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Current time:0:00Total duration:3:18

Video transcript

even when you're resting your brain and body are hard at work maintaining stability in your internal environment it's a process called homeostasis it's how you maintain your temperature heartbeat metabolism all that even though external conditions changed and it's also a state your body strives for when you get out of balance you've experienced this before if you've ever been exercising then you get out of breath and really hot and sweaty and then afterwards your body cools you off and lowers your heart rate that's homeostasis at work and it also works when you take drugs so for example if you take amphetamines then which raise your heart rate then your body quickly tries to lower your heart rate and get you back to normal and what's really interesting is how smart your brain is about this if you're a regular drug user then you probably have certain ritualistic behaviors that lead up to the drugs and train your body for example you might always take your drugs in a certain location after eating or a certain time of day so let's say you're a cocaine addict and you're always in one particular room when you inject yourself with cocaine it's your preferred method of entry and it takes you a few minutes to set out your needle set up your space kind of get ready and after a few times doing this your brain starts to recognize that these external cues like the room the needles the the whole process of setting up means that your body is about to get a nice big dose of drugs so rather than wait for the cocaine to enter your body and then start regulate your normal functions your brain tells your body to get a head start it starts lowering your heart rate before you even take the drugs and that's why after a while your body needs a higher dose to reach the same high okay so imagine you start out at a certain level we'll call that homeostasis and when your brain knows that drugs are about to come it starts adjusting your bodily functions so it lowers your heart rate your metabolism etc and then it takes even more of those drugs to get up to your your high point but what would happen if you get all those cues but then you don't get the drug so your body's already pre adjusted preparing to get the stimulant but nothing comes to counteract the lower heart rate lower metabolism you would experience a crash because there is no high to counteract that slowing down that your brain has initiated okay so let's imagine the other side of it though that you're in a new location when you take drugs so your body doesn't have time to pre adjust but you take that same level of drugs and that's why a lot of people overdose when they take drugs in a new location because if their body doesn't know it's coming it doesn't pre adjust but they take the same high level of the drug then their body's not prepared for that amount and it causes an overdose