1 / 18

The Lymphatic Syste m

The Lymphatic Syste m. What is the lymphatic system?. A n extensive drainage network that helps keep bodily fluid levels in balance and defends the body against infections . Together with lymphoid organs and tissues, provide the structural basis of the immune system. Lymphatic characteristics.

sivan
Download Presentation

The Lymphatic Syste m

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Lymphatic System

  2. What is the lymphatic system? • An extensive drainage network that helps keep bodily fluid levels in balance and defends the body against infections. • Together with lymphoid organs and tissues, provide the structural basis of the immune system

  3. Lymphatic characteristics • One way system to the heart • Carries clean fluids back to the blood • Drains excess fluid from tissues • Lymph is a clear, watery fluid that contains protein molecules, salts, glucose, urea, and other substances — throughout the body. • Removes antigens from the body and exposes antigens to the immune system • Lymph may contain macrophages, viruses, bacteria, cellular debris and even traveling cancer cells.

  4. What type of vessels make up the lymphatic system? • Vessels are called lymphatics • Thin walled and analogous to veins • 2 large ducts • Right lymphatic duct • Thoracic duct • Both empty into the right and left subclavian veins Drained by the right lymphatic duct Drained by thoracic duct

  5. Lymphatic Organs • Lymph nodes • Spleen • Thymus • Tonsils • Peyer’s patches

  6. Lymph nodes • Principal lymphoid organs of the body • Most are bean shaped organs along lymphatic collecting vessels • Up to 1 inch in size • Grouped together at various parts of the body • Clusters of both superficialLNs deep

  7. Lymph nodes • Superficial • Cervical • Axillary • Inguinal • Deep • Tracheobronchial • Aortic • Iliac

  8. Circulation in the lymph nodes Afferent vessels • Lymph • Enters via afferent lymphatic vessels • Travels through large subcapsular sinus and smaller sinuses • Exits the node at the hilus via efferent vessels Efferent vessels

  9. Critical Thinking Question • Why are there more afferent lymphatic vessels carrying lymph to the lymph nodes than there are efferent lymphatic vessels? • Answer: • Fewer efferent vessels, causing flow of lymph to stagnate, allowing lymphocytes and macrophages time to carry out functions

  10. What function do lymph nodes have? • Filter lymph • macrophages destroy microorganisms and debris • Immune system—lymphocytes are activated and mount an attack against antigens

  11. Lymphangiogram

  12. Spleen • Largest lymphoid organ • Filters blood (lymph nodes filter lymph) • Filters blood of bacteria, viruses, and other debris (blood-borne antigens “white pulp” • Removes and destroys worn out red blood cells (RBCs) • Stores platelets • Site of lymphocyte production and immune surveillance and response • In fetus only: RBC are made in the spleen • Susceptible to injury; splenectomy increases risk of bacterial infection

  13. Spleen

  14. Thymus • Differs from other lymphoid organs in important ways • It functions strictly in T lymphocyte maturation • T cells become Immunocompetent • It does not directly fight antigens • Size with age • In infants, it is found in the inferior neck and extends into the mediastinum, where it partially overlies the heart • Increases in size and is most active during childhood • Stops growing during adolescence and then gradually atrophies

  15. Critical Thinking Question • Why does the thymus increases in size and is MOST active during childhood, stops growing during adolescence and then starts getting smaller? • Answer: • The thymus produces a large amount of T cells so by the time a person reaches puberty, the body has a lot of lymphocytes. The thymus also produces a variety of hormones and plays an important role in the development of immunologic competence in fetus and child.

  16. Tonsils • Simplest lymphoid organs • Form a ring of lymphatic tissue around the pharynx • Crypts trap and destroy bacteria and particulate matter

  17. Mucosa-associated lymphoid tissue (MALT) • Mucosal surfaces within the body are protected by the mucosal immune system consisting of the mucosa-associated lymphoid tissueor MALT • An extensive diffuse system of small concentrations of lymphoid tissue found in various sites of the body such as the gastrointestinal tract, thyroid, breast, lung, salivary glands, eye, and skin to protect from foreign matter.

  18. MALT • Examples: • GALT (gut-associated lymphoid tissue, such as the Peyer's patches in the lining of the small intestines, as well as the adenoids, tonsils, and appendix) • BALT (bronchial-associated lymphoid tissue in the bronchi)

More Related