Final answer:
Pathogens can enter the body through various portals such as the skin, mucous membranes, and parenteral routes. Common entry points include the respiratory, gastro-intestinal, and urogenital tracts, as well as mucosal surfaces around the mouth, nose, eyes, and other orifices.
Step-by-step explanation:
Examples of a portal of entry for pathogens include the skin, mucous membranes, and parenteral routes. Pathogens can gain access into the body at various sites, with the most common portals of entry being areas that are directly exposed to the external environment or through breaks in the protective barriers. For instance, the skin typically acts as a barrier to pathogens but can be compromised through wounds or insect bites. Mucosal surfaces, such as the respiratory, urogenital, and gastrointestinal tracts, are particularly important portals of entry where microbes can gain access.
Pathogens may also enter the body through orifices like the mouth, nose, eyes, genitalia, and anus, where the mucosa offers a potential entry point. These entry points are vulnerable because they are constantly in contact with external particles that may include microorganisms. Some pathogens enter by swallowing and access the body through the mucosa lining the digestive tract, while others may breach the skin and enter the host.