Lymphatic System.pptx

this content will be beneficial for b.sc. nursing students.

1. LYMPHATIC SYSTEM

2. IMPORTANT TERMS Lymph - a fluid that contains white blood c e l l s t ha t d e f e n d a g ains t g e r ms 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 P r o te ct s b o d y a g ain s t f o rei g n m at e r i a l A s s i s t s i n c i r c u l at i o n o f b o dy between cells f l u i ds a n d b l oo d s t ream T r a n s p o r t s d i e ta r y fats

4. LYMPHATIC SYSTEM (c on t . ) Consists of: - L ym p h Network of vessels L ym p h n o des a n d n o du l e s Tonsils Spleen T h y m u s g l a n d B o n e m a r r o w

5. L Y M PH (lymph = clear fluid) D e r i v e d f r o m t is s u e f l u i d C o n t a i n s m o r e w h ite b lo o d c el l s t h a n p la s ma E n ters n o d e t h r o u g h a ff ere n t l y m p h a ti c v e ss e ls F l o w s t h r o u g h n o de in o n e di r e c t i o n

6. L Y M P H ( C O N T . ) flows through sinuses in lymph node cortex and then in t o t h e medu l la exits the lymph node through efferent lymphatic vessels must be returned to blood stream to maintain blood v o l u m e a n d p re s s u re

7. LYMPH CAPILLARIES Microscopic closed-ended vessels L o c a t e d n e x t t o b l o o d c a p i ll a r i es i n t i ssu e s p a c es L a r g e r d i a m e t e r t h a n b l o o d c a p i ll a r i es A r e v e r y p e r m e a b l e a n d c o l l e c t t i s su e f l u i d a n d proteins Ly m p h c a p i ll a r i es m e r g e t o f o r m l a r g e r l y m p h vessels

8. 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 f l ow in b u t n o t o u t Attached to surrounding tissue by anchoring filaments

9. LYMPH VESSELS (cont.) N o p u m p f o r ly m p h Lymph is kept moving by: Constriction of vessels S k e let a l m u s cl e p u m p R e s p ira t o r y p u mp At intervals along vessels lymph flows into lymph nodes Lymphatic vessels unite to form lymph trunks

10. LYMPH TRUNKS f o r me d b y lym p h a t ic v e ss e l s u n i t in g la r g e tu b e s e m p t y t h ei r l y m ph i n t o l y m ph a t i c du c t s

11. LYMPHATIC DUCTS Lymph empties into two conducting ducts: t h e t h o r ac i c du c t ( l e f t ly m p h a ti c d u c t ) t h e r i gh t l y m ph a t i c du c t L ym p h f r o m t h e se d u c t s e n t er s t h e b lo o d s tre a m v i a the left subclavian vein and the right subclavian vein

12. 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

13. CIS T ER NA C H Y LI 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

14. RIGHT LYMPHATIC DUCT ab out 0.5 inches (1.5 cm) in length receives lymph from upper right quadrant empties into the right subclavian vein

15. 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

16. LYMPH NODES (cont.) co vered 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 T w o m a i n r e g i o n s o f a l y m p h n o d e : cortex medulla

17. C O R T E X 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)

18. MEDULLA inner region lymphocytes are arranged in strands called medullary cords - contain macrophages and plasma cells

19. 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

20. 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

21. MAJOR LYMPH NODES cervical axillary inguinal m e s e n t e r ic

22. CERVICAL located in neck area filter lymph from head and neck

23. A X I L LA R Y located in armpits filter lymph from hand, arm, breast

24. I N G U I N AL located in groin area filter lymph from lower extremities and external genital organs

25. MESEN T ERIC located in abdominal peritoneum aid in infection control after abdominal surgery filter lymph from abdominal cavity

26. M E T AS T AS I S 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

27. DIFFUSE LYMPHATIC TISSUE not enclosed by a capsule consists of reticular connective tissue that contains lymphatic nodules F o u n d i n : - small amounts in almost every organ, especially mucous membranes that line tracts of body

28. ISOLATED LYMPHATIC NODULES (B CELLS) oval-shaped concentrations of lymphatic tissue most are solitary, small, and discrete S c a t t e r e d i n l a m i n a p r o p r i a o f m u c o u s m e m b r a n e s o f : gastrointestinal tract respiratory airways urinary and reproductive tract

29. 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

30. ISOLATED LYMPHATIC NODULES (B CELLS) (cont.) located in mucus membranes of gastrointestinal tract Examples: tonsils ileum of small intestine (Peyer’s patches) appendix

31. TONSILS Aggregations of large lymphatic nodules Embedded in mucous membrane Located beneath epithelium of pharynx and oral cavities Protect nasal and oral cavities T h r ee t y p e s : Nasopharyngeal tonsils Palatine tonsils Lingual tonsils

32. NASOPHARYNGEAL TONSILS Commonly called adenoids Located: Behind nose On roof of posterior wall of pharynx Posterior opening of nasal cavity

33. PALATINE TONSILS Usually referred to as the “tonsils” Location: Back of mouth Lateral walls of pharynx Most commonly removed - tonsillectomy

34. L I N G U A L T ON S I LS Base of tongue First line of defense from exterior

35. 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

36. STRUCTURE OF SPLEEN Capsule covering of dense connective tissue Hilum depression on medial surface nerves and arteries enter spleen, veins and lymphatic vessel exit

37. STRUCTURE OF SPLEEN (cont.) Trabeculae extensions of capsule, form partitions within the spleen Pulp tissue inside divided into red and white

38. WHITE PULP consists of lymphatic tissue mostly lymphocytes arranged around central arteries

39. RED PULP C o n s i s t s o f : venous sinuses filled with blood cords of splenic tissue consists of red blood cells, macrophages, lymphocytes, plasma cells, and granulocytes

40. 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

41. 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

42. THYMUS GLAND ( c on t .) 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

43. THYMUS GLAND ( c on t .) mature T cells travel to lymph nodes, spleen, and diffuse lymphatic tissues where they reside responsible for cell-mediated immune responses

44. REMOVAL OF THYMUS (THYMECTOMY) can be removed but decreased T-cell production results possible acute susceptibility to infection

45. 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

46. 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.

47. CO NT D . . Infection: Infection may s w o l l e n l y mp h nod e s be c a u s e t he cause l y mph 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.

48. Granulomatous lymphadenitis

49. CO NT D … 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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