Lymphatic system, Human Lymphatic system

Tissue fluid (interstitial fluid) that enters the lymphatic vessels.
larger particles that escape into tissue fluid can only be removed via lymphatic system.

1. Lymphatic System Prep: Amen Ullah Lecturer Surgical 12/26/2018 1 [email protected]

2. What is lymph ? Tissue fluid (interstitial fluid) that enters the lymphatic vessels. larger particles that escape into tissue fluid can only be removed via lymphatic system. 12/26/2018 2 [email protected]

3. Formation & Transport of lymph 12/26/2018 3 [email protected]

4. Lymphatic system It is a one-way system and allows the lymph flow from tissue spaces toward the blood. 12/26/2018 4 [email protected]

5. Lymphatic system 12/26/2018 5 [email protected]

6. ORGANIZATION OF LYMPHATIC SYSTEM Lymphatic system arises from tissue ------called lymph capillaries. Lymph capillaries has blind-ended terminals called capillary bulbs. These bulbs contain valves. M uscle fibers around these bulbs cause contraction of bulbs ----- so pushed through the vessels. Lymph capillaries are lined by endothelial cells. Capillaries unite to form large lymphatic vessels. Lymphatic vessels form the lymphatic ducts. The structure of lymph capillaries is slightly different from that of the blood capillaries. 12/26/2018 6 [email protected]

7. Lymphatic Vessels Collects lymph from lymph capillaries Delivers lymph to lymph nodes Returns fluid to circulatory veins near the heart Right lymphatic duct Thoracic duct About 120 mL of lymph flows into blood per hour 12/26/2018 7 [email protected]

8. SITUATION OF LYMPH VESSELS 1. Deeper layers of skin 2. Subcutaneous tissues 3. Diaphragm 4. Wall of abdominal cavity 5. Omentum 6. Linings of respiratory tract except alveoli 7. Linings of digestive tract 8. Linings of urinary tract 9. Linings of genital tract 10. Liver 11. Heart. 12/26/2018 8 [email protected]

9. Lymph vessels are not present in the following structures 1. Superficial layers of skin 2. Central nervous system 3. Cornea 4. Bones 5. Alveoli of lungs 12/26/2018 9 [email protected]

10. Composition of Lymph fluid 12/26/2018 10 [email protected]

11. LYMPH NODES Lymph nodes are small glandular structures located in the course of lymph vessels. The lymph nodes are also called lymph glands or lymphatic nodes 12/26/2018 11 [email protected]

12. STRUCTUTRE OF LYMPH NODES The structures are arranged in three layers namely Cortex paracortex medulla 12/26/2018 12 [email protected]

13. Lymph Node Lymph node receives lymph by one or two lymphatic vessels called afferent vessels. It circulates through cortex, paracortex and medulla of the lymph node. From medulla, the lymph leaves the node via one or two efferent vessels. 12/26/2018 13 [email protected]

14. Lymphatic Capillaries – Lacteals The small intestine contains special types of lymphatic capillaries called lacteals . Lacteals pick up not only interstitial fluid, but also dietary lipids and lipid-soluble vitamins. The lymph of this area has a milky color due to the lipid and is also called chyle . 12/26/2018 14 [email protected]

15. FUNCTIONS OF LYMPH NODES Filter lymph before it is returned to the blood Defense cells in nodes: Medulla houses macrophages which engulf and destroy foreign substances Cortex nurtures lymphocytes which provide immune response to antigens (cortex) 12/26/2018 15 [email protected]

16. Swelling Of Lymph Nodes During infection or any other processes in a particular region of the body, activities of the lymph nodes in that region increase. This causes swelling of the lymph nodes. Sometimes , the swollen lymph nodes cause pain. Most common cause of swollen lymph nodes is infection. Lymph nodes situated near an infected area swell immediately. When the body recovers from infection , the lymph nodes restore their original size gradually , in one or two weeks. 12/26/2018 16 [email protected]

17. Functions of Lymph Lymphatic capillaries absorb excess tissue fluid and return it to the bloodstream It is responsible for redistribution of fluid in the body . I n the small intestines, lymphatic capillaries called lacteals absorb fats in the form of lipoproteins and transport them to the bloodstream. Bacteria, toxins and other foreign bodies are removed from tissues via lymph. Lymph flow is responsible for the maintenance of structural and functional integrity of tissue. Obstruction to lymph flow affects various tissues, particularly myocardium, nephrons and hepatic cells. Lymph flow serves as an important route for intestinal fat absorption. This is why lymph appears milky after a fatty meal. T he lymphatic system is responsible for the production, maintenance , and distribution of lymphocytes. T he lymphatic system helps defend the body against pathogens 12/26/2018 17 [email protected]

18. Some Lymphatic system Pathologies LYMPHANGITIS Inflammation of the lymph vessels Commonest cause bacteria called streptococcus pyogenes ( most common ). Lymph vessels appear as red streaks through the skin. 12/26/2018 18 [email protected]

19. FILARIASIS LYMPHEDEMA 12/26/2018 19 [email protected]

20. LYMPHADENOPATHY Means a disease of the lymph nodes Lymph nodes become swollen/ enlarged and may be painful to touch 12/26/2018 20 [email protected]

21. LYMPHOMAS Cancers originating either from the lymphocytes in the lymph nodes or the lymphatic tissue in organs HIV & hepatitis may be a risk factor 12/26/2018 21 [email protected]

22. Thank You For attension 12/26/2018 22 [email protected]