How Your Muscles Work

MEDICAL ANIMATION TRANSCRIPT: Skeletal muscles are voluntary, controlled consciously by the nervous system, and are made up of fascicles, which are bundles of muscle fibers surrounded by connective tissue, blood vessels, and nerves. Motor nerve axons supply one or more skeletal muscle fibers, constituting a motor unit. Inside a muscle fiber, thread-like structures called myofibrils are organized into contractile units, or sarcomeres, reflecting the striations characteristic of skeletal muscle. Each sarcomere is made up of thick and thin myofilaments, strands of proteins called myosin and actin. Myosin forms thick filaments. Actin forms thin filaments. The protruding heads of myosin filaments form cross bridges that bind to actin filaments and ATP, an energy transport molecule. Thin filaments contain a sequence of actin molecules with myosin-binding sites. At rest, actin molecules bind tropomyosin and troponin, two contractile proteins that inhibit contraction. Skeletal muscle contraction begins at the muscle fibers' plasma membrane, or sarcolemma, with invaginations called transverse or T-tubules that surround each myofibril, and open to the extracellular space. T-tubules connect to a membranous network called the sarcoplasmic reticulum that store calcium and transfer ions via voltage-gated channels into the myofibril sarcoplasm to regulate muscle contraction. In the first step of muscle contraction, called excitation, a motor nerve fires an impulse, or action potential, across the neuromuscular junction, depolarizing the sarcolemma, and generating an action potential that spreads through the sarcolemma into the T-tubules, and excites the muscle fiber. The second step is coupling, wherein the action potential depolarizes the T-tubules. Channels in the sarcoplasmic reticulum release calcium into the sarcoplasm. Along the myofilaments, troponin binds calcium and separates from tropomyosin. In the third step, called contraction, tropomyosin shifts away from actin to expose the myosin-binding sites, enabling myosin to bind to actin, resulting in the activation of ATP and the cross bridges. Released energy causes the myosin heads to rotate and pull the thin filaments inward, sliding past the thick filaments and shortening the sarcomere. The fourth step of muscle contraction is relaxation, in which calcium ions return to the sarcoplasmic reticulum and break the myosin-actin bonds. The cross bridges disengage, and the sarcomere lengthens, resulting in relaxation of the muscle and the end of the contraction. ♪ [music] ♪
#MuscleContraction #muscles #physiology
ANM11013

[@monke_kekw5173]

It's amazing how all of this happens within a fraction of a second

[@caseykellogg707]

After scanning through several videos for over an hour, this is the most concise, accurate video on this subject I could find. No filler. No irritating personality to sit through. Great animation. Clear and understandable(as much as comprehensible), direct information.

[@nucleusmedicalmedia]

Glad it was helpful!

[@Canopiee]

Me in school: ugh, why do we have to learn about this topic ten years in a row?
Me when NMM uploads a video of the same topic: I’ll watch this a hundred times!

[@E..co_feel]

I am a student studying Biology...even if I study muscle function in model lesson, it is a great value to be able to see such things in animation...I find valuable videos from this almost every day...thank you very much Nucleus medical media ❤❤

[@Trepans.]

I always wanted to know how my meat strings work

[@ShahKashem]

Thank this man for skinning all his skin off to teach us this

[@iankrit]

Very detailed explanation and makes us understand our own muscles

[@srishtisharma3812]

I am neet aspirant.... This is so helpful

[@o.t.klegit7721]

Thanks a lot it was really helpful since i was studying the same topic yesterday and it just made my understanding smooth

[@nicoleashleydelapena3587]

The best visual animation!!

[@rohityadav9386]

Thanks Nucleus to giving this intresting and knowledgeable video.

[@shadowfax8434]

Everyone has a plumbus in their home. First they take the dinglepop, and they smooth it out with a bunch of schleem. The schleem is then repurposed for later batches. They take the dinglebop and push it through the krumbo, where the fleeb is rubbed against it.

[@MidniteAdventures]

Thanks for this!

[@dannyrichards-nb9sh]

Thx 4 sharing. Plz make alot more like this.

[@m_m786]

Helpful 👍 thanks for sharing

[@okiok2535]

Amazing !!
Human body is just 🤯🤯🤯

[@kabitakumari675]

Thank you for the video

[@AintPopular]

nice info keep em coming

[@Xeonerable]

I knew obviously that muscle worked via fibers tension, but I didn't actually know to this level of depth this is really how it works. Its crazy to think how fast this action happens and happens for ANY little movement we do with our bodies. I've never been crazy for biology but these animations and explanations spark my curiosity.

[@langeveldy]

Impressive evidence for the existence of the One who designed and made the intricate system of our muscles.

[@Kalumba_Jnr]

Great video 👍💯

[@user-gg3cw8sn8o]

Could you please upload a video of translation of proteins.
I am badly waiting for it because I love your videos

[@attiabatool1511]

Great ❤

[@setusworld]

Very nice

[@ShabanaBetageri-jv6ys]

Nice section I enjoy this section 🙏🙏💚💛💜💙💓💕💖💗💝💞💟👍👍

[@burakkorkmazgungor4884]

Nice ❤

[@worldhealth86]

Nice

[@Tommyleini]

Can you do a video on immune privilege?

[@Selenium188]

Best

[@lauragadille3384]

Where was this when I was an A&P

[@miha-zc8fd]

I am an experimental 11th student and well... I think all these amazing things that happen in less than a second show the power of God.❤❤

[@sudeepadhikari4454]

Nucleus ❤ Medical Media ❤❤

[@doveclaw8498]

Nice time to do 10 pushups

[@venkatsai007]

I watched it, understood. Now I don't remember a thing!! Is this common? :)

[@__ARYAN__..]

NEET Aspirants 👇👍

[@mrrishiraj88]

👍💯🙏

[@waelfadlallah8939]

👍

[@ReiSomethin_]

👍

[@joker2100]

What mechanism removes the calcium ions in relaxation?

[@kjford587]

An enzyme (Ca2+ATPase) pumps them back into the sarcoplasmic reticulum. Tropomyosin them moves back to block the binding sites on the actin strands again.

[@joker2100]

@@kjford587 Thanks!

[@ShabanaBetageri-jv6ys]

Gugu

[@fredteixeira3604]

i am almost sure that we were projected by a superior being.

[@SudipKumarKoley.]

Bio lovers ❤️💖
👇

[@bio366geethasankar7]

🙏🙏🙏🙏🙏🙏

[@Blue-dog522]

🎉

[@mdshamsulalammomin9733]

Please make video on "Rabies".

[@fayyazkamal4799]

some people say there is no creator
I think every human bieng who has wisdom and can use it ,will say ,absolutely there is a creator
We are just discovering the beauties of his creation
We have to think again

[@ultramarine7602]

❤😊❤😊😊❤😊❤😊❤😊😊❤😊❤😊😊

[@manger_22]

hi

[@ultramarine7602]

下さい😊

[@maryannenaude2567]

God is creative! ❤😅

[@xJuhnFromAbovex777]

Soooo how does a muscle work? Lol

[@user-gr1lz9oe6l]

Please can you speak Arabic language

[@AliHaider-tl4ph]

Am Pakistan doctor neurologist

[@vshobst6280]

Languages in Hindi

[@ultramarine7602]

目👀なくて下さいますました、という彼我はするにするならばいいと😮

[@ultramarine7602]

時時期あやねのします🙇するにはできない日ほど。～Ⅴからもできます

[@ultramarine7602]

,.Hするにはできますかはする😢

[@augustinenayagam3840]

Most probably muscle shape gives handsome or pretty for both genders fetch them into advertisement posture for their earning a higher income . But, muscle inside skin doesn't give mind blowing as though exteriorly focusing with branded garments. If an invention is available in the market that a scan camera equipment capable to display their muscles coverage like this, how will be they handsome or pretty beyond their makeup!

[@ultramarine7602]

下さい😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊😊

[@ultramarine7602]

,という