Lymphatic & Immune Systems

Lymphatic System Anatomy

  • Includes adenoids, tonsils, lymph nodes, thymus, spleen, lymph vessels, and bone marrow.

Lymphatic System Overview

  • Network of vessels acting as the body's drainage system.
    • Lymph nodes: Produce and store lymphocytes; filter lymph.
    • Lymph nodules: Masses of lymphoid tissue; not encapsulated.
    • Spleen: Filters blood; largest lymphoid organ.
    • Tonsils/adenoids: Protect the entrance to the digestive system.
    • Thymus: Produces and matures T-cells.
    • Interstitial fluid: Becomes lymph after collection and filtration.

Immune System Overview

  • Defends the body against infection while protecting its own cells.
  • Remembers past infections for rapid response.
    • Relies on the lymphatic system.
    • B-cells and T-cells: Major defense components.

Immune System Cells

  • Antigen: Foreign substance in the body.
  • Antibody: Protein created in response to antigens; also called immunoglobulins.
  • B-cells: Recognize antigens and create antibodies.
  • T-cells: Recognize and attack antigens directly.
  • Monocytes: Engulf and destroy pathogens.

Mononucleosis

  • Transmitted through saliva.
  • Common in adolescents and young adults.
  • Can cause enlarged spleen.

Symptoms

  • Fatigue, sore throat, fever, swollen lymph nodes and tonsils, headache, skin rash, soft/swollen spleen.

Inflammation

  • Body's response to injury or infection.
  • In autoimmune disorders, it occurs unnecessarily.

Fever

  • Sign of an underlying condition.
  • Increase in body temperature, causing discomfort.

Immune System Disorders

  • Autoimmune: Overactive immune system attacks healthy cells/tissues.
  • Immunodeficiency: Underactive immune system is vulnerable to infection.

Autoimmune Examples

  • Rheumatoid arthritis, lupus, IBD, multiple sclerosis, type 1 diabetes.

Allergies

  • Extreme response to foreign substances.
  • Symptoms include runny nose, watery eyes, sneezing, hives, anaphylaxis.

Allergy Testing

  • Skin prick: Immediate reactions.
  • Patch testing: Detects delayed reactions.

Allergy Treatment

  • Mild: Over-the-counter medication.
  • Severe: Epinephrine auto-injector.

Common Allergens

  • Environmental irritants, pollen, dairy products, insect bites/stings, pet dander, nuts, medications.