Structure & function of skeletal MUSCLES: Myofibrils, sarcomere, sliding filament theory.

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Күн бұрын

Learn the structure of a myofibril and sarcomere, including the different bands and zones (I,A H and Z) and how these change when a muscle contracts.
I describe the sliding filament theory and go through the differences between slow and fast-twitch muscles.
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Пікірлер: 49

@Lorenzo-nf3dk 3 жыл бұрын

imagine they just made all this shit up

@daaniyalahmad8628 3 жыл бұрын

They did it’s all cap just to brainwash us

@dylanashton-lewis8624 5 ай бұрын

its called a theory so we dont actually know

@buffybbyxx 5 ай бұрын

Literally

@sidra7771 4 ай бұрын

this is so funny after dying about trying to force myself to learn the concept and what's going on this is the first thing I see😭 felt like an intrusive thought

@abdurrahmannarma5306 4 ай бұрын

😂😂

@bowww4226 Жыл бұрын

first year medicine student coming back to your videos to revise my first semester since the level of detail is still so helpful and relevant thankyou miss estruch i'm your biggest fan fr

@MissEstruchBiology Жыл бұрын

oh wow!! I love that the videos are helping you at university too, and for Medicine!!

@ajtv6208 2 ай бұрын

Muscles was the reason I got a C last year, only topic I left out and it was all over the paper3, learning it this time around lol, thank you

@oliviaodonnell2665 26 күн бұрын

2023 paper?

@sakeenarajpal1884 3 жыл бұрын

Thank you, thank you, thank you!! Your videos are amazing and have been such a help!

@MissEstruchBiology 3 жыл бұрын

Thank you Sakeena , so pleased to hear they are helping you out

@triciahardman5867 5 ай бұрын

Thank you SO much for all of your fabulous videos. I use them in my tutoring, especially when I'm teaching online.

@MissEstruchBiology 5 ай бұрын

ah thank you!! I am so pleased they help you and your students

@ShadreckKalonga 2 ай бұрын

Thanks you have helped me so much

@Jonboyr700 3 жыл бұрын

Thank you, thank you, thank you as well. I've watched so many videos and couldn't find any info on the ATPase that you went into. That connected a lot of dots for me. Also, this is the best presentation of the power stroke as well as the picture at the end of the the bands and zones. Thanks so much for this video!

@MissEstruchBiology 3 жыл бұрын

Hello 😀 Thank you! That is really kind of you. Really pleased to here you found the level of detail you were after in this video. Fingers crossed it helps you with your studies :D

@Jonboyr700 3 жыл бұрын

@@MissEstruchBiology I have a follow-up question for you, if you're able to answer it. If you suffer a muscle cramp, is this because there isn't calcium available in that muscle belly area, meaning the cross bridges are retained since there isn't ATP to release them? Definitely outside the scope of the video, but having a hard time finding a definitive answer. Looking to get the books on your list to help withy future studies. Thanks again for this great presentation and I subbed your channel

@hawadoh Жыл бұрын

@@Jonboyr700 Muscle cramps can have various causes, but one possible explanation is related to the role of calcium ions in muscle contraction. During muscle contraction, calcium ions are released and bind to troponin, allowing myosin cross-bridges to interact with actin filaments and generate force. When the muscle relaxes, calcium ions are pumped back into the sarcoplasmic reticulum, allowing myosin cross-bridges to release and the muscle to return to its resting state. If there is a disruption in the balance of ions, including calcium ions, in the muscle cell, this can affect the muscle's ability to contract and relax properly, leading to sustained muscle contraction and a cramp. However, other factors can also contribute to muscle cramps, including dehydration, electrolyte imbalances, and muscle fatigue, and there may be other mechanisms involved that are not related to calcium ion availability.

@Jonboyr700 Жыл бұрын

@@hawadoh Brilliant. Great response and thanks for the insight.

@chituwanankamba8883 3 жыл бұрын

Great Video!

@MissEstruchBiology 3 жыл бұрын

Glad you liked it ☺ thank you

@bellastarmartin4601 Жыл бұрын

Hi Miss, Good evening. Is everything on your PowerPoint slides all that I need to know for this lesson? I have a topic test tomorrow and my teacher was not in on Monday so I haven't been able to learn anything about Muscles(only see on once on Monday and once on Thursday for this week).So I'm trying my best to finish making these notes then revising.

@fatima-de8gv 2 жыл бұрын

hiii this video helped loads, one question, u said that the sliding filament theory stops when the actin cannot move closer together, what does this mean, move together how?

@yoshikagekira3615 2 жыл бұрын

Great video, thanks for uploading! I understood the vast majority of the material covered in this video. One detail that is kind of unclear to me is why there is a high glycogen store specifically in fast twitch muscles? I understand that the glycogen will be converted into glucose and then converted into ATP but since both aerobic and anaerobic respiration will require ATP shouldn't there be a high concentration of glycogen in both types of muscle?

@MissEstruchBiology 2 жыл бұрын

Hey, great question. Yes they both use glucose, but you cannot respire anaerobically for long due lactic acid build up. So a continuous supply of glucose from glycogen would not be required.. Hope that helps 😊

@yoshikagekira3615 2 жыл бұрын

@@MissEstruchBiology Oh, I see! So the supply of glucose from glycogen is only used for anaerobic respiration?

@leia__xd9485 Жыл бұрын

Ahh thank you for asking, i had the same question lol (also i love ur name 😉 🤚 )

@olpp1757 3 жыл бұрын

Hey, the CGP guide says that ATP is used to move the myosin head, causing contraction. Why is this different? Thank you so much :)

@MissEstruchBiology 3 жыл бұрын

hello 😊, that's true and the same as what I've said, only the statement is simplified and doesn't give the exact role of ATP.

@juliaonyebuchi6592 3 жыл бұрын

Is it correct to say just the I and A band as I got taught they were called the isotropic band and the anisotropic band, but is saying it short hand (I &A) fine in the AQA bio exams?

@MissEstruchBiology 3 жыл бұрын

Hello, If you are AQA then yes, I and A band is all that is expected for the exam. You do not need the full names for the exam.

@AG-ql1sy 2 жыл бұрын

Up to now I’ve understood everything for topic 6 but this started to confuse me... the whole ATP and ADP thing was confusing

@ummaig9442 Жыл бұрын

Hi, I’m a bit confused as to why fast twitch fibres have a higher glycogen storage? What does this do, can you please explain ! X 18:14

@GhostHawk272 Жыл бұрын

Glucose is stored as glycogen in mammals, so I imagine that the higher glycogen storage would allow for more glucose to be formed in really high amounts when the glycogen is broken down. This increased availability of glucose would allow more respiration to occur to form more ATP. More ATP available means that those short-lasting and powerful contractions associated with fast twitch fibres can occur more readily.

@uwotm8770 2 жыл бұрын

Hi miss, why do fast twitch fibres fatigue more quickly? Thank youuuu

@MissEstruchBiology 2 жыл бұрын

As they don't receive as plentiful an oxygen supply so respire anaerobically creating the lactic acid which causes the muscle fatigue

@adhamahmed2819 3 жыл бұрын

Is the myofibrils one large strand of cell or is the Myofibrils made up of lots of small muscle cells which are collectively called a myofibril?

@MissEstruchBiology 3 жыл бұрын

Hey, Myofibrils are protein based organelles found in muscle cells. Hope that helps 😊

@sabaaalkadi8667 3 жыл бұрын

How does the H zone which is only myosin shortens , and then the A band which is myosin length and actin stays the same?

@MissEstruchBiology 3 жыл бұрын

the H zone is the section where it is just myosin by itself, but it isn't the full length of the myosin. When the actin filaments slide closer together this decreases the section (H zone) where it is just myosin. I hope that helps