Untitled Quiz

Factors Determining Infection and Disease

• The primary factor that determines the establishment of infection and the resulting disease is the interplay between the virulence of the pathogen and the susceptibility of the host.

First Line of Defense

• The first line of defense against invading pathogenic microorganisms includes all, except the lymphatic system, which is part of the second line of defense.
• The first line of defense includes physical barriers, such as skin and mucous membranes, and mechanical removal of pathogens through coughing, sneezing, and tears.

Specific Immunity

• The specific immunity that primarily protects our body from intracellular pathogens like viruses is cell-mediated immunity, which involves the activation of T cells and macrophages.

Lymphocytes

• The types of lymphocytes that play a key role in both cell-mediated and humoral immune response are T cells and B cells.

Outcomes of Colonization

• The possible outcomes following colonization of a body site by a potentially pathogenic microorganism include disease, asymptomatic carriage, and commensalism.

Epithelial Layers

• Keratinized epithelia are the layers of cells that form physical barriers found in the skin and other external surfaces.
• Ciliated epithelia are specialized layers of cells that propel bacterium-laden mucin blobs out of the respiratory tract.

Natural Killer (NK) Cells

• Natural killer (NK) cells are a type of lymphocyte that can recognize and kill infected cells and tumor cells without prior antigen exposure.

Antibody Types

• The antibody type that crosses the placenta and acts as an opsonin is IgG.
• The predominant type of antibody during the primary immune response and that fixes complement is IgM.