Lymphatic system (1)
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Lymphatic system (1)






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Lymphatic system (1) Presentation Transcript

  • 1. Definition The tissues and organs that produce, store, and carry white blood cells that fight infections and other diseases. This system includes the Bone Marrow Spleen Thymus
  • 2. Development Development starts by the end of the fifth week of embryonic life. The lymphatic system begins as a series of sacs 108 at the points of junction of certain of the embryonic veins. The lining walls of its vessels are always endothelial. These lymph-sacs are developed by the confluence of numerous venous capillaries, which at first lose their connections with the venous system, but subsequently, on the formation of the sacs, regain them.
  • 3. Development in Human Embryo In human embryo the lymph sacs from which the lymphatic vessels are derived are six in number. Two paired Jugular Lymph sac At the junction of the internal jugular and subclavian veins. Retroperitoneal Lymph sac At the root of the mesentery of the intestine. develops from the primitive vena cava and mesonephric veins  Posterior Lymph sacs Develop from the iliac veins
  • 4. Lymphatic System Components Lymphatic system components includes : Lymph Lymph Organs Lymph Vessels Lymph Tissues
  • 5. Lymph Lymph means clear water and it is basically the colorless fluid and protein that has been squeezed out of the blood. Lymph is a fluid similar in composition to blood plasma. Changes in plasma composition will change lymph composition.  Protein concentration of lymph is lower than in plasma and varies inversely proportional to rate of formation that varies from tissue to tissue.
  • 6. Lymph flow rate  Lymph flow rate is usually low. It is influenced primarily by the rate of lymph formation. The flow rate is affected by compression of lymphatics by negative intrathoracic pressure (breathing). Valves in the lymph vessels prevent retrograde flow similar to those in veins.
  • 7. Formation of lymph  ISF forms at the arterial (coming from the heart) end of the capillaries because of higher pressure of blood, Most of it returns to its venous ends and venules; the rest (10—20%) enters the lymph capillaries as lymph. Thus lymph formed is a watery clear liquid with the same composition as the ISF.  As it flows through the lymph nodes, however, it comes in contact with blood and tends to accumulate more cells (particularly lymphocytes) and proteins.
  • 8. Lymphatic Organs An organ that is characterized by clusters of lymphocytes and other cells, such as macrophages, enmeshed in a framework of short, branching connective tissue fibers. Formation: The lymphocytes originate in the red bone marrow with other types of blood cells and are carried in the blood from the bone marrow to the lymphatic organs.
  • 9. Types of Lymphatic organs Primary lymphatic organs Thymus gland  Bone marrow Secondary lymphatic organs  Encapsulated diffuse lymphoid tissue includes the spleen and lymph nodes.  Unencapsulated diffuse lymphoid tissue includes gut-associated lymphoid tissues and the tonsils. 
  • 10. Lymph nodes One of a number of small swellings found at intervals along the lymphatic system. They are widely distributed throughout the body along the lymphatic pathways.  Lymph nodes are not present in the central nervous system. Composed of lymphoid tissue.
  • 11. Structure of lymph nodes Small bean-shaped structures Usually less than 2.5 cm (1 inch) in length. Three superficial regions where lymph nodes tend to cluster 1. 2. 3. Inguinal nodes in the groin Axillary nodes in the armpit Cervical nodes in the neck
  • 12. Function of Lymph nodes Filter the lymph before it is returned to the blood Preventing foreign particles from entering the bloodstream They also produce lymphocytes
  • 13. Waxing, Waning of Lymph Nodes Waxing and waning terms used to describe transient or short-term fluctuations in the size of lymph nodes that could be accounted Response to treatment Immune activation against lymphoma Collapsing of necrotic areas in lymph nodes may explain a sudden decrease in a large lymph node. Lymph nodes may enlarge when immune cells react to pathogen such as virus or bacteria.
  • 14. Swollen Lymph Glands
  • 15. Tonsils Cluster of lymphatic tissue just under the mucous membranes that line the nose, mouth, and pharynx (throat) called tonsils. There are three groups of tonsils. 1. Pharyngeal tonsils 2. Palatine tonsils 3. Lingual tonsils Provide protection against harmful substances and pathogens that may enter the body through the nose or mouth.
  • 16. Enlarge Tonsil
  • 17. Spleen
  • 18. Function of Spleen Filters blood Stores blood
  • 19. Thymus Primary lymphatic organ in the body; it is located over the heart and/or in the neck area, anterior to the ascending aorta and posterior to the sternum. The thymus consists of two lobes enclosed in a capsule and is further divided internally Function of the thymus is the processing and maturation of special lymphocytes (white blood cells) called T-lymphocytes or T-cells, which are associated with antibody production.
  • 20. Lymphatics Tubular vessels transport back lymph to the blood ultimately replacing the volume lost from the blood during the formation of the interstitial fluid. Lymph capillaries Lymph vessels Lymphatic trunks Lymphatic ducts
  • 21. The two main lymph ducts are:  Right lymphatic duct  Thoracic duct Structure of lymphatics is based on that of blood vessels.  Inner lining of single flattened endothelial cells  Smooth muscles arranged in a circular fashion around endothelial cells  Outermost layer consists of fibrous tissue
  • 22. Lymphoid Tissues Specialized form of reticular connective tissue that contains various types of white blood cells enmeshed In it, most numerous being the lymphocytes. Lymphoid tissue can be of three types depending upon the stage of lymphocyte development and maturation.  Primary(central) lymphoid tissue  Secondary(peripheral) lymphoid tissue  Tertiary lymphoid tissue
  • 23. Function of Lymphoid Tissues Makes up the spleen, the thymus, and the tonsils, as well as visceral nodes, and lacteals which are all associated with mucous membranes of the gastrointestinal tract. Concerned with immune functions in defending the body against the infections and spread of tumors.
  • 24. Functions of Lymphatic System Draining fluid into the bloodstream Filtering lymph Filtering the blood helps fight infection in many ways such as Helping to make special white blood cells (lymphocytes) that produce antibodies  Having other blood cells called macrophages inside the lymph nodes which swallow up and kill any foreign particles, 
  • 25. Draining Fluid into Bloodstream