Final answer:
Physical barriers block pathogens from entering the body, exemplified by the skin, while mechanical removal mechanisms, such as coughing, actively expel pathogens. Pathogens can breach physical barriers through injuries or mucous membranes.
Step-by-step explanation:
Difference Between Physical and Mechanical Removal Mechanisms
There are two types of barriers to pathogens: physical and mechanical removal mechanisms. A physical barrier blocks pathogens from entering the body, while a mechanical removal mechanism actively removes them from the body's surfaces. A classic example of a physical barrier is the skin, which acts as a protective wall preventing the entry of pathogens. On the other hand, coughing constitutes a mechanical removal mechanism as it expels pathogens out of the respiratory tract.
How Pathogens Breach Physical Barriers
Pathogens can breach physical barriers through various means such as cuts, bites, or other injuries that break the skin, or by entering through mucous membranes like those found in the mouth or nose.