How Does Caffeine Wake You Up?

When you get coffee jitters, caffeine has tricked your brain into anticipating danger. Lauren explains how it works. Learn more at HowStuffWorks.com: http://science.howstuffworks.com/caffeine.htm Share on Facebook: https://goo.gl/adWdyH Share on Twitter: https://goo.gl/IrlOYS Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com According to research from Johns Hopkins University, up to 90% of people in the United States habitually consume caffeine at doses that make it by far America’s most popular drug. A nd we’re not even the world leaders in coffee consumption per capita: I’m looking at you, Finland and The Netherlands. Caffeine is a natural compound found in plants like cacao, coffee, and tea, and researchers think that its perky properties have made it part of humanity’s diet since before the dawn of recorded history. So let’s take a look at why it’s so popular – by delving into the chemistry of the human body. Every cell in your body breaks down a biochemical called adenosine triphosphate, or ATP, to get the energy it needs to do stuff. Y’know, contract your muscles, transmit electrochemical signals in your brain, build new cells – that kind of thing. So when your cells do any kind of work, from helping you fight a bear to helping you read (and understand) a probably-harmless book that you found in the basement of a creepy cabin in the woods, those cells wind up excreting a few byproducts from the breakdown of ATP. One of them is a compound called adenosine. In the brain, adenosine is known to cause drowsiness. When it binds to specialized neural receptors that it fits into like a chemical key into a lock, adenosine slows down (aka inhibits) the activity of particular neurons. Those neurons happen to be in parts of the basal forebrain that control whether you’re awake or asleep. Adenosine makes those neurons fire less often, and less activity equals drowsy. Caffeine just happens to fit into the same receptors in the brain as adenosine -- sort of like a lock pick. So part of what’s happening when you drink coffee (or cola or whatever) is that less adenosine can reach those receptors. Furthermore, where adenosine slows down neural activity, caffeine speeds it up. Those neurons start firing more than usual. This extra activity leads to caffeine’s physical effects because our brains are dumb. One job that our hypothalamus has is to monitor for extra neural activity because that’s a sign of stress, or heightened arousal, or danger. Basically, your hypothalamus can’t tell the difference between an espresso and an attacking kaiju, so its response is the same either way. It signals your pituitary gland and your sympathetic nervous system that there’s an emergency, and that they’d better get the adrenal medulla to release some epinephrine, aka adrenaline. Adrenaline, of course, being the “fight-or-flight” hormone that puts your body on red alert. It makes your pupils dilate. Your airway opens up. Your heart beats faster and your blood pressure rises. Skin-surface blood vessels constrict to slow blood flow from potential cuts and increase flow to muscles. Your liver releases sugar into your bloodstream for extra energy. And your muscles tighten up, ready for action. In other words, you’re real awake. The half-life of caffeine in your body is about six hours. Meaning that if you drink a cup of coffee containing about 200 milligrams of caffeine at 3:00pm, you’ll still be left with about 100 milligrams by 9:00pm, and about 50 by 3:00am. Your brain may still be having trouble binding enough adenosine to really slow down. Thus keeping you awake – or at least, preventing deep, restful sleep. That’s one reason why experts recommend moderation when it comes to caffeine intake: Less than 300 milligrams per day, which equals about two cups of coffee. SOURCES: http://download.e-bookshelf.de/download/0000/0148/02/L-G-0000014802-0002347358.pdf http://www.hopkinsmedicine.org/psychiatry/research/bpru/docs/caffeine_dependence_fact_sheet.pdf http://www.theatlantic.com/business/archive/2014/01/here-are-the-countries-that-drink-the-most-coffee-the-us-isnt-in-the-top-10/283100/ http://www.caffeineinformer.com/caffeine-what-the-world-drinks https://www.erowid.org/chemicals/caffeine/caffeine_chemistry.shtml http://learn.genetics.utah.edu/content/cells/fight_flight/ http://www.hopkinsmedicine.org/healthlibrary/conditions/endocrinology/adrenal_glands_85,P00399/ http://www.sciencedaily.com/terms/sympathetic_nervous_system.htm http://science.howstuffworks.com/caffeine.htm/printable http://health.howstuffworks.com/wellness/diet-fitness/exercise/sports-physiology.htm/printable http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3599777/ http://www.wiley.com/college/psyc/westen240494/student/mod2/Sleeping.htm

Comments

niloufar hozouri: wow that was so informing! thank you for the good video.

Eric Morales: I chug a java monster every morning and they have 189mg caffine. the highest mg i could find. it lasts till about 3pm. just a little fyi.. she made an evil dead reference and a Pacific Rim reference. I like her. lol.

Nakamoto Cheyenne: my body must be messes up, because when I drink coffee I get tired....I use it to go to bed sometimes

Jonatan Eriksson: Cool Video !

Gülnur Hazal: Hahahahahahaha. :D 2 cups.... HAHAHAHAHAHAHAHAHAHAHAHAHAH

Asap Money: yes I do got a caffeine addiction I will drink 6 to 10 cups

h A x a g o n: cleavage pls :)

Emily Diaz: why doesnt caffine effect me? it doesnt make me tired or awake

Arthur Yancey: Hello Brain Stuff,
How does Focalin XR work and affects the human brain? I have a problem staying awake and focused during the day; so therefore my doctor increased my dosage to 35 mg and it still does not help. I can even take 200 mg of caffeine and still get super drowsy and week and wind up falling a sleep. If none of these stimulants are not working, what may be going on in my brain? When I get like this, I lose all cognitive thinking, memory, coordination, focus, and awareness.

TheNemesis: 2 cups of coffee? Bullshit. 270 cups of small coffees are okay. You gotta do whatever it takes to get those cups in, if not you're weak minded and not doing whatever it takes.

Aaron Pearl: My question is - why is it that the more coffee you drink, the less effective it is?

Jack Kenway: I don't know about you guys but caffeine never kept me from sleeping, anyway good video Lauren!

Robert Sundström: Coffee can during the right circumstances make you sleepy. I have twice tried to drink coffee before having gone to sleep after recommendation from a friend whose mother drinks it before sleeping. I have found it working very well. I am in fact drinking some right now and I'm feeling drowsy at 02:30 AM. My third attempt.

hakachukai: How does caffeine tolerance work?

After years of caffeine use the most people literally wouldn't believe, my caffeine tolerance is so high that I can straight chug a 2 liter of Mountain Dew and go to sleep no problem.

This video reminded me of two past caffeine stories:

#1: Drinking about 9 liters of Mountain Dew a day for a few months
#2: Washing down Viveran ( 100mg caffeine pills ) with Mega Jolt ( which is Jolt Cola with 50% more caffeine )

I don't recommend ANY of the above! That was almost 20 years ago and I'm still slowly discovering and dealing with the long term health effects.

Ironically... I never drank coffee. I can't stand the smell or taste of it! It's straight disgusting! X-P

b00034211: that last comment about vibrating through space time made me giggle

ssj4rebellion: Finallyyyyy I stumble upon an interesting and educational channel. Earned my subscription!

MauiSponge: lol. an attacking Kaiju . I love it! and i love your channel! Thanks Lauren for all the work you folks at Brainstuff do to keep us smart! ^_^

nystagmus: I see ty

Awe Galore: Caffeine apparently does not have an effect on me.

Eric: i love you guys

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