Immune System

  • Dendritic Cells:
    These cells detect the invading pathogen and capture its antigens. They travel to the lymph nodes and present these antigens to Helper T Cells, activating the immune response.

  • Helper T Cells:
    After receiving the antigen from dendritic cells, Helper T Cells coordinate the immune attack. They activate other cells like Killer T Cells, Macrophages, and B Cells, directing the response.

  • Neutrophils:
    As the first line of defense, Neutrophils rush to the site of infection. They attack pathogens directly with granules or traps (NETs), killing as many invaders as possible.

  • Macrophages:
    Macrophages clean up the battlefield by engulfing and digesting pathogens and dead cells. They also send signals (cytokines) to recruit more immune cells if needed.

  • Killer T Cells:
    Killer T Cells seek out and destroy infected cells by triggering them to undergo apoptosis, preventing the spread of infection.

  • Plasma B Cells:
    Activated by Helper T Cells, Plasma B Cells produce antibodies specific to the pathogen's antigens. These antibodies tag the pathogen for easier destruction by other immune cells.

  • Memory B Cells:
    Once the infection is cleared, Memory B Cells retain information about the pathogen. This ensures a faster and more effective response if the same pathogen invades again. They attack anything bad in our bodies.

  • Innate immune system: first response and general defense; will attack anything they think is bad. They include the Dendritic Cells, Neutrophils, and Macrophage

  • Adaptive immune system: second to respond after innate, it is activated by the Dendritic Cell. It’s a specific immune response for one disease. It includes the Helper T Cell, Killer T Cell, Plasma B cell, and Memory B Cell.

  • Antigen: small piece of the other/pathogen

  • Pathogen: anything foreign that can hurt us

  • Agent: what must be present for the disease to occur (virus, bacteria, chemical, physical cause, etc)

  • Environment: extrinsic factors that impact agent and opportunity for exposure (climate, insects, socioeconomic status, living conditions, etc)

  • Host: Human that gets the disease

  • Component Cause: individual pie pieces/ factors

  • Sufficient Cause: the complete pie that leads to disease

  • Necessary Cause: pie pieces that show up in every pie about that disease

  • The Epidemiology Triangle vs Rothman’s Casual Pie: pie is better because it can also be used for non infectious disease unlike the triangle