Jerry is driving and suddenly sees a police car with flashing lights in his rearview mirror. He also hears a siren blaring. Jerry begins to panic and is afraid that he is being pulled over; however, the blaring siren passes Jerry. After the police car pulls over another driver, Jerry's heartbeat soon slows down, his blood pressure decreases, and he stops sweating. These calming physical reactions are MOST directly regulated by his nervous system.