Lymphatic and Immune Systems Flashcards

Functions of the Lymphatic System

• Absorbs fats and fat-soluble vitamins.
• Removes waste and destroys pathogens.
• Returns filtered lymph to veins.

Interstitial Fluid and Lymph

• Interstitial fluid: Plasma from arterial blood, delivers nutrients to cells, 90% returns to bloodstream.
• Lymph: Clear fluid with electrolytes and proteins, protects the body, 10% of interstitial fluid.

Structures of the Lymphatic System

• Lymphatic Circulation: Lymph flows in one direction and is filtered by lymph nodes.
• Lymphatic Capillaries: Microscopic, blind-ended tubes near the body surface; cells separate to allow lymph entry.
• Lymphatic Vessels and Ducts:
  • Lymphatic vessels prevent backward flow.
  • Right lymphatic duct: Drains right side of head and neck, upper right quadrant, and right arm.
  • Thoracic duct: Drains left side of head and neck, upper left quadrant, left arm, lower trunk, and both legs.
• Lymph Nodes: Cervical, axillary, and inguinal nodes.
• Lymphocytes (Lymphoid Cells):
  • Leukocytes from bone marrow, defend against antigens.
  • Natural killer cells (NK cells): Kill cancer and virus-infected cells.
  • B cells (B lymphocytes): Produce antibodies, transform into plasma cells to destroy antigens.
  • T cells (T lymphocytes): Central role in cell-mediated immunity.
  • Cytokines: Proteins (e.g., interferons, interleukins) that act as intracellular signals.
  • Interferons: Activate the immune system, fight viruses, and signal other cells.
  • Interleukins: Direct B and T cells to divide and proliferate.

Additional Structures

• Tonsils: Lymphoid tissue around the nose and throat.
  • Adenoids: In the nasopharynx.
  • Palatine tonsils: Sides of the throat.
  • Lingual tonsils: Base of the tongue.
• Thymus Gland: Lymphoid tissue above the heart, matures lymphocytes into T cells.
• Appendix: May play a role in the immune system.
• Spleen: Filters blood, forms lymphocytes and monocytes, destroys old erythrocytes, stores extra erythrocytes.

Immune System

• Primary Function: Protects from harmful substances (pathogens, allergens, toxins, malignant cells).
• First Line of Defense:
  • Intact Skin: Physical barrier, acid mantle.
  • Respiratory System: Traps foreign matter.
  • Digestive System: Acids and enzymes destroy invaders.
  • Lymphatic System: Destroys pathogens.
• Antigen–Antibody Reaction: Binding of antigens to antibodies, labels dangerous antigens.
• Tolerance: Unresponsiveness to specific antigen.
• Antibodies: Disease-fighting proteins.
• Phagocytes: Destroy substances via phagocytosis.
• Monocytes: Become macrophages and dendritic cells.
• Macrophages: Kill invading cells.
• Dendritic cells: Alert B and T cells.
• Complement System: Proteins that dissolve and remove pathogens.
• Immunity:
  • Natural immunity: Present without exposure.
  • Acquired immunity: From having had the disease.
  • Vaccination: Protection with periodic boosters.

Medical Specialties

• Allergist: Treats allergic reactions.
• Infectious disease specialist: Treats diseases caused by microorganisms.
• Immunologist: Treats immune system disorders.
• Lymphologist: Treats lymphatic system disorders.
• Oncologist: Treats malignant disorders.

Lymphatic System Pathology

• Lymphadenitis: Inflammation of lymph nodes.
• Lymphadenopathy: Disease affecting lymph nodes.
• Lymphangioma: Benign tumor of lymphatic vessels.
• Ruptured Spleen: Torn covering of the spleen.
• Splenomegaly: Enlarged spleen.
• Lymphoscintigraphy: Detects lymphatic vessel damage.
• Lymphedema: Swelling due to lymph accumulation.
  • Primary lymphedema: Hereditary, swelling starts in feet.
  • Secondary lymphedema: Caused by damage to vessels.
• Bioimpedance spectroscopy: Diagnoses lymphedema.

Immune System Pathology

• Allergic Reactions:
  • Allergy (hypersensitivity): Overreaction to antigen.
  • Localized allergic response: Cellular reaction.
  • Systemic reaction: Anaphylaxis.
  • Scratch test: Identifies allergens.
  • Antihistamines: Relieve allergy symptoms.
• Autoimmune Disorders: Immune system attacks own tissues.
• Immunodeficiency Disorders: Compromised immune response.
  • Severe combined immunodeficiency (SCID).
  • Human immunodeficiency virus (HIV).
  • Acquired immunodeficiency syndrome (AIDS).
  • Opportunistic infection: Illness in healthy humans.
  • Kaposi’s sarcoma: opportunistic infection associated with HIV; cancer
  • ELISA: Screens for HIV.
  • HIV differentiation assay: Confirms positive ELISA.

Immune System Treatment

• Immunotherapy (Biological therapy): Stimulates or represses immune response.
• Antibody Therapy:
  • Synthetic immunoglobulins.
  • Synthetic interferon.
  • Monoclonal antibodies.
• HIV Treatment:
  • Antiretroviral therapy (ART).
  • Pre-exposure prophylaxis (PrEP).
  • Post-exposure prophylaxis (PEP).
• Immunosuppression:
  • Immunosuppressant: Prevents immune response.
  • Corticosteroid drug: Synthetic hormone.
  • Cytotoxic drug: Kills or damages cells.

Pathogenic Organisms

• Pathogen: Microorganism causing disease.
• Bacteria: One-celled organisms.
  • Examples: Bacilli, Anthrax, Rickettsia, Shigella, Streptococci.
• Antibiotic-Resistant Bacteria: Resistant to drugs.
  • Methicillin-resistant Staphylococcus aureus (MRSA).
• Fungus and Yeast Infections:
  • Fungus: Tinea pedis, Aspergillosis.
  • Yeast: Candidiasis, Candida albicans, Vaginal candidiasis.
• Parasites: Organisms living at the expense of others.
  • Giardiasis, Malaria, Toxoplasmosis, Trichomoniasis.
• Viral Infections: Invade cells to reproduce.
  • Examples: COVID-19, Ebola, Measles, Rabies, West Nile Virus.
• Herpesviruses: Cause various diseases.
  • Examples: Cytomegalovirus (CMV), Varicella (chickenpox), Herpes zoster (shingles), Infectious mononucleosis, Roseola.
• Medications:
  • Antibiotics: Inhibit bacterial growth.
  • Bactericide: Kills bacteria.
  • Bacteriostatic agent: Slows bacterial growth.
  • Antifungal: Destroys fungi.
  • Antiviral drug: Treats viral infections.

Oncology

• Tumors (Neoplasms):
  • Benign tumor: Non-cancerous.
  • Malignant tumor: Cancerous.
  • Angiogenesis: Tumor creates blood supply.
  • Antiangiogenesis: Disrupts blood supply.
• Cancer: Uncontrolled cell division.
  • Metastasize: Spread to other sites.
  • Metastasis: Process of spreading.
• Carcinomas: Malignant tumors in epithelial tissue.
  • Carcinoma in situ: Has not invaded surrounding tissues.
  • Adenocarcinoma: From glandular tissue.
• Sarcomas: Malignant tumors in connective tissues.
  • Hard-tissue sarcomas: Bone or cartilage.
  • Soft-tissue sarcomas: Muscle, fat, etc.
• Staging Tumors: Classifying tumors.
• Lymphomas: Malignancies affecting lymphoid tissues.
  • Hodgkin’s lymphoma (HL).
  • Non-Hodgkin’s lymphoma (NHL).
• Breast Cancer:
  • Carcinoma developing from breast cells.
  • BRCA1 and BRCA2 genes
  • Examples: Ductal carcinoma in situ (DCIS), Infiltrating ductal carcinoma (IDC), Inflammatory breast cancer (IBC), Male breast cancer
• Stages of Breast Cancer: Stage I, II, III, IV.
• Detection: Mammography, Surgical biopsy, Lymph node dissection.
• Treatment: Hormone therapy, Surgery (Lumpectomy, Mastectomy), Breast reconstruction.

Cancer Treatments

• Surgery: Removes malignancy.
• Laser surgery: Destroys cancer cells with light.
• Cryosurgery: Freezes cancerous cells.
• Chemotherapy: Destroys malignant cells.
• Chemoprevention: Reduces cancer risk.
• Antineoplastic: Blocks growth of malignant cells.
• Radiation Therapy: Destroys cancerous tissues.
  • Brachytherapy: Radioactive materials implanted.
  • Teletherapy: Radiation from a distance.
  • Tomotherapy: Tomography with radiation.
• Additional Therapies:
  • Targeted therapy: Attacks specific cancer cells.
  • Adjuvant therapy: Decreases chance of recurrence.
  • Clinical trials: Testing new treatments.

Abbreviations

• Antibody = Ab
• Cancer = CA, Ca
• Herpes zoster = HZ
• Non-Hodgkin’s lymphoma = HL
• Immunoglobulin = IG
• Metastasis = MET