Final answer:
Early pain control methods included using opium, scaring off demons, and employing roots, berries, and seeds; with opium and its derivatives like morphine and codeine still playing an important role in modern pain management.
Step-by-step explanation:
Early methods of pain control included a variety of approaches, such as the use of opium, attempts to scare off demons, and the use of roots, berries, and seeds. Opium, extracted from the opium poppy, has a long history of being used to dull pain and induce a sense of wellbeing. The practice of using natural substances for medicinal purposes, also known as ethnopharmacology, continues to influence modern medicine. For instance, compounds from the venom of a Brazilian viper (Bothrops jararaca) are used to lower blood pressure in medical settings, similar to their natural effect on prey. Opioids, derived from opium, like morphine and codeine, are used to manage pain, with morphine being used before and after surgical procedures to alleviate severe pain while codeine is often prescribed for mild to moderate pain. These opioids act on specific receptors in the brain and spinal cord to change the experience of pain. Additionally, other psychoactive drugs such as halothane and ketamine can serve as general anesthetics, blocking pain and inducing unconsciousness during surgeries.