Lymphatic & Immune System

Function and Structures of the Lymph System Two functions of the lymphatic system: 1. Absorb fats and vitamins from digestive system 2. Return waste products and extra fluid to circulatory system Structures of the lymphatic system: 1. Lymph fluid, lymph vessels, lymph nodes, tonsils, spleen, thymus, lymphocytes See Figures 6.1 and 6.2, p. 106

Structures of the Lymphatic System Lymph fluid – removes waste from cells, filtered by lymph nodes before re-entering circulatory system Lymph vessels – have valves, always flow toward the thoracic (chest) cavity Lymph nodes – location of lymphocyte production; nodes filter lymph fluid of harmful substances; swollen lymph nodes may mean there is a disease process See figure 6.3, p. 107

Structures of the Lymphatic System Tonsils – masses of lymphatic tissue located in back of mouth on sides of throat Spleen – filters blood, makes lymphocytes & monocytes, removes old RBC’s Thymus – located above the heart, important in immune and endocrine systems

Pathology of the Lymphatic System Lymphadenitis - (lymphaden/o + -itis) inflammation of lymph nodes Lymphadenopathy – (lymphaden/o + -pathy) disease of lymph node Lymphedema – (lymph/o + -edema) swelling from lymph fluid accumulation Splenomegaly – (splen/o + -megaly) enlargement of the spleen

Function of the Immune System 1. Protect the body from harmful substances such as microorganisms, allergens, poisons, malignant cells 2. Structures include tonsils & adenoids, bone marrow, appendix, spleen, thymus, skin, lymph nodes and vessels

Defense Mechanisms First Line of Defense 1. Skin – barrier against organisms entering the body 2. Respiratory system – traps inhaled foreign matter, coughing & sneezing helps remove matter 3. Digestive system – uses acids and enzymes to destroy organisms swallowed or eaten in food 4. Lymphatic system – fight invaders after they enter body

Types of Immunity Immune Response – activated when a foreign substance (antigen) enters the body, proteins (antibodies) bind to the antigen to mark it so that other cells in the immune system can destroy the antigen Types of Immunity 1. Natural Immunity – passed from mother to fetus before birth 2. Acquired Immunity – development of antibodies following a disease (ex. chicken pox) 3. Artificial Immunity – immunity acquired from vaccination (ex. MMR, tetanus, hepatitis, etc…)

Pathology of the Immune System Pathology of Immune System 1. Allergic Reaction – overreaction by the body to an antigen (see figure 6.7, p. 111) 2. Anaphylaxis – severe allergic reaction, can be fatal without rapid treatment 3. Human Immunodeficiency Virus (HIV) – bloodborne pathogen that invades and kills cells of the immune system 4. Acquired Immunodeficiency Syndrome (AIDS) – advanced stage of HIV

Pathogenic Organisms Pathogenic Organisms (Path/o = disease + genic = creation or reproduction) See figure 6.9, p Bacteria – one-celled microscopic organism (ex. Staph or strep) 2. Fungus – parasitic plant 3. Yeast – type of fungus 4. Parasite – plant or animal living in another organism (example malaria) 5. Virus – invade cells, reproduce, and spread to other cells Examples of viruses: chickenpox, mono, measles, rabies

Treatments / Medications Medications to treat infections 1. Antibiotics – used to treat bacterial infections (anti = against + bi/o = life + -tic = pertaining to) 2. Antivirals – used to treat viral infections Oncology – study of the prevention, cause and treatment of cancer

Tumors Terms related to tumors: 1. Neoplasm – new, abnormal tissue formation 2. Benign – not malignant, favorable recovery 3. Malignant – harmful, tends to spread, become worse or life threatening 4. Metastasize – cancer that spreads from one place to another

Cancer Types of Cancer: 1. Carcinoma – malignant tumor in the epithelial layer of tissue (carcin = cancerous + -oma = tumor) 2. Sarcoma – malignant tumor in the connective tissue (sarc- = flesh) 3. Lymphoma – malignancy in the lymphatic system 4. Blastoma – malignancy of immature cells (blast = immature)

Cancer Cont’d. Breast Cancer – malignant tumor that develops from the cells of the breast. Detection of breast cancer – breast self exam, mammogram, biopsy

Cancer Treatments 1. Surgery – removing the malignancy (tumor) plus some of the surrounding normal tissue 2. Chemotherapy – use of toxic chemical agent and drugs to destroy malignant cells 3. Radiation – treatment of cancer through x-rays

Career Opportunities 1. Cytotechnologist – laboratory tech who examines cell samples 2. Lymphedema therapist – provides massage, skin care, bandaging, exercises, etc… to lymphedema patients