How exactly do muscles’ ability to apply force emerge from chemistry / physics. I “know” pretty vaguely that the elasticity of muscle tissue is fundamental to how it works, but how does the body actually chemically create that elasticity, and what phenomenon of chemistry is elasticity emergent from?
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The way it works is that each muscle cell physically contracts. It physically pulls itself together from the inside into a shorter shape, causing the overall muscle (made of many cells) to shorten and change its shape too, pulling any tendons and bones along with it.
(I’m honestly not entirely sure what you mean by elasticity. There’s multiple possibilities, I just don’t know which one you mean.)
So how does that contraction work?
How that works is, they’ve got a bunch of different filaments of protein inside of them, in two types, myosin and actin. These protein filaments ultimately [slide past one another](https://en.wikipedia.org/wiki/Sliding_filament_theory) in order to contract. What happens is that the mysoin head on the [myosin](https://en.wikipedia.org/wiki/Myosin) filament binds to the [actin](https://en.wikipedia.org/wiki/Actin) filament and sort of throws the actin filament past itself; since the filament is covered in these active myosin heads, this “concerted throwing” ultimately leads to the two filaments sliding past one another.
So how does that throwing past work?
How that works is, the [myosin head](https://en.wikipedia.org/wiki/Myosin_head) is activated and derives its energy from a compound called ATP that it [hydrolyzes](https://en.wikipedia.org/wiki/ATP_hydrolysis). ATP is an energy store in the body, and it has to physically bind to the myosin head. The binding changes the shape of the myosin head, but then the force of the unbinding changes the shape again, in an energetic way that can perform physical work.
Muscle cells have the biggest protein in the human body let’s goooo! That’s no small feat the muscle cells have a spring protein that are long! They’re being pulled by both ends. Ok so like a bunch of those right and you wrap them in this conductive thin little like burrito. Ok so what’s conductive and goes on burritos? Sodium! Bam you drop a few of those Na particles down an ion channel from the brain. Think of it like donkey cong in one of those cart levels and he’s an ion he’s donkey cong he’s all charged up and shit just traveling down the rail cart level just riding around. Eventuality from the brain you can ride the cart turn right at the spine all the way down town to the muscle BAM giant spring proteins activate!!!!!!!!!! Muscle contracts. Where did this sorcery energy come from?! Mother trucking potential energy, dog, the cell reactivates the spring.
Add a couple billion donkey cong and lots of glucose and some seemingly random things and that’s basically pretty much exactly what’s happening.
Donkey Kong 👑
Elasticity is classic…cal physics?
How much of the force is going to travel through the object and action reaction back. If you put the same amount of force throwing a bouncy ball and another ball with the same mass, the bouncy ball is going to accelerate more! Whaaaaaa, it’s because of the way the atoms jiggle, that’s really all there is to say about that. Muscles are elastic and can direct force while rebounding back in certain protein motor like mechanisms. To hear about elasticity from someone who doesn’t have tbi looke up hookes law, not elasticity law the business shmoosers have that copyrighted I guess.
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