Final answer:
Expectorate refers to the act of coughing up and spitting out mucus from the respiratory tract, a key protective mechanism to clear the airways and prevent infections. The correct definition for the term expectorate is C) cough up and spit out mucus from the respiratory tract.
Step-by-step explanation:
The correct definition for the term expectorate is C) cough up and spit out mucus from the respiratory tract. When debris, pathogens, or mucus accumulate in the respiratory tract, the body's natural defense mechanisms like cilia move them towards the throat. Then, through the process of coughing, this material, now known as phlegm, is expelled from the airways. The forceful expulsion of air from the trachea helps in removing the mucus which can then be expectorated (spit out) or swallowed.
Expectorating mucus is crucial for respiratory health, as it clears the respiratory passages and allows for clearer breathing. This action is protective, meant to keep the airways free of irritants and to prevent infection. An example of when expectoration is increased is during respiratory conditions like bronchitis, where inflammation leads to excess mucus production.