How a muscle contraction is signalled - Animation

[Equistta]

I get the picture of contraction with one sarcomere, but if the Z line if pulled forward of that one sarcomere, doesn't that pull the thin filaments away from the thick filaments in another sarcomere (which inhibits contraction)?

[JanelleHernandez]

thank you! this is really clear and concise! really appreciate it!

[beautyistoxxic]

effff physiology. it will be the death of me.

[apalmer12]

Y U talk so fast?!?

[MsPelicanus]

@apalmer12 yes i know she sounds like she has a timer on !

[louloulelle]

anyone else that has a test tomorrow?

[MrSinceIdonthaveyou]

@SweetGuy

YEah.. Glad it worked for you also..

that site

MusclesMaximizer.info

provides scientific nutrition about

how you can get the body u've

always wanted.. I was once a

skinny guy here but when I took

a bit on it, I was happy to have

a muscle like this..:))

[LucifersCounterpart]

woow i tried my best to understand this but now u made it so simple thank you so much. Now me and the physiology can rest in peace :D

[InnateWhisper]

By far the best video for this explanation, IMO.

[zestysafari]

This rocks ~ got my zoology exam in 2 hrs and now I feel better

[arajaram19]

Thanks babe

[MegaMasturbator]

Hahah it took that much body work to just click play! Wow the human body truly is amazing!

[shadowstrider43]

Ah, wonderful Anatomy test prep. >.<

[AdamArchangel]

Doesn't really go into the role of ATP in the "head" of the myosin filaments, but a good overview of the process =]

[iosaturnalia]

PURE GOLD

[laurenxprice]

She talks way too fast!

[mammalicious82]

why are we even given textbooks these days, all information should be supplied via the internet, so much easier to absorb!!

[frankpiay]

awesome!!

[GixxxerKim]

Isn't this :55 sliding filament theory a THEORY? Still unknown exactly how contractions occur?

[shea333]

@GixxxerKim A theory is something that is widely tested and is excepted by the overwhelming majority of scientists. If we didn't know how this worked it wouldn't be called a theory, it would be called an idea or hypothesis. You are misrepresenting the word theory.

[GixxxerKim]

@shea333 I appreciate the response, but theory is exactly what I meant. Its widely accepted by scientists, just like theories of flight, and creation of the universe. We still don't KNOW how it works, but widely accepted ideas (as you say theories) are what we have. It is still called a theory in recent fitness books, and I think rightly so. Its the best we have right now, so its what we go with. Peace.

[shea333]

@GixxxerKim Scientists try to give a non-bias, objective representation on the nature of any one thing. Theories are supported by evidence, hypothesis are not, they are derived from evidence. Evidence is all you can ask for when looking for something that is true. There is nothing that is a scientific claim that is full proof, if there were such a thing we wouldn't need evidence. Based on what you say about theory, there isn't any one thing you could represent to be understood in this world.

[GixxxerKim]

@shea333 whatever.

[shea333]

@GixxxerKim I'm not trying to upset you I just like discusion and I just happened to disagree with your idea of theory.

[JasonGWolfe]

Great Video. Very helpful for studying ex phys.

[RoseannaLevermore1]

I thought sodium was released into the T tubles? and calcium by sarcoplasmic reticulum?

[stuartg40]

Very good animation. After watching just a few times I now completely comprehend this complex mechanism. Well put together.

[08dressageGal]

UGH that was explained to fast!!! This helps though

[litojonny]

I FUCKING HATEEEEEE MUSCLE CONTRACTION

[kukiimonzter]

Ahh you just saved me from failing my test:) jaja thats what i get for sleeping in class lol thanks so much :D

[waakkeuppp]

great job.

[ryu144]

clear and concise explanation without sidetracked detail. Perfect.

[justikeraulu]

now i understand!!! thank you!!!!!!

[katakaka1z]

Awesome :D

Many Thanks =]

[Killane1701]

Ap in t-tubule----->aktivation of dihidropyridine receptors------->aktivation of connected ryanodine (ca2+ release channels) receptors in the terminal cicsternae (leads to activation of adjacent channels as well)------->calcium released into the cytosol right?

[InnateWhisper]

THANK YOU

[Pangjunmin]

dang, this is better than my professor

[knightro08]

BEAST!...great clarification!

[PaulPenalver]

cleared it up better than my teacher :D

[susie489]

i luv it yeaaaa!!! thanks uploader :)) books are creepy, internet rocks ;)

[hailo666]

Thanks so much, it REALLY helped! I thought I was screwed because of my crap biology teacher... well youtube can be my teacher!

[bluejello007]

Ahh yes. A 1 hour lecture condensed into a 2 minute video. An excellent reason to smile today.

[Haley974]

ooooooooooooooooohhhh

[RestlessSauron]

By watching those videos you need no textbooks!!!

[4826jarontheman]

This is a very well put together video. Thanks for the upload.

[113dawaween]

I really appreciate it, thanks a lot

That was a great piece of hard working

Best of luck :)

[MrTheCaramelito]

that was usefull

[deyaaliaga]

THANK YOU.

[cuteamyn]

allah is great!

[bustthewave]

I may actually pass my musle test for A&P... thanks for the upload :)

[Shrubbs]

Great animation and explanation!

[freyajean]

0:30

[freyajean]

anatomy and phisiology 101

[freyajean]

@freyajean it was 1980 sumthin

[freyajean]

0:40 ?

[swissmissdesigner]

we can dump theses expensive  textbooks and just watch youtube for free!

[elguvni]

@swissmissdesigner if u think so ur an idiot and u will fail in life if u dont read books and just watch yt vids. these should only be for revision as they have lots of missing features

[peruvianchaz]

ahh this is too basic!

[PrincessNafi]

thank youuuuu!

[sebthehardrocker91]

Thank youu!! haha better than whats on the guyton book

[malubayraymond]

all this mechanism in a fraction of a second... what a genius machinery created by God. :D

[mattkin123]

@malubayraymond Evolution.

[malubayraymond]

@mattkin123 yes, evolution. but i believe there is Someone responsible for that phenomenon.

[Killzoneguy117]

@malubayraymond Morgan Freeman

[yourhellloud]

im learning this in year 12 human biology.. thank goodness for this video:):) thankyou!!!

[mmlist831]

all i know is when i was in labor it fuckin' hurt!

[chiemo]

Thank yOu very much for this video lesson..... F*** guyton physiology book..so hard to understand

[ZyGaming]

My biology exam is in a few days...heh

FML.

[kooziejr]

so easy but the fuck am i going to remmebr this and the 10 billion other things for my final?

[allewis86]

@kooziejr haha i'm with you on that one!

[kooziejr]

@allewis86 you have no idea!!! lol... so much fuck fuck fuck

[fishakimbo]

you've saved my life - my book was not this exciting ^__^

thanks for posting this!!

[MoByGh]

sweeeet dude!

[jamutta]

Thank you for the video. My teachers sometimes makes a powerpoint presentation with similar videos.This makes everything way more easy then a dry biology book.

[Taser15]

Last minute cramming for the AP Bio :D

[MrBumfun3]

this has really helped me with this part of my A-level course, thank you

[LabRat010]

Taking the AP Bio exam in a few weeks. This helped enormously...it's so intuitive. I really appreciate this video.

[ekizone]

Why go to lectures ????

[Steveleone8686]

It's clear to me now. Don't have to worry about my test anymore. Thank you

[sarahstgo20]

perfect! now i get it lol

[yinyue168]

Thanks so much, this was exactly what I was looking for. Concise and completely understandable.

[TheFarah91]

this is the PERFECT video

[RealityrealitySeeker]

this rocks

[skifreak8]

how is it that my bio teacher spent 80 minutes failing at explaining this and i go on youtube and watch a 2 minute video 3 times and understand it??

[pandasoldier]

Amazing isn't it.  Some teachers just suck. I think the world needs to simplify everything like this.

[syrrinx]

shnnarrrcomereeeeee gimpy

[sohabsha]

hey thats wrong ca ion dosent attach to tropomyosin it attachs to troponin and to be specific troponin c

[tzoni69boy]

@sohabsha you're right!

[DemonicalSlayer]

God bless the internet !! And damn complicated physiology books!!

[vonkroppelberg]

@DemonicalSlayer hahaahgood one

[TheArvinian01]

@DemonicalSlayer lol, i agree but what's the source of the internet if there were no books?

...

[xbookoo2x]

Thanks :)

Big help since my anatomy professor is incompetent.

[theorganichispanic]

We are awesome, elegant, brilliant machines.

[vishalsohal1]

gr8!!!!!!!

[Shaggice]

I need some help people. What exactly is a sarcomere? is the aktin and myosin inside it?

[vishalsohal1]

@Shaggice its the smallest contracting unit

[syrrinx]

a sarcomere is the basic functional unit of a myofibril ;)

[ArizonaSean]

Damn, can they talk any faster?

[gerard141]

haha i know

[deelyee5]

this is really awesome!!!

[jamelut]

damn this is what i needed for my midterm..!! youtube really has everything!!

[PatVRulz]

Why and how does the calcium make it to the actin?

[rasaxSF]

Ca(2+) is stored and released by the sarcoplasmic reticulum after ACh is released from the synaptic vesicles through exocytosis, and the sarcolemma is depolarized. 

Hope that helps.

[rasaxSF]

Oh, and to answer the last part of the question: after the sarcolemma is depolarized, calcium binds to troponin. Tropomyosin then uncovers the binding sites on actin.

[foodmore]

diffusion down a concentration gradient my friend. thats why the calcium stores are in the SR. And troponinC has high bindind affinity for Ca2+

[lacusftw]

Excellent!

[BECK26x]

that was sexy

[swiissy]

quick, but awesomely explained

[jmschnerch]

thank you! very helpful.

[gemglass88]

clear and concise video. Thank you.

[rajbtor]

This must be clarified to be either the change events assoicated with skeletal muscle or cardiac mucle. Smooth muscle, in the GI for example, has different sequences.

They both rely on Calcium however, in smooth muscle the myosin light chain kinase is involved. The MLCK is phosphorylated, the light chains activate myosin enabiling to to undergo the cross-bridge myosin head-actin filament assoication.

Calcium helps form the calmodulin complex in smooth muscle.

A.B

Med Student

Canada

[GetUpYouLazyBear]

That is quite helpful. Thanks for posting.

[DaggerBiology]

Cytosol is the modern name for cytoplasm. Sarcoplasm (sarcosol) is a type of cytosol specific to sarcomeres(muscle cells).

I will clarify this in an update

[DaggerBiology]

Thanks to Rinkeshpatel1 for the correction...

Cytosol is the the aqueous solution of a cell's cytoplasm, consisting of water, organic molecules and inorganic ions

cytoplasm is the contents of a cell except for the nucleus. It includes cytosol, organelles, vesicles, and the cytoskeleton

Although they are used interchangeably in casual conversation, it is good to know the difference.

So... sarcosol is a type of cytosol sarcoplasm is a type of cytoplasm

[Fastlane51]

Well I would not call cytosol the modern name, because its referring to different things.

Cytosol is just the liquid portion of the cytoplasm; cytoplasm incorporates the entire contents within the cytosol including organelles.

[bronzedx1989]

its not cytosol its sarcoplasm

[philippmikio2]

impressive and helpful. Thank you