Lecture Notes on Disease and Immunity

Morbidity and Mortality

  • Morbidity: Incidence of a specific notifiable disease.

  • Mortality: Deaths from a notifiable disease.

Reservoirs of Infection

  • Living Reservoirs:

    • Zoonoses: Diseases transmitted from animals to humans.

  • Non-living Reservoirs:

    • Soil

    • Water

Transmission Types

  • Contact

  • Vehicle

  • Vectors

Inflammation

(Chap 16)

Immunity

  • Immunity: Resistance to or ability to ward off disease.

  • Susceptibility: Lack of resistance to a disease.

  • Innate Immunity: Non-specific resistance against any pathogen.

  • Adaptive Immunity: Immunological memory to resist specific pathogens.

Lines of Defense

  • 1st Line of Defense: Skin and mucous membranes.

  • 2nd Line of Defense: Natural killer cells, leukocytes, and macrophages.

Hematopoiesis

  • Hematopoiesis: Takes place in red bone marrow.

Leukocytes and Lymphocytes

  • Leukocytes: White blood cells that protect the body.

  • Lymphocytes: T cells, B cells, and natural killer cells.

  • Granulocytes: Leukocytes with large granules in the cytoplasm that are visible.

  • Agranulocytes: Leukocytes with granules that are not visible.

Chemotaxis

  • Chemotaxis: Chemical signals attract phagocytes to microorganisms.

Phagocytosis Steps

  • Adherence: Attachment of a phagocyte to the surface of the microorganism.

  • Ingestion: Microorganism is coated with proteins.

  • Digestion/Discharge: Microorganism is digested inside a phagolysosome, and waste products are ejected from the cell.

Inflamation Steps

  • Steps:

    • Vasodilation

    • Migration

    • Repair

Antibodies

  • IgIg (immunoglobulin) = antibody

    • Ig−GIg-G: Found in blood

Cell Types

  • T cell

  • B cell