Shot of three different kinds of medicine on a blue surface: a bronchodilator (e.g. ephedrine), anticoagulant, and birth control. A narrator mentions that some drugs work on a single system of the body. CU on each drug in turn, followed by zoom in to an image representing the system of the body it is meant to work on. Cut to over-the-counter painkillers on same blue surface. Other drugs, narrator explains, work on different systems of the body simultaneously. XCU Aspirin, followed by images of the body systems it works on. XCU Ampicillin, an antibiotic, followed by same. Even drugs designed to work only on one body system always affect the others, the narrator concludes, because the body works as a single entity.