Health Occupations Lymphatic System

Functions of the Lymphatic System Works in conjunction with CV system Filters out organisms that cause disease Produces WBCs Makes antibodies Drains excess fluids & protein so tissues do not swell up

Lymphatic fluid Thin & watery Called interstitial fluid Composed of Forms when plasma diffuses into tissue spaces Composed of Water Digested nutrients Salts Hormones Oxygen CO2 Lymphocytes Metabolic wastes

Vessels & Organs of the Lymphatic System Found in almost all tissues that have blood vessels Lymphatic capillaries A. Tubes that reach into interstitial spaces B. Small, open-ended like drain pipes C. Lymph fluid contains waste products & foreign bodies from cells D. Fluid moves from capillaries to lymph vessels

Vessels & Organs of the Lymphatic System Lymphatic capillaries also have LACTEALS – specialized capillaries found in small intestine 1. Pick up digested fats 2. Lymph + Lipids = Chyle 3. Transports chyle to bloodstream via thoracic duct

Vessels & Organs of the Lymphatic System Lymphatic vessels Similar to veins Muscular contractions help to move lymph from tissues to lymphatic trunks Valves prevent backflow of lymph so it moves in only one direction, towards heart Fluid empties in lymphatic trunks which empty into veins & then become part of the blood plasma

Vessels & Organs of the Lymphatic System Lymph nodes Lie along lymph vessels Small, round or oval masses Size of pinhead to almond Usually found in groups or clusters Job is to filter lymph & remove impurities like carbon, CA, pathogens, dead blood cells Also produce lymphocytes & antibodies Purified lymph with lymphocytes & antibodies added leave node via ONE lymphatic vessel Found in neck, armpit, chest, abdomen, elbows, groin, knees

Vessels & Organs of the Lymphatic System Lymphatic ducts – all lymph vessels drain into these Right lymphatic duct Short tube receiving all purified lymph from right side of head, neck, right chest, & right arm Drains into right subclavion vein Thoracic duct Drains purified lymph from rest of body Empties into left subclavion vein Cisterna chili – enlarged pouch like structure @ start of thoracic duct Serves as storage area for purified lymph before it returns to blood stream Picks up chyle (digested lipids) from lacteals

Vessels & Organs of the Lymphatic System Tonsils Masses of lymph tissue that are external Filter interstitial fluid, not lymph If too much bacteria is filtered, pathogen can overwhelm tonsils & they can become infected 3 pairs of tonsils Palatine tonsils – on each side of soft palate Pharyngeal tonsils – adenoids, in nasopharnyx Lingual tonsils – on back of tongue

Vessels & Organs of the Lymphatic System Spleen A. Organ located beneath left side of diaphragm & behind upper stomach B. Filters microorganisms & wastes C. Makes lymphocytes & monocytes D. Destroys old erythrocytes & stores RBCs to release into bloodstream if there is excessive bleeding E. Destroys platelets

Vessels & Organs of the Lymphatic System Thymus Mass of lymphatic tissue located in front of aorta & behind sternum Stores lymphocytes to defend body only in CHILDREN Atrophies after puberty & is replaced by fat & connective tissue During childhood, makes lymphocytes & antibodies Function is taken over by lymph nodes in adults

Immunity Lymph system helps body remove foreign & harmful substances 1. Antigen – foreign matter that causes body to produce antibodies (poison, splinter, bacteria) 2. Antibody – substance made by body to produce immunity to antigen

2 forms of immune response Nonspecific – innate, provides general protection Barrier of skin, mucous membranes, tears, leukocytes 1. Forms antibodies in response to antigens or foreign material Inflammatory response - localized Injured cells cause release of chemicals, causing vascular dilation & increased blood flow Other molecules enter area, wall off injured tissue Bacteria are destroyed by WBCs Area is red, warm, painful, & often swollen with decreased function

2 forms of immune response Inflammatory response – systemic Affects entire body Same as localized, but with increased neutrophils, fever, & fluid loss in tissues If not stopped, can lead to shock & death Specific immunity A. Inherited – develops before birth, is genetic (example – humans don’t contract simian AIDS)

2 forms of immune response B. Acquired 1. May be natural or artificial, depends on how it was attained a. Natural acquired unintentional exposure like immunity from breast milk b. Artificial acquired obtained intentionally like immunization

Immune response may damage tissue With allergen exposure, plasma & memory cells produced. The next exposure causes anaphylactic response Cytoxic response when antibodies react with cells causing cellular destruction (RH incompatability) Phagocytes released to remove antigen-antibody complexes & their actions cause by-products that can cause tissue damage Delayed hypersensitivity – occurs more than 12 hours after exposure & results in tissue damage

Abnormal conditions Lymphadenitis – inflammation or infection of lymph nodes A. Occurs when large amounts of harmful substances enter lymph nodes B. Symptoms – fever, swollen, painful nodes C. If untreated, nodal abscess may form D. Treatment – warm moist compresses, antibiotics, occasionally drain abscess

2. Hodgkin’s lymphoma Chronic, malignant disease of lymph nodes Most common form of lymphoma Symptoms Painful swelling of nodes Fever Night sweats Weight loss Fatigue Pruritis (itching) Treatment Chemo & radiation

3. Lymphangitis Inflammation of lymph nodes, usually from infected extremity Symptoms Red streak extending up an arm or leg from source of infection Fever Chills Pain or tenderness Treatment Antibiotics Rest & elevation Warm, moist compresses

4. Lymphedema Caused by lymphatic obstruction Commonly occurs after lymph node removal Especially after mastectomy

5. Splenomegaly Enlargement of spleen Causes Symptoms Abnormal accumulation of RBCs Mononucleosis Cirrhosis of liver Symptoms Swelling & abdominal pain Can lead to anemia, leucopenia, thrombocytopenia If spleen ruptures, hemorrhage & shock, if untreated, death May need to remove spleen

6. Tonsillitis Inflammation or infection of tonsils Usually pharyngeal or palatine tonsils Symptoms Throat pain Dysphagia (difficult swallowing) Fever Exudate on tonsils Swollen mandibular lymph glands Treatment Antibiotics Warm saline irrigations Analgesics May remove with chronic infection or enlargement