: 50-60%. 19. What is the role of monocytes when they migrate into tissues? A: They differentiate into macrophages and play a role in phagocytosis. 20. What are dendritic cells known for? A: Antigen presentation to T cells in lymph nodes and the spleen. 21. What are the major functions of platelets? A: Blood clotting and inflammation. 22. What is the primary role of T cells? A: They are involved in cellular immunity, specifically by helping or killing infected cells. 23. What cells serve as antigen-presenting cells (APCs)? A: Macrophages, dendritic cells, and B cells. 24. What are the primary lymphoid organs? A: Bone marrow and thymus. 25. Where do B cells develop? A: In the bone marrow. 26. What is the main site of T cell development? A: Thymus. 27. What is DiGeorge syndrome? A: A congenital condition where the thymus is absent, leading to a drastic reduction in T cells. 28. What are secondary lymphoid organs? A: Spleen, lymph nodes, and mucosa-associated lymphoid tissue (MALT). 29. What is the function of the spleen in the immune system? A: It traps and concentrates foreign substances and produces antibodies and T cells. 30. What is mucosa-associated lymphoid tissue (MALT)? A: Lymphoid tissue scattered along mucosal linings, providing immune defense. 31. What are Peyer's patches? A: Lymphoid tissue found in the small intestine that plays a role in immune response. 32. What is the role of M cells in MALT? A: To absorb, transport, and present antigens to subepithelial lymphocytes. 33. What are Langerhans' cells? A: Dendritic cells found in the skin that serve as antigen-presenting cells. 34. What type of immunity are Natural Killer (NK) cells involved in? A: Innate immunity. 35. What immune function does the thymus provide in early life? A: It helps T cells learn to differentiate between self and non-self antigens. 36. What is the significance of MHC-I and MHC-II on immune cells? A: They help in antigen presentation for immune response activation. 37. What types of immune responses do macrophages initiate? A: Phagocytosis and antigen presentation to helper T cells. 38. What is the main role of plasma cells? A: To produce antibodies. 39. What are the chemical mediators released by mast cells and basophils? A: Histamine, heparin, prostaglandins, and leukotrienes. 40. What immune cells play a major role in fighting parasitic infections? A: Eosinophils.