Lymphatic system ppt
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The lymphatic system consists of lymph vessels, lymph nodes, and lymph that work together to transport fluid and defend the body against disease. Lymph is a fluid containing white blood cells that flows through lymph vessels and lymph nodes, where the nodes filter out pathogens and foreign materials. The lymph eventually drains into the bloodstream via two main ducts. Disorders can occur if the lymphatic system becomes blocked or infected, impairing its ability to circulate lymph and mount an immune response.
Lymphatic system ppt
- 1. LYMPHATIC SYSTEM Presented by: Mr.Vijayreddy Vandali M.Sc(N),PGDHA,PGCDE. ASSOCIATE PROF CUM VICE-PRINCIPAL SCHOOL OF NURSING, P P SAVANI UNIVERSITY, SURAT, GUJARAT, INDIA.
- 2. IMPORTANT TERMS • Lymph - a fluid that contains white blood cells that defend against germs • Lymph vessels - vessels that carry lymph throughout your body. They are different from blood vessels. • Lymph nodes - glands found throughout the lymph vessels. Along with your spleen, these nodes are where white blood cells fight infection.
- 3. LYMPHATIC SYSTEM • Protects body against foreign material • Assists in circulation of body fluids between cells and bloodstream • Transports dietary fats
- 4. LYMPHATIC SYSTEM (cont.)• Consists of: - Lymph - Network of vessels - Lymph nodes and nodules - Tonsils - Spleen - Thymus gland - Bone marrow
- 7. LYMPH (lymph = clear fluid) • Derived from tissue fluid • Contains more white blood cells than plasma • Enters node through afferent lymphatic vessels • Flows through node in one direction
- 10. LYMPH (CONT.) • flows through sinuses in lymph node cortex and then into the medulla • exits the lymph node through efferent lymphatic vessels • must be returned to blood stream to maintain blood volume and pressure
- 13. LYMPH CAPILLARIES • Microscopic closed-ended vessels • Located next to blood capillaries in tissue spaces • Larger diameter than blood capillaries • Are very permeable and collect tissue fluid and proteins • Lymph capillaries merge to form larger lymph vessels
- 14. LYMPH VESSELS • Resemble veins but have thinner walls and more valves • Ends of endothelial cells overlap - Act as one-way valves allowing interstitial fluid to flow in but not out • Attached to surrounding tissue by anchoring filaments
- 16. LYMPH VESSELS (cont.) • No pump for lymph • Lymph is kept moving by: - Constriction of vessels - Skeletal muscle pump - Respiratory pump • At intervals along vessels lymph flows into lymph nodes • Lymphatic vessels unite to form lymph trunks
- 17. LYMPH TRUNKS • formed by lymphatic vessels uniting • large tubes • empty their lymph into lymphatic ducts
- 18. LYMPHATIC DUCTS • Lymph empties into two conducting ducts: - the thoracic duct (left lymphatic duct) - the right lymphatic duct Lymph from these ducts enters the blood stream via the left subclavian vein and the right subclavian vein
- 20. Thoracic Duct (left lymphatic duct) • about 15-18 inches (38-45 cm) in length • begins as a dilation called the cisterna chyli • main collecting duct of lymphatic system • receives lymph from lower body and upper left quadrant • empties into the left subclavian vein
- 21. CISTERNA CHYLI • large lymph vessel • formed by the union of lymph vessels from lower body • located anterior to the second lumbar vertebra • continues superiorly as thoracic duct
- 22. RIGHT LYMPHATIC DUCT • about 0.5 inches (1.5 cm) in length • receives lymph from upper right quadrant • empties into the right subclavian vein
- 23. LYMPH NODES • oval or bean-shaped • masses of lymphatic tissue • aid in defense and white blood cell formation • located along length of lymphatic vessels • scattered throughout the body usually in clusters
- 26. LYMPH NODES (cont.) • covered by a capsule • contain capsular extensions called trabeculae (form partitions within node) • internal to capsule are reticular fibers and fibroblasts - form framework of a lymph node • Two main regions of a lymph node: - cortex - medulla
- 27. CORTEX • outer region directly beneath the capsule • contains densely packed lymphocytes arranged in masses called follicles - outer rim of follicle contains T cells, macrophages, and follicular dendritic cells (aid in T cell activation)
- 28. MEDULLA • inner region • lymphocytes are arranged in strands called medullary cords - contain macrophages and plasma cells
- 29. BIOLOGICAL FILTRATION • as lymph passes through a node bacteria and other foreign materials are trapped by reticular fibers within the node - bacteria are then phagocytized by macrophages
- 30. BIOLOGICAL FILTRATION (cont.) • plasma cells produce antibodies to antigens in the lymph • antibodies, lymphocytes, and monocytes are eventually returned to the blood via subclavian veins
- 31. MAJOR LYMPH NODES • cervical • axillary • inguinal • mesenteric
- 33. CERVICAL • located in neck area • filter lymph from head and neck
- 34. AXILLARY • located in armpits • filter lymph from hand, arm, breast
- 35. INGUINAL • located in groin area • filter lymph from lower extremities and external genital organs
- 36. MESENTERIC • located in abdominal peritoneum • aid in infection control after abdominal surgery • filter lymph from abdominal cavity
- 37. METASTASIS • process by which bacteria or body cells are spread from one body part to another through lymphatic or circulatory systems • cancer cells migrate to nearby nodes, eg. breast cancer to axillary nodes - chemotherapy is necessary once metastasis occurs
- 38. DIFFUSE LYMPHATIC TISSUE • not enclosed by a capsule • consists of reticular connective tissue that contains lymphatic nodules • Found in: - small amounts in almost every organ, especially mucous membranes that line tracts of body
- 39. ISOLATED LYMPHATIC NODULES (B CELLS) • oval-shaped concentrations of lymphatic tissue • most are solitary, small, and discrete • Scattered in lamina propria of mucous membranes of: - gastrointestinal tract - respiratory airways - urinary and reproductive tract
- 40. ISOLATED LYMPHATIC NODULES (B CELLS) (cont.) • when activated by antigens they differentiate into plasma cells and produce antibodies against specific antigens • plasma cells secrete IgA antibodies - provide protection against bacterial and viral infections in lumen of tracts
- 41. ISOLATED LYMPHATIC NODULES (B CELLS) (cont.) • located in mucus membranes of gastrointestinal tract • Examples: - tonsils - ileum of small intestine (Peyer’s patches) - appendix
- 42. TONSILS • Aggregations of large lymphatic nodules • Embedded in mucous membrane • Located beneath epithelium of pharynx and oral cavities • Protect nasal and oral cavities • Three types: - Nasopharyngeal tonsils - Palatine tonsils - Lingual tonsils
- 44. NASOPHARYNGEAL TONSILS • Commonly called adenoids • Located: - Behind nose - On roof of posterior wall of pharynx - Posterior opening of nasal cavity
- 45. PALATINE TONSILS • Usually referred to as the “tonsils” • Location: - Back of mouth - Lateral walls of pharynx • Most commonly removed - tonsillectomy
- 46. LINGUAL TONSILS • Base of tongue • First line of defense from exterior
- 47. SPLEEN • Largest lymphatic organ • Located in upper left abdominal quadrant • Between fundus of stomach and diaphragm • 5-6 inches long, 2-3 inches wide • Resembles a large lymph node • Filters blood
- 49. STRUCTURE OF SPLEEN • Capsule - covering of dense connective tissue • Hilum - depression on medial surface - nerves and arteries enter spleen, veins and lymphatic vessel exit
- 50. STRUCTURE OF SPLEEN (cont.) • Trabeculae - extensions of capsule, form partitions within the spleen • Pulp - tissue inside - divided into red and white
- 51. WHITE PULP • consists of lymphatic tissue • mostly lymphocytes arranged around central arteries
- 52. RED PULP • Consists of: - venous sinuses filled with blood - cords of splenic tissue consists of red blood cells, macrophages, lymphocytes, plasma cells, and granulocytes
- 53. FUNCTIONS OF SPLEEN • Phagocytosis of bacteria and worn out or damaged red blood cells and platelets • Stores and releases blood in times of demand, e.g., hemorrhage • Functions in immunity as a site of B cell proliferation into plasma cells • Does not filter lymph because it has no afferent lymphatic vessels or lymph sinuses
- 55. THYMUS GLAND • two-lobed organ • located in upper part of chest along trachea • inferior to thyroid gland, posterior to sternum • largest and most active during prenatal period and infancy • after puberty it decreases in size
- 57. THYMUS GLAND (cont.) • composed of lymphatic tissue • subdivided into lobules • immature T cells originating in the bone marrow migrate to thymus via blood • in thymus, cells develop into mature T cells for release into circulation • thymic hormones aid in maturation of T cells
- 58. THYMUS GLAND (cont.) • mature T cells travel to lymph nodes, spleen, and diffuse lymphatic tissues where they reside • responsible for cell-mediated immune responses
- 59. REMOVAL OF THYMUS (THYMECTOMY) • can be removed but decreased T-cell production results • possible acute susceptibility to infection
- 60. REMOVAL OF SPLEEN (SPLENECTOMY) • can be removed • other organs, e.g. the liver and bone marrow can compensate for it • increased susceptibility to disease may result
- 61. DISORDERS OF LYMPHATIC SYSTEM • The lymphatic system may not carry out its function adequately due to • Blockage (obstruction): Obstruction in the lymphatic system leads to an accumulation of fluid ( lymphedema). Obstruction may result from scar tissue that develops when the lymph vessels or nodes are damaged or removed during surgery, by radiation therapy, by injury, or in tropical countries, by infection with a threadworm (filariasis) that blocks the lymphatic ducts.
- 65. CONTD.. • Infection: Infection may cause swollen lymph nodes because the lymph nodes are inflamed. Sometimes the lymph nodes themselves may become infected ( lymphadenitis) by organisms that spread through the lymphatic system from the original site of infection.
- 68. CONTD… • Cancer: Tumors may block the lymphatic ducts or may travel (metastasize) to lymph nodes near a tumor, interfering with flow of lymphatic fluid through the node. Rarely, a tumor (lymphangiosarcoma) may develop in the lymphatic system.
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