Question

Outline what happens when a pathogen enters a wound or creates an infection (Example: a cold virus enters the respiratory tract or bacteria enter a cut in our skin).  First describe some innate responses, then tell me how the adaptive response might get recruited or activated. What is the end outcome?

Answer 1

Immunity is the state of protection from infectious disease. When the body encounters the antigen innate immunity comes into play.

Innate immunity can be seen to comprise four types of defensive barriers: anatomic, physiologic, phagocytic and inflammatory.

Anatomic barriers include: skin and mucous membrane: mechanical barrier retards the entry of microbes and acidic environment of the skin and mucus membrane retards the growth of microbes.

Physiologic barriers include temperature, low pH, chemical mediators such as lysozyme, interferons, complement lysis, toll like receptors, collectins which degrade the antigens.

Phagocytic Barriers include endocytosis or phagocytosis

Inflammatory barriers : tissue damage and infection induce leakage of vascular fluid, containing serum proteins with antibacterial activity and influx of phagocytic cells into the affected area.