Which of the following is NOT a route of entry for pathogens?

• A. Inhalation
• B. Absorption Via Dermal
• C. Ingestion
• D. Extraction

Answer: (D)

Pathogens enter the body through exposure pathways that bring them past barriers such as skin and mucous membranes. Common routes include inhalation into the respiratory tract, ingestion into the digestive system, and absorption through the skin or mucosal surfaces. The option that does not describe a way for pathogens to gain entry is extraction, which refers to removing something rather than a pathway for entry. Inhalation allows airborne or droplet-transmitted organisms to reach the lungs; ingestion brings pathogens into the digestive tract; dermal absorption can occur when pathogens contact and penetrate the skin, often through breaks or specific organisms that invade. Therefore, extraction is not a pathway for pathogens to enter the body.