CHAPTER 6: THE LYMPHATIC AND IMMUNE SYSTEMS

The Lymphatic System  Functions and Structures –Lymph Fluid –Lymph Vessels –Lymph Nodes –The Tonsils –The Vermiform Appendix –The Spleen –The Thymus  Pathology and Diagnostic Procedures –Lymphadenitis –Lymphadenopathy –Lymphangiogram –Lymphangioma –Lymphedema –Splenomegaly –Splenorrhagia

 Primary functions of the Lymphatic System are: –Return cellular waste products and excess fluid from the tissues to the circulatory system –Absorb fats and fat-soluble vitamins from the digestive system and transport them to the cells –Serve as an important part of the immune system

Lymph Fluid/Vessels/Nodes  Lymph: –Lymph fluid, also known as interstitial fluid, intercellular, or tissue fluid is a form of plasma that comes out from the capillaries and into the spaces to provide food, oxygen, and hormones to the cells. –Lymph is the remaining or left over that fluid that has not been reabsorbed. It removes cellular waste products, pathogens, and dead blood cells from the surrounding tissues.  Lymph Vessels –Lymph capillaries: thin tubes that carry lymph from the tissues to the larger lymph vessels. –Have one-way valves that only allow lymph flow into the thoracic cavity  Lymph Nodes: located in the lymph vessels, provide a site for lymphocyte production and removes bacteria, viruses, and malignant cells out of the lymph fluid. –Cervical: neck –Axillary: armpit –Inguinal: groin

 Tonsils –Form a protective ring around the nose an upper throat  Adenoids: located in the nasopharynx  Palatine: located in the back of the throat, visible through open mouth  Lingual: located at the base of the tongue  Vermiform Appendix –Hangs from the lower portion of the cecum on the large intestine –Located in the right lower quadrant –Peyer’s patches are located in the ileum, the last segment of the small intestine and hang from the intestinal walls.

 The Spleen –Located in the left upper quadrant, just posterior to the stomach –Filters foreign material and microorganisms from the blood –Is hemolytic: removes and destroys worn-out red blood cells –Maintains balance between red blood cells and plasma in the circulation as it stores extra RBC’s –Forms lymphocytes and monocytes (wbc)  The Thymus –Located superior to the heart –Plays important role in the endocrine/immune systems

spleen thymus tonsils appendix WBC monocyte lymphocyte

Pathology and Diagnostic Procedures – of Lymphatic Structures  Lymphadenitis: inflammation of lymph nodes  Lymphadenopathy: disease process usually involving enlargement of the lymph nodes  Lymphangiogram: Radiographic contrast study of the lymph vessels and nodes  Lymphangioma: benign mass of lymphatic vessels  Lymphedema: improper drainage of lymph vessels or veins resulting in abnormal accumulation of fluid in legs and ankles  Splenomegaly: enlargement of the spleen  Splenorrhagia: bleeding from the spleen

lymphadenectomy lymphadenitis splenectomy thymectomy tonsillectomy Allergy testing

The Immune System – functions to protect the body from harmful substances  Functions and Structures –The First Line of Defense –The Immune Response –Specialized Cells of the Immune Reactions –Immunity –Immune System Response Factors  Pathology and Diagnostic Procedures –Allergic Reactions –Autoimmune Disorders –Immunodeficiency  Treatment Procedures –Immunotherapy –Antibody Therapy –Immunosuppression

The First Lines of Defense  Intact Skin: physical barrier to protect foreign substances from entering the body  Respiratory system: filters foreign matter with nose hairs and mucous membranes, expelled by sneezing and coughing  Digestive System: destroys invaders that are swallowed or consumed with food  Lymphatic System: fights off invaders once they have entered the body

The Immune Response – destroys infectious microorganisms that enter the body through antigen-antibody reactions  Antigen: virus, bacterium, or toxin that the body regards as foreign –Stimulates immune response  Antibody: disease-fighting protein created by the immune system in response to that particular antigen  Immune Reaction: antigen-antibody reaction –Forms antigen-antibody complexes –Tags potentially dangerous antigens to be recognized and destroyed

Specialized Cells of the Lymphatic System  Lymphocytes: WBC that attack specific microorganisms –B Cells: most effective against viruses and bacteria that are circulating in the blood  Complement  Immunoglobin –T Cells: small circulating lymphocytes that have traveled to the thymus to mature and kill invading organisms on contact  Interferon  Lymphokines  Macrophage: protects the body by ingesting invading cells  Phagocyte: ingests and destroy substances such as cell debris, dust, pollen, and pathogens (phagocytosis)

 Immunity: the state of being resistant or not susceptible to a specific disease –Natural: passed from mother to child –Acquired: obtained by the development of antibodies during attack of infectious disease –Artificial: immunization  Response Factors: influence the immune system’s ability to respond –Health –Age –Heredity –Opportunistic infection: a pathogen that normally does not cause disease but is able to cause illness in a weakened host whose resistance in decreased by other disease

Pathology and Diagnostic Procedures of the Immune System  Allergic Reactions –Cellular Response: localized sensitivity to allergen Itching, hives, erythema –Systemic reaction: anaphylaxis, severe response where symptoms develop quickly and include blockage of air passages, drop in blood pressure –Scratch Test and Antihistamines: identifying and treatment of allergens  Autoimmune Disorders: immune system misreads normal antigens and develops antibodies to attack them (Tbl. 6.4) –Crohn’s Dx –Diabetes mellitus, type 1  Immunodeficiency: one or more parts of the immune system are deficient or missing –HIV: blood borne pathogen that invades and then impairs or kills cells of the immune system – AIDS = advanced stages of HIV

Scratch Test

 Treatment Procedures of the Immune System –Immunotherapy: can be used in the treatment of cancers by triggering the immune response to fight the malignancy. –Antibody Therapy: post exposure preventative measure –Immunosuppressant: treatment used to interfere with the ability of the immune system to respond to stimulation by antigens

Pathogenic Organisms  Bacteria  Fungus, Yeast, and Parasites  Viruses –Viral Infections:  Chicken Pox  Herpes Zoster  Infectious Mononucleosis  Measles  Mumps  Rabies  Rubella

Oncology  Study of prevention, causes, and treatment of tumors and cancer  Terms Related to Oncology: –Tumor: neoplasm, new and abnormal tissue formation (angiogenesis) –Benign: not recurring, nonmalignant, with a favorable chance of recovery (myoma) –Malignant: harmful, tending to spread, becoming progressively worse, and life- threatening –Carcinoma in situ: malignant tumor still in it’s original position, has not metastasized (spread from one place to another)