Immunology-primary lymphoid Organs system

primary lymphoid organs structure and fuctional

1. V.Bhuvaneshwari II B.SC. Biotechnology PG & Research Department of Biotechnology Vivekanandha Arts and Science College For Women Sankari Assignment on “Primary lymphoid organs” Subject: Immune system and immuno technology PG & RESEARCH DEPARTMENT OF BIOTECHNOLOGY VIVEKANANDHA ARTS & SCIENCE COLLEGE FOR WOMEN [An ISO 9001:2015 Certified Institution] (Affiliated to Periyar University, Salem Recognised Under Section 2(f) &12(B) of the UGC Act, 1956) Veerachipalayam , Sankari West (Post) – 637 303, Sankari Tk , Salem Dt., Tamil Nadu

2. Primary lymphoid organs

3. conents What is lymphatic system Primary lymphoid organs Thymus Bone marrow

4. What is lymphatic system The lymphatic system is a network of vessels, nodes, and ducts that pass through almost all bodily tissues . It allows the circulation of a fluid called lymph through the body in a similar way to blood. It is part of the immune system. The lymphatic system is essential for fluid balance, absorption of fatty acids in the stomach, and immune system regulation.

5. Primary lymphoid organs The primary lymphoid organs, also referred to as central lymphoid/lymphatic organs, are the tissues responsible for the production of lymphoid cells from progenitor cells, incuding the  bone marrow  and the  thymus https://www.geeksforgeeks.org/lymphoid-organs /

6. thymus Definition : The thymus is a small, butterfly-shaped gland that plays a crucial role in the development and maturation of immune cells called T-lymphocytes (T cells) Role : 1 . T cell development and maturation 2. Immune system regulation 3. Central tolerance (elimination of self-reactive T cells) 4. Peripheral tolerance (education of T cells to be tolerant of self-antigens)

7. Process : T cell precursors enter the thymus Positive selection (T cells recognize self-MHC) Negative selection (elimination of self-reactive T cells) Maturation (T cells become functional CD4+ or CD8+ cells) Export (mature T cells leave the thymus)6. Peripheral tolerance (T cells educated to be tolerant of self-antigens) Location:- In the chest, behind the sternum (breastbone) - In front of the trachea (windpipe)- Above the heart Below the thyroid gland - In the mediastinum (anterior chest cavity)

8. Size :- Typically 4-5 cm (1.5-2 inches) long 2-3 cm (0.8-1.2 inches) thick wide- 1-2 cm (0.4-0.8 inches) Weight: around 10-15 grams (0.4-0.5 ounces) https:// www.researchgate.net/figure/b-Diagrammatic-cross-section-of-a-portion-of-the-thymus-showing-several-lobules_fig23_325019907

9. Bone marrow Definition : Bone marrow is the spongy tissue inside bones that produces blood cells, including red blood cells, white blood cells, and platelets Role of bone marrow Hematopoiesis : Produces blood cells from stem cells Erythropoiesis : Produces red blood cells Leukopoiesis : Produces white blood cells Thrombopoiesis : Produces platelets Storage: Stores stem cells, platelets, and red blood cells Filtering : Filters the blood to remove old or damaged cells

10. Process Stem cell differentiation: Stem cells develop into specific blood cell types Cell maturation : Immature cells mature into functional blood cells Cell release : Mature cells enter the bloodstreamLocation Location Inside the cavities of bones, particularly: Pelvis Vertebrae Ribs Femur (thigh bone) Found in both children and adults, but more active in children

11. Size :- Varies depending on age and bone size Approximately 4% of adult body weight (around 2.5-3 kg or 5.5-6.6 lbs) - More extensive in children, gradually decreasing with age https:// microbenotes.com/bone-marrow-types-structure-and-functions /

12. Murphy, K., & Weaver, C. (2016). Janeway's immunobiology (9th ed.). Garland Science. Parham, P. (2020). The immune system (5th ed.). Cengage Learning. Owen, J., Punt, J., & Stranford , S. (2013). Kuby immunology (7th ed.). W.H. Freeman. Roitt , I., & Male, H. (2016). Immunology (9th ed.). Elsevier. Abbas , A. K., Lichtman , A. H., & Pillai , S. (2021). Cellular and molecular immunology (10th ed.). Elsevier. Reference Books

13. Thank you V.Bhuvaneshwari