Final answer:
The term 'endogenous' refers to something produced within the body, differentiating it from 'exogenous' which applies to substances originating externally.
Step-by-step explanation:
The word that means "produced within the body" is endogenous. In contrast, exogenous refers to substances or processes that originate from outside an organism. The word occluded typically relates to something being obstructed or closed off, while paroxysmal describes a sudden increase or recurrence of symptoms.