The Lymphatic System

1. The Lymphatic System B&S CHAPTER 16

2. The Lymphatic System • Can be considered a supplement to the circulatory system • The lymphatic system is different from the circulatory system in that it has no muscular pump or heart (just like the veins) and lymph fluid travels in only one direction: from the body organs to the heart. Lymph fluid does not flow continually through vessels forming a closed circular route • The Lymphatic system contains lymph, lymph vessels, lymph nodes, tonsils, Thymus, and spleen

3. Remember in circulation… • Blood travels throughout the body and returns to the heart via the inferior and superior vena cava • The blood carries nutrients, water, waste, O2, electrolytes and bunches of other stuff • As the blood flows around the body, it drops off waste to be filtered out of the kidneys and liver (through the hepatic portal system), it continues to carry “stuff” to cells also, that lie in tissues. Tissues get juicy and full of liquid and “stuff” • Another system carries fluids out of the tissues through the filtering lymph nodes and on out to a large vein that dumps into the heart

4. Functions of the Lymph System • 1. Drains protein containing tissue fluid (interstitial fluid) back to the heart • 2. Transports fats from lacteals digestive tract and eventually through the heart which will flow out of the heart and to the blood • 3. Produce lymphocytes – (needed for fighting infection) • 4. Develops immunities

5. Lymphatic System • Lymphatic capillaries – these tiny vessels are in addition to blood carrying capillaries, they drain excess fluid that doesn’t return to the blood, but it goes directly to the heart • Remember, tissue gets juicy and filled with nutrients but what will help get rid of all of the liquid so the person doesn’t get too edematous? The lymph system  • The lymphatic system is sort of its own fluid and waste carrying system separate from the veins and arteries, but it makes it’s exchange of fluids and wastes initially, in the capillary exchange area

7. A Straw… • There are no ends of the lymph system that actually attach to the veins or arteries therefore… • Waste and nutrients just float on over from capillaries into the surrounding tissue where they get juicy and the closed ended lymph vessels pick up all of the juice and nutrients and carry it away

8. Lymph fluid • Is straw colored fluid, similar in composition to blood plasma • Lymph fluid bathes the surrounding spaces between tissue cells and it is referred to as interstitial fluid or tissue fluid • Lymph fluid is made up of water, lymphocytes, granulocytes, O2, digested nutrients, hormones, salts, CO2 and urea

9. Lymph Fluid is… • Collected from body tissues, lymph seeps into lymphatic vessels across the vessel’s thin walls • Lymph acts as an intermediary between the blood in the capillaries and the tissues. • It carries digested food, O2 and hormones to cells • It carries metabolic waste products like CO2 and urea wastes away from the cells and back into capillaries for excretion

10. Lymph • Before the lymph reaches veins near the right side of the heart, it flows near through a series of filters called the lymph nodes where bacteria and other foreign particles are trapped and destroyed • It’s sort of a system like the hepatic portal system, stuff makes its way through theses vessels to get filtered and then continues back to the heart

11. Lymphatic Circulation • One-way system • Begins in tissues • Ends in veins near the heart

12. How does the Lymph System work as a pump • Contractions of skeletal muscles against lymph vessels cause the lymph to surge forward into larger vessels • The breathing movements of the body also cause lymph to flow • Valves located along the lymph vessels prevent backward lymph flow

13. What do lymphatic capillaries look like • They are made up of one layer of flattened (squamous) epithelial cells, this allows for easy passage of soluble materials and water • There are gaps between these endothelial cells in the lymphatic capillaries that are larger than those of the blood capillaries to allow for easier entrance of proteins and other relatively large suspended particles

14. Lymphatic Capillaries • Begin “blindly” meaning they are closed at one end and DO NOT serve to bridge two larger vessels • One end lies within a lake of tissue fluid and the other end communicates with a larger lymphatic vessel that transports the lymph toward the vein that leads to the heart

15. Lacteals • We learned about lacteals in digestion • Lacteals are specialized lymphatic capillaries which act as a pathway for the transfer of digested fats into the bloodstream just like the villi act as a pathway for nutrients into the blood

18. Location • Lymphatic vessels lie superficial or deep • They are named according to their location:

19. Names • Mammary lymphatic vessels: located in the breast • Femoral lymphatic vessels: located in the thigh • Tibial lymphatic vessels: located in the legs

20. Upper extremities • All lymphatic vessels form networks and at certain points, they carry lymph into the regional nodes closest to where the node originates from • For example: all lymph from the upper extremities and breast pass through the axillary lymph nodes and all of the lower extremities pass through the inguinal nodes

21. 2 terminal vessels • Lymphatic vessels carry lymph away from the regional nodes and eventually drain into one of two terminal vessels: • Right lymphatic duct Thoracic duct • Receives lymph from the drains the rest of • Right side of the head, neck, the body • thorax, right extremity, it • Enters into the right subclavian

23. Right Lymphatic Duct • This duct receives only lymph that comes from the upper right quadrant of the body such as: • right side of head, neck and thorax • as well as the right extremity • These all drain into the right subclavian

24. Thoracic Duct • Is larger than the right lymphatic duct because it drains the whole rest of the body’s lymph juice from the: • Left head, chest, abdomen, pelvis and both legs

25. Thoracic Duct • Is attached to part of the diaphragm • The 1st part of the duct is enlarged to form a “cistern” or temporary storage pouch called the “cisterna Chyli” • CHYLE – (kile) is a milky fluid formed by a combo of fat and lymph that comes from the intestinal lacteals

26. Chyle • Passes through intestinal lymphatic vessels and lymph nodes of the mesentary and finally goes to its holding place known as the cisterna chyle • All of the lymph juice below the diaphragm enters into the cisterna chyle by way of various clusters of lymph nodes and then makes its way to the thoracic duct and into the heart

27. To get all of the lymph fluid from the upper body down to the heart, the jugular lymphatic vessels from the head and neck, left subcalvian vessels and other vessels in the thorax enter into the left subclavian vein

29. Movement of lymph fluid • Remember, there is no pump to push this fluid back to the heart. • It works the same way as the veins to get blood back to the heart • Valves keep it going one way, muscles contract to push fluid, pressure in the thorax from breathing pushes the fluid too

30. Our body is filled with lymph tissue that makes up specialized organs of the lymph system (tonsils, thymus, spleen) Lymph Tissue and Lymph Nodes

31. Lymph tissue’s functions: • Removes impurities like Carbon particles, cancer cells, dead blood cells and pathogenic organisms • This junk is sent to the lymph nodes where • phagocytosis from macrophages, destroy the junk • The making of lymphocytes is done in lymph tissue, this is needed to make antibodies to combat infection and other foreign invaders

32. Lymph nodes may be compared to the oil filter in an automobile Lymph Nodes

33. Lymph Nodes • They are designed to filter the lymph once it is drained from the tissues • Lymph nodes are small, rounded masses varying from pinhead size up to 1 inch • Lymph nodes have fibrous connective tissue capsules

34. Are usually massed together in groups varying from 2 or 3 to over 100 Some of these grps. of nodes are super-ficial and some are deep Lymph Nodes

35. Inside the lymph node • There are masses of lymphatic tissue which contain: • Lymphocytes • Macrophages • WBC’s active in immunity

37. Hilus • Serves as an exit for lymphatic vessels carrying lymph fluid out of the node • At the hilus, blood vessels and nerves connect with the node

38. Main Groups of Nodes In the Body • Cervical Nodes: located deep in the neck, these drain various parts of the head and neck. These often become enlarged during upper resp. infections • Axillary Nodes: located in the armpits, may become enlarges after infections of the upper extremities and the breasts. Cancer cells from the breast often metastasize (spread) to axillary nodes

40. Main Groups of Nodes In the Body • Tracheobronchial: nodes are found near the trachea and around the larger bronchial tubes. People living in highly polluted areas have these nodes that are filled with carbon particles that are solid black masses resembling pieces of coal

41. Main Groups of Nodes In the Body • Mesenteric Nodes: these are found between 2 layers of peritoneum that form the membrane around the intestines called the mesentary. There are 100 to 150 of these nodes

42. Main Groups of Nodes In the Body • Inguinal Nodes: located in the groin region, these receive lymph drainage from the lower extremities and from the external genital organs. When they are enlarged, they are referred to as “buboes” (bu-bose), from which Bubonic plague got its name

43. Biopsy or removal • Any lymph node can be biopsied or removed if necessary

44. The Tonsils • These are masses of lymphoid tissue that are oval shaped and are located at each side of the soft palate • These are also called “palatine tonsils” • In adults, removal of tonsils causes lots of bleeding and leads to hemoptysis

46. Pharyngeal tonsil (Adenoids) • Commonly called adenoids, means “glandlike” • These are located behind the nose on the back wall of the upper pharynx • These can be removed also (adenoidectomy)

47. Infection of the tonsils • Either of these tonsils can become loaded with bacteria and they may be removed (tonsillectomy) • Drs. Believe that strep throat of at least 5xs in one season calls for the removal of the tonsils

49. Tonsils and immunity • Tonsils function in immunity during childhood. They filter tissue fluid and they produce lymphocytes and monocytes and contain macrophages that eat up pathogens that get through • Drs. Try and not remove them if possible • Tonsils in children are bigger than in adults d/t body size

50. T&A • If a pt is having their tonsils out, they will probably have their adenoids out as well, this is referred to as a T&A • This can be done out-patient unless pt has sleep apnea, pt stays overnight to watch for swelling and complete closure of airway • What pieces of equip. are needed for this pt?