Anatomy & Physiology Immune #9

Question

Which statement regarding the common portal of entries requires clarification?

Answers

  1. The skin via the direct contact route.
    • Rationale:

      The skin is a portal of entry for pathogens when direct contact is made, especially direct contact with broken skin; therefore, this statement does not require clarification.

  2. The blood via the direct contact route.
    • Rationale:

      The blood is a portal of entry for pathogens when direct contact is made; therefore, this statement does not require clarification.

  3. The respiratory tract via the direct contact route.
    • Rationale:

      The respiratory tract is a portal of entry for airborne or droplet pathogens; therefore, this statement requires clarification.

  4. The mucous membranes via the direct contact route.
    • Rationale:

      The mucous membranes are a portal of entry for pathogens when direct contact is made; therefore, this statement does not require clarification.

Overview

The chain of infection is made up of six different links: a pathogen (i.e., infectious agent); reservoir; portal of exit; means of transmission; portal of entry, and the new host.

Explanation

Learning Outcomes

A portal of entry is one of the six links in the chain of infection. A portal of entry is the “open door” through which a pathogen enters the susceptible host thereby coming in contact with an environment that is favorable for both growth and reproduction. Typically, when the respiratory tract is a portal of entry, droplets must be present for an infection to occur; therefore the statement, “The respiratory tract via the direct contact route.” requires clarification.

Test Taking Tip

Consider the routes of infection transmission to answer this question correctly.

Video Rationale