Role of the sarcoplasmic reticulum in muscle cells | NCLEX-RN | Khan Academy

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The role of the sarcoplasmic reticulum in controlling calcium ion concentrations within the muscle cell. Created by Sal Khan.
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15 фев 2010

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Комментарии : 131

@FeelgoodInc212 10 лет назад

I'm a first year Medical student. I just want to thank you for these great videos that make the difficult things you read on the slide shows from school, seem so easy...

@iBuyBitcoin 7 лет назад

Davíð Jónsson nice lol so how was med school, did u graduate ?

@MrPridizzle 6 лет назад

ya, touche´how was med school? things going good? :)

@blessanprasad1606 6 лет назад

yea i wanna know too~

@martinajaya975 3 года назад

So? Did you graduate? How did it go?

@FeelgoodInc212 3 года назад

@@martinajaya975 Yes I did graduate 2 months ago :) - working full time as a doctor now.. best of luck to all of you!

@nina4711 8 лет назад

You are a life saver. I'm trying to squeeze 8 months worth of study into 3 days before my exam (bad idea kids never miss your classes/ lectures) and your videos are literally helping me power through my syllabus.

@odaluisa2943 7 лет назад

how did it go ? did you pass?

@nina4711 7 лет назад

omg this was a year ago haha. Yes I did pass now I'm revising for my exams next month. And I didn't follow my own advice and left everything till the last minute again lol

@zainabalradi2306 6 лет назад

HAHA Nina you are horrible just like me but this does not work in medical school :( I studied my ass off the last two weeks still can't keep up

@pistabacsi462 6 лет назад

how could you pass with 3 days of studying?

@madeleinereidy1302 6 лет назад

I hope I'm never your patient

@repentance1748 5 лет назад

when we die and meet god, Ill make sure to say something nice about you. Thank you

@MassimoMD 5 лет назад

My physiology professor spent two weeks on muscle contraction. I never understood it, and two ~10 minute videos made it SO much clearer. Thank you.

@Rhibbler022 13 лет назад

You have just saved me from a cell bio teacher with a thick German accent and no understanding of how to explain concepts or teach. Kudos to you, my fine fellow.

@xHaniffax 11 лет назад

Can I just say that I actually love you. You are genuinely saving lives with these videos that are so fantastically explained and illustrated. Thank you.

@mosam4 8 лет назад

Can't express how much this video has helped me! I might actually do decent in my first year :') thank you!

@hamie7 12 лет назад

I read my books and its all just word floating round my head! Then I watch these vids and they all settle in place! Its like I can actually here them clicking in to place!ha Thanks so much you're doing a great job!

@jolopez9501 6 лет назад

I finally understand this concept. Thank you!

@TheTamtamm1 13 лет назад

this is amazing...nothing in my textbook or on the internet explained what exactly the sacroplasmic reticulum is for. Beautiful explanation, you just helped me get 20 points on my final! :)

@hoarski 11 лет назад

I learnt more in this series about the neuromuscular system in 30 minutes than my 4 hour graduate level exercise physiology class. You are a genius Sal.

@03rsfdance 6 лет назад

Sitting in Starbucks studying for my Animal physiology test on Monday and I go “ahhhhh!” Really loudly because I finally get how the Ca2+ gets into SR

@sabrinagerges6412 4 года назад

Super helpful! You should remake this video with the new findings about these structures and processes (e.g. ryanodine as a receptor to stimulate calcium ion release).

@nadiacharafi8815 5 лет назад

great video but I think its time now to update the information of the mystery box is actually called triad complex composed of dihydropyridine receptors (DHPR) voltage sensing channels of the T-tubule and the sarcoplasmic reticulum calcium channels ryanodine receptors (RyR)

@qwert173qwert 11 лет назад

most effective use of paint i've ever seen.

@therealDannyVasquez 6 лет назад

He's good, isn't he? I was very impressed with his quick illustrations and swapping out colors like a pro. Mad skills.

@LuckyHamster819 8 лет назад

This video helped me a lot in my studies! Thank you SO much!

@MikeB-sp6gp 2 года назад

Beautiful-- Clear-- Explanation. Thank you.

@sacc7734 12 лет назад

This video indirectly answered my question about how malignant hyperthermia works. Strong work.

@aaccinelli 11 лет назад

YOU'RE BRILLIANT!! Thank you thank you!!

@213151315131514 6 лет назад

This just solved a question I've been confusing for weeks !!

@tasadayl 8 лет назад

now that we have a better understanding of the mystery box can someone do a follow-up video explaining it?

@witsnap 13 лет назад

Thank you thank you. This really pulled it all together for me.

@Ph0be 10 лет назад

I love you Kahn, you're doing gods work.

@ohioSPIRIT 13 лет назад

GREAT job explaining. Keep it up- you're helping a lot of people.

@lawyerdoctor 7 лет назад

Great video. Thank you for the explanation and the enthusiasm.

@hould6611 13 лет назад

For those curious: The "mystery box" is now understood to be a co-op of two proteins. The 1st, bound to the t-tubule, is called a "DHP-receptor". It is a modified version of a Ca2+ voltage gated channel, altered to serve as a volt-meter. Ryanodine, the 2nd protein, is embedded in the SR. As an action potential moves into the t-tubule, charged amino acids in the DHP receptor signal the ryanodine receptor, itself changing shape to allow Ca2+ ions to flow into the cytosol, then to the troponin.

@dumar88 10 лет назад

Awesome explanation! Thank you!

@zipperteedee 6 лет назад

I also LOVE YOU !!!! What knowledge you - you're so comfortable explaining the most complex things in the most clearest way :) - you make biology and biochem good fun

@kristinapayne6854 11 лет назад

This is amazing.. You helped me so much with the diagram of sarcoplasmic reticulum

@ledionroci1502 4 года назад

You are absolutely incredible. Thank you 🙏

@Moemenk 6 лет назад

You're the man! BTW As stated in the comments below learned that ryanodine communicates with DHP (Dihydropyridine ) receptors (the big question mark in the video). Easy for me to say 8 years later

@esteebabe1 13 лет назад

thanks million times,u save my misunderstood lecture.God bless u,

@shannonsmith5623 Год назад

This helps understand the protein complex aspect of the muscle cell a little better. I am still trying to understand the terminal cisternae of the SR in more depth and their receptors that push against each other and excite each other to release the stored calcium ions.

@guzelkizz06 10 лет назад

Your videos have the same subjects as my lessons! I'm studying medicine, and this stuff is amazing!!

@03rsfdance 6 лет назад

Selin B. How is your studying going now? I’m a potential studier lol

@pbyrne72 12 лет назад

Wow. Great explanation. They say the mark of great intelligence is the ability to explain highly complex subject matter in a very simple, concise, and easily relatable manner. You sir, are an intelligent man.

@RodneyMarquezFishingChannel 8 лет назад

Awesome video. Very informative .-therapist

@SoulReviving786 3 года назад

I am a MBBS first year student... And I'm still taking help from khan academy ❤❤❤❤

@Fatima-rs3ew 3 года назад

thank you so much you make it so easy

@Arham1716 8 месяцев назад

Thank u so much Sal...Love ur videos ❤❤

@riyabhatiya2571 6 лет назад

Just perfect anything cant be better than a perfect concept.

@ranahanna160 7 лет назад

AMAZINGLY CLEAR

@weiwei4366 7 лет назад

Thank you, you are a fantastic teacher :))

@princetamrac1180 4 года назад

Amazing and easy explanation thx man

@myriad909 10 лет назад

Great lecture Khan! Just a small correction. When referring to the "mystery box," you mentioned the possibility that "ryanodine" may be involved. I believe you meant to say ryanodine receptor. The ryanodine receptor is a selective calcium channel which operates via a process known as calcium induced calcium release. Ryanodine, on the other hand, is a plank alkaloid and a high affinity binding partner of the ryanodine receptor and is able to inhibit or activate this calcium channel (depending on the concentration). Ryanodine receptors are prevalent throughout skeletal and cardiac muscle and are crucial in the physiologic processes you're describing here. Great work!

@MadelMac 10 лет назад

Agreed! Just went over this in lecture, and apparently the Ryanodine receptor acts much like the calcium channel of the pre-synaptic neuron in that it is stimulated by the sodium from the action potential carried across the t-tubule. This channel then opens up and releases calcium which stimulates calcium channels on the sarcoplasmic reticulum to open up and release even more calcium to the surrounding muscle myofibrils. According to our 2007 textbook that is! This protein bridge could be an even more recent discovery

@myriad909 10 лет назад

MadelMac Good point! To be completely accurate, ryanodine receptors (RyR-; located on the SR) are indirectly activated by sodium. The RyR is a prototypic Ca2+ induced Ca2+ release channel, which means that the most potent activator of RyR Ca2+ channel is Ca2+ itself. Other direct activators include the second messenger cyclic ADP ribose (cADPR).

@haddadelizabeth 10 лет назад

wowowow thank you. you're a lifesaver.

@superGoodjuju 13 лет назад

you are a fabulous teacher! I never once got lost (as I have in many other videos) and your voice is great:)

@user-ip8no6yj4n 3 года назад

Great... Thank you.. really great

@Vytagus 10 лет назад

I like how you make all this stuff easy to understand, by the way can you make oremvideos regarding human anatomy

@kevluv93 11 лет назад

You saved my ass. Oh my God, you are the savior of the common student!

@sgtOOX 14 лет назад

excellent. now if you are so inclined, time for some genetics and microbiology, and organic chemistry :( these videos are great for review though an excellent complimentary source for the curriculum. i will probably be using the calculus videos next semester for a refresher and physics as well to keep my edge. thanks again splendid job as always.

@virupannamedikinal Год назад

Thank you so much Sal Sir

@MrPridizzle 6 лет назад

Sounds good mate, see you in the next video :) Cheers!

@RockyBalboa211 14 лет назад

Yeah this is skeletal muscle, people sometimes get confused.. yet, just remember smooth muscle and striated muscle (Skeletal muscle and Cardiac muscle)! :D

@TravisGriffinTron 4 года назад

I suppose we all need heroes nerded out about certain topics. Everyone who watches this video will be happy to know that in the case of Saroplasmic roles, it's not me.

@FarrahGreye 13 лет назад

youre the greatest man on the earth

@robertadams2453 3 года назад

The "mystery box" is related to DHP and Ryanodine Receptor.

@chicharitoo22 10 лет назад

Awesome ! Love you

@BenjamindeVries528 12 лет назад

i was watching this in the living room. There was kind of an argument going on. When you raised your voice when you said sarcoplasmic reticulum it suddenly got quiet in the room. :] It was a really funny moment

@Emmadril 5 лет назад

Omg he’s so excited LOL

@Halahmed12 11 лет назад

I love you man. you're the best.

@iazahussainzz 3 года назад

learning this for my exams at the beginning of second year as we didn't have first year exams due to covid 19. ask me how im doing in 5 years :)

@MrAdamchadima 12 лет назад

You make us all geniuses !! Thumbs up ;)

@theladysilverwings 11 лет назад

YOURE A LEGEND

@wild.Petals79 11 лет назад

You have a good handwriting and very artistic as well

@leahevelee 11 месяцев назад

thank you❤

@bazilamir505 8 лет назад

keep up d good work

@mahamkamal6190 3 года назад

Masha Allah...

@lailamohd9267 6 лет назад

I'm confused on what is the purpose of T tubuls, please help

@mustavogaia2655 6 лет назад

God watching this video: "No way I could design that, man."

@6o4sage 7 лет назад

What happens to the calcium after its pumped back into the SR? Is it re used over and over again for muscle contraction? How many times can the same calcium ions be reused? Are they eventually metabolized and replaced by more calcium ions from the extracellular fluid???

@MMM-np4oo 8 лет назад

WOW 👍👍

@hould6611 13 лет назад

you're videos are GREAT btw! I apologize for being terse on my previous post. There's a word limit!

@cecillereloj867 8 лет назад

Wait, the mystery box ISN'T DHP and ryanodine receptors?

@alex-nv8rk 8 лет назад

+cez reloj It is! The video is from 2010, so the research at that time hasn't discovered that yet. Dihydropyridine receptors senses the electrical signals, which then trigger the opening of Ryanodine receptors, which in turn release Ca2+ across all the membrane of SR.

@phani991 8 лет назад

+Alexandr Pulbere I have an interview next week on the same topic, if you know can you suggest a couple of reviews on this topic..? Its all very new to me, cheers

@dr.hibayousuf7840 3 года назад

So what will be the voltage here?

@clarisse4610 4 года назад

What happens if the calcium was not return back into the sarcoplasmic reticulum?

@jennifergwishiri8326 6 лет назад

Anyone know what happens if the the DHPR is not activated

@Stelnice 3 года назад

Do you need ATP to pump Calcium ions out of the sarcoplasmic reticulum? :)

@desp0ina17 13 лет назад

@hould6611 Could you please make it more clear for me.. It might not get more simple than this but could you please try? I have exams in 3 weeks so it would be perfect if I add something that I didnt hear from the lectures.. I just lost it a bit after the second protein.. The second protein is replacing what??? Thank you for your help!:)

@renamicheletti8613 3 года назад

My teacher don’t even explain. Am learning what I paid For🤦🏻‍♀️🤦🏻‍♀️

@tyleromalley9333 8 лет назад

So can you do a bicep curl without any utilization of the tricep

@dontaye6558 5 лет назад

All your muscles are slightly flexed for the most part you arent using triceps when bicep curling

@simplyyjhez 3 года назад

for flexion (actually curling part)-no, but for extension (lowering of your arm to relax and begin the next curl), yes.

@xlongwu 11 лет назад

I love you too :)

@apes882003 12 лет назад

Im sure the mystery box is a ryanodine receptor

@hazemelnahrawy2715 8 лет назад

greaaaaaaaaaaaaaaaaaaat

@xtine19 10 лет назад

is the cytoplasm the same term used for sarcoplasm?

@Arsh.99 8 лет назад

yeah its the same thing just that it is for the muscle so its sarcoplasm

@amandaphung8056 3 года назад

I'm enrolled in an Anatomy course at community college with a crappy professor who links to your videos instead of making her own lectures. I love your vids, but I would much rather give you my money than the college.

@soccerg20101 10 лет назад

don't muscle cell's only have voltage gated Ca2+ channels?

@denominator94 9 лет назад

Noor J no

@bballev2 9 лет назад

dom rolfe your wrong. there are Voltage gated ca channels - im pretty sure thats what activate the ryanodine receptors

@bballev2 9 лет назад

Ev Mannion dihydroperidine receptors are the voltage gated ca receptros Noor J was asking about. had to look that up, but makes sense - they are the target of DHP ca channel blockers on smooth muscle :P fucker

@denominator94 9 лет назад

Ev Mannion No, your wrong

@bballev2 9 лет назад

ya ya. get some references or explanations to back up your Nos