Joe Pistack MS/ED

 The lymphatic system contains:  Lymph  Lymphatic vessels  Lymphoid organs  Lymphoid tissue Lymphoid tissue is scattered widely throughout the body.

 Lymphatic vessels return tissue to the blood.  Specialized lymphatic vessels play an important role in intestinal absorption of fats and fat soluble vitamins.  Lymphoid tissue helps the body defend itself against disease.

 Lymphedema-lymph channels back up and there is a back-up of interstitial fluid.

 Lymph is a clear fluid that resembles plasma.  Composition:  Water  Electrolytes: Na+, Cl.  Waste from metabolizing cells.  Some albumin that leaks out of the capillaries.

 Has a similar structure to the blood capillaries and the veins.  Has the same distribution as the blood capillaries and veins.

 Lymph flows toward the heart through a series of lymphatic vessels until it reaches the lymphatic ducts.  Lymph from the rest of the body drains into the thoracic duct.

 Both ducts empty the lymph into the subclavian veins.  Right lymphatic duct drains lymph into the right subclavian vein.  Thoracic duct drains lymph into the left subclavian vein.

 Includes:  Lymph nodes  Tonsils  Thymus gland  Spleen  Lymphoid organs and lymphoid tissue help defend the body against disease.

 Lymph nodes – small pea-shaped patches of lymphatic tissue strategically located so as to filter the lymph as it flows through the lymphatic vessels.  Lymph nodes tend to appear in clusters.

 Cervical lymph nodes:  Drain and cleanse lymph coming from the head and neck areas. Enlarged tender cervical lymph nodes often accompany upper respiratory infections.

 Axillary lymph nodes- located in the axillary, or armpit. Drain and cleanse lymph coming from the upper extremities, shoulder, and breast area. Cancer cells that escape from the breast are often found in the axillary lymph nodes.

 Located in the groin region. Drain and cleanse lymph from the lower extremities and external genetalia.

 Tonsils-partially encapsulated lymph nodes in the throat area.  Filter tissue fluid contaminated by pathogens that enter the body through the nose or mouth or both.  Three sets of tonsils.

 Small masses of lymphoid tissue located at the opening of the oral cavity into the pharynx.  Set of tonsils removed in a tonsillectomy.

 Also called adenoids.  Located near the opening of the nasal cavity in the upper pharynx.  Enlargement of the adenoids may interfere with breathing.

 Located at the back of the tongue.

 Located in the upper mediastinum in thoracic cavity.  Plays a crucial role in the development of the immune system before birth and in the first few months after birth.

 Gland shrinks after puberty but remains active throughout life  Thymosins- hormone secreted by the thymus gland.

 Largest lymphoid organ in the body.  Located in the upper left quadrant of the abdominal cavity.  Filters blood rather than lymph.

 Composed of two types of tissue:  (1) white pulp-lymphoid tissue consisting primarily of lymphocytes surrounding arteries.  (2)-red pulp-contains venous sinus filled with blood and disease-preventing cells such as lymphocytes and macrophages.

 Cleansing role  Stores blood, especially platelets  Destroys and phagocytes, old worn-out blood cells (called the graveyard of blood cells)  Plays a role in erythropoiesis (site of red blood cell production) before birth  Production of lymphocytes  Can live without a spleen, more prone to infection