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007 What is an Action Potential

What is an Action Potential?

That’s the question I’m answering in todays Interactive Biology Episode. Watch the video above to find out ;)

This is the first in my new video format and I really hope you enjoy it.

Once you have finished watching the video, go ahead and leave your comments below.

If you have any questions, that would be the place to ask them.

- Leslie Samuel


Transcript Of Today’s Video

Welcome to another episode of Interactive Biology TV. My name is Leslie Samuel. In this video, I’m going to be answering one basic question: What is an action potential? You’re probably going to notice that it’s a little different than the 6 episodes that I’ve done before. And the 2 main differences that you’re going to notice are:

  1. I no longer call it BioVid. The reason for that is “Biovid” doesn’t really tell what this is all about. I’ve changed it to Interactive Biology TV, because it’s going to be interactive, it’s going to be about biology, and it’s going to be a video. So from now on, you’re going to hear me say “Interactive Biology TV” as opposed to “BioVid.”
  2. You’re going to notice that I’m on camera this time, and that’s a little different because in the past, I’ve done slides and animations and so on. The reason I’m making this change is basically because I wanted to do something that I can produce much quickly. In the last year, I only made 6 episodes, and I want to be doing episodes on a regular basis and this is just easier for me to produce and I can put together a relatively professional-quality video in a short period of time.

I hope you enjoy this new format. Please let me know in the comments below, and if you have questions or comments about it, you can just do that. It’s going to be relatively laid-back and I’m just going to be talking to you about these different concepts.

So, let’s get into the content for today. Today, I’m answering the question “What is an action potential?” If you’ve looked at any of the previous episodes, you’ve seen that I’ve given an introduction to the nervous system and to neurons. That introduction to neurons basically comes right before this in terms of understanding the concepts, the different parts of the neuron.

Now, the main part of the neuron that we’re going to be talking about today is the axon. I have a very amazing device here that I’m going to be using to illustrate that. The axon is the part that sends the signal. A signal starts in the soma, there’s processing that happens in the soma, and we’re going to talk about that later on. It sends a signal via the axon, to the ends of the axon, the axon terminals, and then that signal can basically go to the next neuron.

How I’m going to illustrate this is really simple. If someone touches your hand, you feel it. And the reason you feel it is because there are signals that start at that point, and the signals go to your spinal cord, and then up to your brain. These are electrical signals that happen relatively quickly, so that your brain can interpret that stimulation, and your brain tells you “Okay, someone is touching you.”

That is an action potential. You can call it an action potential, you can also call it a nerve impulse, but it’s basically that electrical signal that goes from that stimulation point all the way to the brain. And these signals are going on throughout the body, doing a bunch of different things, and we’re going to talk about that.

So, here we have my handy-dandy iPhone 4. I’m going to turn it on. And I have my earbuds, I’m going to put these on. I’m assuming you guys know how this works, but the iPhone 4 is an amazing device. It has built-in an iPod, and I’m going to assume you know what an iPod is. You know what, I’m going to tell you what an iPod is, just for some strange reason you don’t know what an that is. It’s an MP3 player that allows you to play music and audio books and a whole bunch of other stuff.

Anyhow, I’m going to stimulate this iPhone, and it’s going to send an electrical signal via this cable to the earbuds, and we’re going to assume as if it’s going to my brain. And it is going to my brain. So, here we have a cable sending signals, and then there can be a response. The brain can interpret that stimulation. Okay, so I’m going to press Play, and this is me stimulating. And as soon as I press Play, I can hear music. I can dance to the music, I can do a whole bunch of stuff. Let me stop that for now.

But basically, here we have that wire, and these are the axons of the neurons sending signals to the brain, to different parts of the body. It’s basically how the nervous system communicates with the different cells and organs and the glands. So, really simple, the action potential is that signal that goes through the axons along the nerves and basically takes a signal from one place to another place, whether that’s from the brain to my hand that pulls away, whether it’s from the stimulation point all the way to my brain.

I hope that makes sense for you. That’s basically what an action potential is. If you have any questions, comments, leave it below in the comments field. I’d be happy to follow up and answer your questions, or even make a video about it. That’s it for this episode, and I’ll see you on the next one.

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Leslie Samuel is the creator of Interactive Biology. His mission is to use this site to Make Biology fun for people all over the world.

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Leave An AWESOME Comment

240 Responses to “007 What is an Action Potential”

  1. Skhoury January 5, 2011 at 9:43 pm #

    Leslie

    I like the new format. It is very clear and interesting. Thanks for continuing to do this.

    Mr. Khoury

    • Leslie January 5, 2011 at 9:48 pm #

      Thanks for the Feedback Mr. Khoury. Glad you find it clear and interesting. I’ll be trying to post a video every weekday, so stay tuned!

  2. allison adams January 27, 2011 at 10:19 am #

    Great job!! Very easy to understand!

    • Leslie January 27, 2011 at 10:21 am #

      Thanks Allison. Glad it makes it easy for you to understand :D

  3. naqqiya April 13, 2011 at 4:56 am #

    loved your video, im very confused with compound action potential can you help me out with that

    • Leslie April 13, 2011 at 6:27 am #

      Hi Naqqiya.

      An action potential is what happens in an individual axon. Nerves are bundles of axons. In other words, there are MANY axons in one nerve. The compound action potential shows you the sum of all of the action potentials in all of the axons of that nerve. That being said, the more axons in the nerve that reach their threshold to result in an action potential, the bigger the resulting compound action potential. If all of the axons in that nerve are firing, you will have the strongest compound action potential.

      Hope that helps!

  4. JRT May 11, 2011 at 9:20 am #

    Thank you so much for this video. I FINALLY understand the definition! I hope I’ll be able to explain it back on the test.

    • Lrsamuel May 11, 2011 at 9:29 am #

      You are very much welcome. Glad you understand it now. You should be fine for the test :)

  5. MsNany17 October 24, 2011 at 5:30 pm #

    u made me understand it very well
    keep going l

  6. bcassie3 October 25, 2011 at 2:21 pm #

    I’m still confused on the action potential source. The membrane potential creates a local graded potential in a cell and when excitable cells recieve a stimulus they create an electrical action potential that travels from the stoma to the axon to the synapse?? Is this correct?

  7. mjcari1001 October 25, 2011 at 7:26 pm #

    you are adorable! thank you !!

  8. unfeignedfaith October 31, 2011 at 3:37 am #

    @InteractiveBiology Awesome! Love gospel music!!! FRIEND OF GOD! ;D

  9. ultrapsyk0 November 3, 2011 at 11:55 am #

    great job man!

  10. raysrbeast08 November 5, 2011 at 6:49 pm #

    Plain as the light of day. A huge thank you from the center of my heart.

  11. Anna32071 November 6, 2011 at 8:52 pm #

    dude.. you are awesome….simple simple ….easy.
    I’m not a doctor or a nurse and i am not gonna be.(unfortunately or …!).
    but i had to take an anatomy class …and it is killing meeee…BUT YOU MAKE MY LIFE SO EASYYYYYYYYYYYYYYY.
    best of luck to you :x

  12. InteractiveBiology November 7, 2011 at 6:02 am #

    @ultrapsyk0 Thank you! Glad to know you liked our Biology site. Do stay tuned for more.

    • Char February 2, 2012 at 1:51 am #

      You can always tell an expert! Thanks for contirubitng.

      • Leslie Samuel February 2, 2012 at 2:59 pm #

        Why thank you Char. I wouldn’t consider myself an expert, but I sure do enjoy learning ;)

  13. InteractiveBiology November 7, 2011 at 6:03 am #

    @raysrbeast08 Our pleasure. We will provide you with more Biology videos, so do stay tuned!

  14. InteractiveBiology November 7, 2011 at 6:06 am #

    @Anna32071 LOL! We’re glad to know that we have made things easier and simpler for you. Stay tuned, because there will be more Biology videos coming :)

  15. InteractiveBiology November 7, 2011 at 6:09 am #

    @mjcari1001 You’re welcome! Stay tuned because we have more Biology videos coming :)

  16. chrissline77 November 18, 2011 at 7:03 pm #

    Action potentials are unidirectional, all or none waves of depolarization

  17. chikifree November 22, 2011 at 10:17 pm #

    you should be my teacher.

  18. InteractiveBiology November 23, 2011 at 8:53 am #

    @chikifree Thank you :)

  19. ojay12341234 November 26, 2011 at 3:34 pm #

    hey you did a great job. listen i don’t speak english very well but i have a question and i hope it will make sense
    when sodium ions go inside the cell and potassium.. does it happen through the sodium potassium pumb????
    i hope you answer

  20. ojay12341234 November 26, 2011 at 3:35 pm #

    hey you did a great job. listen i don’t speak english very well but i have a question and i hope it will make sense
    when sodium ions go inside the cell and potassium ions go outside.. does it happen through the sodium potassium pump????
    i hope you answer

  21. InteractiveBiology November 27, 2011 at 10:06 pm #

    @ojay12341234 Thank you! Unfortunately, Leslie no longer have the time to go through all of the overwhelming emails he has been receiving. He’s busy with the site working on more Biology videos. So, please stay tuned!

  22. anfro18 December 6, 2011 at 6:55 pm #

    @ojay12341234 I hope you ended up getting the information, but its quite a bit more difficult than just the sodium potassium pump. there are specific pumps that open during an action potential called “ligand gated channels”, “voltage gated channels” “mechanical gated channels and leaky channels. I’d advise looking into the ligand gated and voltage gated as they are the most important.. Feel free to message me if you want more information.

  23. bdemare00 December 7, 2011 at 12:01 am #

    damn nigga thx , ill never be racist anymore !

  24. kvmackay1321 December 7, 2011 at 2:09 am #

    Seriously, you are great. You make it so clear! Textbook is ridiculous, wish I thought to look concepts on youtube early, but made it in just before my final! Thanks!

  25. InteractiveBiology December 8, 2011 at 9:36 am #

    @kvmackay1321 Well, good luck with your exams. We hope you’ll ace it with Leslie’s help :) Have fun learning!

  26. Whocares05050 December 10, 2011 at 7:16 pm #

    Good videos but please get to the point faster. thanks.

  27. InteractiveBiology December 11, 2011 at 1:17 am #

    @Whocares05050 Thank you! And, thank you for your suggestion. That will help us make our videos even better. Please stay tuned, we have more Biology videos coming very soon!

  28. themidnightdaylight December 14, 2011 at 11:12 pm #

    So that what what an iPhone is! lol just kidding :P good video :)

  29. InteractiveBiology December 15, 2011 at 1:17 pm #

    LOL!

  30. Vijay Singh Kunwar December 18, 2011 at 9:59 am #

    man you are super-duper cool teacher, that is what we all students need!!
    and your videos are really helping me a lot!! thanks a lot!

  31. punkvijay224 December 18, 2011 at 9:59 am #

    man you are super-duper cool teacher, that is what we all students need!! and your videos are really helping me a lot!!

    thanks a lot!

  32. InteractiveBiology December 18, 2011 at 5:33 pm #

    @punkvijay224 Thank you :) Glad to know the videos are helping. Please stay
    tuned for more Biology videos to be uploaded to the site. have fun!

  33. InteractiveBiology December 18, 2011 at 5:33 pm #

    @punkvijay224 Thank you :) Glad to know the videos are helping. Please stay tuned for more Biology videos to be uploaded to the site. have fun!

  34. paradigmentropy January 1, 2012 at 3:06 pm #

    Thanks a ton for the video! Can I make one minor suggestion? For future videos, can you find a way to upload it with stereo audio? I only hear it in my left headphone (which is a bit of a distraction… but its a very minor inconvenience, still a great video).

  35. MrBumpie January 12, 2012 at 8:58 am #

    thank you so much! I’m an old dude 50+ yrs. I wish I would have had someone like you for a teacher years ago. maybe I did but just didn’t pay attention….haha. keep up the Great work.

  36. justinkendle January 18, 2012 at 1:35 am #

    Good job

  37. ojay12341234 January 22, 2012 at 5:36 pm #

    @anfro18 Thank you, sir.

  38. ojay12341234 January 22, 2012 at 5:36 pm #

    Thank you, sir.

  39. fhealer1 January 24, 2012 at 4:49 pm #

    What a great video! I was confused about Action Potential on my lecture
    yesterday, I came to you tube for quick look and I found you. It was so
    clear, well presented and well described. I am gone go home now with smile
    knowing what Action Potential is after spending time by studying in
    library. Please keep it up ,to help student like me. God Bless you, u make
    my life a bit easier! thank you :) oh! I also like your smile.

  40. fhealer1 January 24, 2012 at 4:49 pm #

    What a great video! I was confused about Action Potential on my lecture yesterday, I came to you tube for quick look and I found you.
    It was so clear, well presented and well described. I am gone go home now with smile knowing what Action Potential is after spending time by studying in library. Please keep it up ,to help student like me. God Bless you, u make my life a bit easier! thank you :) oh! I also like your smile.

  41. KOKUSTTP January 30, 2012 at 6:46 pm #

    Leslie, thankyou so much for explaining biology so simply and easy to understand – your visuals and easy going manner make me feel less pressure about learning this stuff! Wish you the best!!

  42. Lynn1Fargo January 31, 2012 at 2:20 pm #

    Ive just get my Human physiological proceses egzam results.
    There was a question about rest state of a neuron.
    What movment occurs during the rest state?
    What movments of Na and/or K.
    Ive marked that there is no movemnet at all. But the teacher said iam wrong. Could you please explain me this plzzzzzzzzzzz

  43. yehudithlee February 4, 2012 at 4:52 pm #

    You are AWESOME! I finally get what an action potential is–I will be watching the rest of your videos. Thanks again–may God bless you abundantly for taking the time to do this!

  44. redon781 February 5, 2012 at 2:14 pm #

    amazing amazing amazing! Thank you for these videos.

  45. tinajanami February 5, 2012 at 8:42 pm #

    for some strange reason i dont know what an ipod is LOL

  46. aaahhhkkk2010 February 6, 2012 at 4:15 pm #

    @Lynn1Fargo Hey I can answer :D, there is a K movement only because K ion channels are the only channels that remain opened during resting potential… so any change in the resting potential will depend directly on K..

  47. aaahhhkkk2010 February 6, 2012 at 4:15 pm #

    Hey I can answer :D, there is a K movement only because K ion channels are the only channels that remain opened during resting potential… so any change in the resting potential will depend directly on K..

  48. LucidDreamz February 7, 2012 at 4:21 pm #

    No offense but that was a over simplification of this concept. You said nothing about what drives an action potent and it’s functioning. How are you going to explain AP without even mentioning Na+/K+, voltage-gated channels, electrical excitability, etc.

  49. Caribbeanpearl09 February 8, 2012 at 10:06 pm #

    @aaahhhkkk2010 Is that how it is propagated down an axon??

  50. Caribbeanpearl09 February 8, 2012 at 10:06 pm #

    Is that how it is propagated down an axon??

  51. Caribbeanpearl09 February 8, 2012 at 10:06 pm #

    Is that how it is propagated down an axon??

  52. Caribbeanpearl09 February 8, 2012 at 10:10 pm #

    so action potential is propagated down an axon by stimulation from one action potential to the next????????

  53. aaahhhkkk2010 February 9, 2012 at 1:23 pm #

    @Caribbeanpearl09 No you know that the Na channels are stimulated by the voltage changes..The depolarization state will cause a difference in voltage, this will stimulate any nearby Na channels to open…K channels are slower than Na ones in closing, Na channels on the first end of Action pot. will wait for K channels to be closed, Na chan. won’t open even if there was a stimulus as long as K chan. are opened…This will cause the movement of Action pot. in one direction in the axon..

  54. aaahhhkkk2010 February 9, 2012 at 1:23 pm #

    No you know that the Na channels are stimulated by the voltage changes..The depolarization state will cause a difference in voltage, this will stimulate any nearby Na channels to open…K channels are slower than Na ones in closing, Na channels on the first end of Action pot. will wait for K channels to be closed, Na chan. won’t open even if there was a stimulus as long as K chan. are opened…This will cause the movement of Action pot. in one direction in the axon..

  55. aaahhhkkk2010 February 9, 2012 at 1:30 pm #

    @Caribbeanpearl09 simpler, at the first end of action potential Na channels have been opened once earlier…It won’t be opened again until the K channels closed…at the second end Na channels haven’t been opened earlier, think of them as virgins, so any change in voltage will open them, then Na chan. will be closed in the new area of the axon, K will open, Na will wait for them to close in order to be able to open again, virgins of the newer area will open…and so on and so on…

  56. aaahhhkkk2010 February 9, 2012 at 1:30 pm #

    simpler, at the first end of action potential Na channels have been opened once earlier…It won’t be opened again until the K channels closed…at the second end Na channels haven’t been opened earlier, think of them as virgins, so any change in voltage will open them, then Na chan. will be closed in the new area of the axon, K will open, Na will wait for them to close in order to be able to open again, virgins of the newer area will open…and so on and so on…

  57. ahmad21352 February 12, 2012 at 8:49 am #

    what is resting potential?

  58. taramcgara1 February 16, 2012 at 7:54 pm #

    Awesome! I am a TA for a College Anatomy course and I refer students to your videos for clarification and review.

  59. taramcgara1 February 16, 2012 at 7:54 pm #

    Awesome! I am a TA for a College Anatomy course and I refer students to your videos for clarification and review.

  60. sushanta313 February 21, 2012 at 3:07 am #

    Can You do a video on how the electrical impulse traveled through out the axons and what causes them to move?

  61. ImTheSaxMan February 27, 2012 at 10:49 am #

    Wayne brady? is that you? just kidding

  62. OhDearShiz March 10, 2012 at 10:08 pm #

    your teeth.. wow white.

  63. pspdslite5991 March 15, 2012 at 5:18 am #

    great vid, thanks man

  64. JDB091 March 15, 2012 at 2:16 pm #

    Hi! We use your episodes in our cardiology class in Belgium! They are really helpfull, although in the beginning we thought our teacher was a bit lazy.. ;-)
    Greetings!

  65. afiste March 19, 2012 at 6:23 pm #

    Thank you so much for posting all this videos. God Richly Bless You!!!!!

  66. ca8620 March 20, 2012 at 9:48 am #

    i don’t think, that black ppl should think about things like that… come on… seriously… u should sell drugs or shit like that dog!

  67. Anthony Owusu March 23, 2012 at 1:43 pm #

    if you have a problem with black people, then hop off the vid. ignorant
    people like you NEED to DIE!

  68. ummmanthony March 23, 2012 at 1:43 pm #

    if you have a problem with black people, then hop off the vid.
    ignorant people like you NEED to DIE!

  69. SafinaShah March 27, 2012 at 1:01 pm #

    Thank you so much. you really make biology fun.

  70. ca8620 March 30, 2012 at 9:58 am #

    such kidding dog

  71. ca8620 March 30, 2012 at 9:58 am #

    such kidding dog

  72. ca8620 March 30, 2012 at 9:59 am #

    i’m even black

  73. ca8620 March 30, 2012 at 9:59 am #

    i’m even black

  74. ca8620 March 30, 2012 at 9:59 am #

    in mind

  75. ca8620 March 30, 2012 at 9:59 am #

    and white on skin

  76. ca8620 March 30, 2012 at 9:59 am #

    and white on skin

  77. AReeves78 April 1, 2012 at 5:26 pm #

    This is too simplistic even for teenagers. Who is your target audience?

  78. AReeves78 April 1, 2012 at 9:26 pm #

    This is too simplistic even for teenagers. Who is your target audience?

  79. andydude91 April 3, 2012 at 11:30 pm #

    Please tell me apple are paying you for this! :P
    Anyways, awesome vid, keep it up.

  80. andydude91 April 3, 2012 at 11:30 pm #

    Please tell me apple are paying you for this! :P
    Anyways, awesome vid, keep it up.

  81. andydude91 April 4, 2012 at 3:30 am #

    Please tell me apple are paying you for this! :P
    Anyways, awesome vid, keep it up.

  82. mandyken19 April 4, 2012 at 4:56 am #

    our teacher use this video’s for the lesson’s in the university. it makes the lesson’s more amusing :) and it makes studying a little bit easier :)

  83. mandyken19 April 4, 2012 at 8:56 am #

    our teacher use this video’s for the lesson’s in the university. it makes the lesson’s more amusing :) and it makes studying a little bit easier :)

  84. o7980 April 5, 2012 at 12:26 pm #

    Tanx for this wondeful add…pls i would some lectures on G proteins

  85. o7980 April 5, 2012 at 4:26 pm #

    Tanx for this wondeful add…pls i would some lectures on G proteins

  86. torktt April 8, 2012 at 9:34 pm #

    merci mile fois de vos amis de Canada!

  87. torktt April 9, 2012 at 1:34 am #

    merci mile fois de vos amis de Canada!

  88. BeckyOC861 April 14, 2012 at 2:56 am #

    SO GOOD! I’ve found a video that makes learning this stuff easier. Thank you :) Top shelf!

  89. BeckyOC861 April 14, 2012 at 6:56 am #

    SO GOOD! I’ve found a video that makes learning this stuff easier. Thank you :) Top shelf!

  90. josie April 14, 2012 at 2:42 pm #

    Hey,
    Awesome videos can you please do one on blood,red and white cells and plateletes

  91. danchisholm1 April 15, 2012 at 4:45 am #

    You rock, Leslie. Keep helping make our world smarter.

  92. Daniel Chisholm April 15, 2012 at 8:45 am #

    You rock, Leslie. Keep helping make our world smarter.

  93. Daniel Chisholm April 15, 2012 at 8:45 am #

    You rock, Leslie. Keep helping make our world smarter.

  94. theadnanism April 18, 2012 at 6:37 pm #

    thanks for video but the explaination of action potential is more than what he said.

  95. theadnanism April 18, 2012 at 6:37 pm #

    thanks for video but the explaination of action potential is more than what he said.

  96. theadnanism April 18, 2012 at 10:37 pm #

    thanks for video but the explaination of action potential is more than what he said.

  97. mrsjdunigan1 April 26, 2012 at 4:08 am #

    Glad I found your video because I couldn’t grasp the reading material and when I saw your video I then felt kind of like wow I can understand that LOL..anyways I look forward getting educated by your videos. :-) God Bless

  98. mrsjdunigan1 April 26, 2012 at 8:08 am #

    Glad I found your video because I couldn’t grasp the reading material and when I saw your video I then felt kind of like wow I can understand that LOL..anyways I look forward getting educated by your videos. :-) God Bless

  99. lehnabanana May 1, 2012 at 6:19 pm #

    Dude, this is so great! Thanks a lot for putting so much time into all this. It’s so helpful!

  100. lehnabanana May 1, 2012 at 6:19 pm #

    Dude, this is so great! Thanks a lot for putting so much time into all this. It’s so helpful!

  101. lehnabanana May 1, 2012 at 6:19 pm #

    Dude, this is so great! Thanks a lot for putting so much time into all this. It’s so helpful!

  102. nuraj niroshana May 2, 2012 at 9:10 pm #

    awsome put siri to ur iphone 4!!!!!!

  103. nuraj niroshana May 2, 2012 at 9:10 pm #

    awsome put siri to ur iphone 4!!!!!!

  104. Anonymous May 2, 2012 at 9:10 pm #

    awsome put siri to ur iphone 4!!!!!!

  105. SuperCrazyIdiot May 5, 2012 at 2:43 pm #

    you forgot the actual action potential with a sodium potassium pump

  106. SuperCrazyIdiot May 5, 2012 at 2:43 pm #

    you forgot the actual action potential with a sodium potassium pump

  107. oOozmyoOo May 6, 2012 at 9:50 am #

    i feel like im getting one on one tutoring! you are amazing!!

  108. oOozmyoOo May 6, 2012 at 9:50 am #

    i feel like im getting one on one tutoring! you are amazing!!

  109. oOozmyoOo May 6, 2012 at 9:50 am #

    i feel like im getting one on one tutoring! you are amazing!!

  110. lucylucylol May 6, 2012 at 8:06 pm #

    You are an amazing teacher :)

  111. lucylucylol May 6, 2012 at 8:06 pm #

    You are an amazing teacher :)

  112. lucylucylol May 6, 2012 at 8:06 pm #

    You are an amazing teacher :)

  113. temporaryguy May 7, 2012 at 1:34 am #

    This guy is cool. Is it racist that I always think black people are cool?

  114. temporaryguy May 7, 2012 at 1:34 am #

    This guy is cool. Is it racist that I always think black people are cool?

  115. abdul samad May 9, 2012 at 9:38 am #

    sir is mutation beneficial?

  116. abdul samad May 9, 2012 at 9:39 am #

    is mutation beneficial?

  117. EjPwned May 10, 2012 at 6:45 pm #

    1:28 to start.

  118. EjPwned May 10, 2012 at 6:45 pm #

    1:28 to start.

  119. marxandmarzipan May 12, 2012 at 4:31 pm #

    i think i love you x

  120. marxandmarzipan May 12, 2012 at 4:31 pm #

    i think i love you x

  121. cyttv888 May 12, 2012 at 10:59 pm #

    studying for the AP bio exam and this is really helping me clarify a lot of stuff that weren’t as clear as before! thanks for these videos!

  122. cyttv888 May 12, 2012 at 10:59 pm #

    studying for the AP bio exam and this is really helping me clarify a lot of stuff that weren’t as clear as before! thanks for these videos!

  123. Narjes May 20, 2012 at 9:57 pm #

    Hi
    I really like your explanation in your videos you made everything complicated much easier for me. Please if you can talk about the cable theory of the neuron and the spatial constant and time constant and how the neuron works as a capacitor and resistor that would be of great help. I will take my PhD first level exam soon and I have some problems in understanding the cable theory of the neuron.
    Thank you so much

  124. pixiesashes May 31, 2012 at 6:36 pm #

    you are the best!!

  125. pixiesashes May 31, 2012 at 6:36 pm #

    you are the best!!

  126. Muneeb Ishtiaque June 4, 2012 at 7:35 am #

    Wow, this is a really helpful video. I am in year 9, and I love science and want to go into the neuroscience side. You have helped me so much, and i appreciate it.

    Thank you!!

  127. Muneeb Ishtiaque June 4, 2012 at 7:35 am #

    Wow, this is a really helpful video. I am in year 9, and I love science and want to go into the neuroscience side. You have helped me so much, and i appreciate it.

    Thank you!!

  128. spriteme19 June 5, 2012 at 4:19 pm #

    Thank you so much for uploading this! I have my end of semester exam on Tuesday next week and action potentials are something that have also proven to be a pain to try remembering but you have given me an easier way to remember!

  129. spriteme19 June 5, 2012 at 4:19 pm #

    Thank you so much for uploading this! I have my end of semester exam on Tuesday next week and action potentials are something that have also proven to be a pain to try remembering but you have given me an easier way to remember!

  130. louise geraghty June 8, 2012 at 3:25 am #

    I think you’re brilliant. Thank you so much for giving this to the world.

  131. BeckyOC861 June 11, 2012 at 8:13 am #

    Agreed. Uni lectures could learn alot from his approach. Legend.

  132. BeckyOC861 June 11, 2012 at 8:13 am #

    Agreed. Uni lectures could learn alot from his approach. Legend.

  133. BeckyOC861 June 11, 2012 at 8:13 am #

    Agreed. Uni lectures could learn alot from his approach. Legend.

  134. reality237 July 7, 2012 at 12:07 am #

    Handy Dandy…….Iphone! (blues clues) lol ur so kool… ur vids make me excited about learning and are really helping alot my lecture professor seems more confused than me sometimes lol

  135. reality237 July 7, 2012 at 12:07 am #

    Handy Dandy…….Iphone! (blues clues) lol ur so kool… ur vids make me excited about learning and are really helping alot my lecture professor seems more confused than me sometimes lol

  136. muummy22 July 29, 2012 at 3:06 am #

    simple, short, and using props, pictures, ect…. you did a great job and you made it seem fun not boring. it take 7 times to remember something so being easy to understand and fun helps

  137. veer July 31, 2012 at 8:33 am #

    ur so amazing teacher

  138. veer July 31, 2012 at 8:35 am #

    i want to now about pharmacology of nervous system sir

  139. tali2182 August 14, 2012 at 2:17 am #

    love your vids you are awesome!

  140. aisha7396 August 28, 2012 at 8:01 am #

    Really gud!!

  141. Lucy Lopez September 7, 2012 at 6:15 pm #

    You are truly great! Thank you for doing this videos!

  142. sunset721 September 17, 2012 at 2:03 am #

    Your videos are very helpful. Just wondering why you don’t have a video for graded potentials or the differences between the two (action and graded potentials). Keep up the great work!

  143. LadiiGreen88 September 18, 2012 at 5:53 pm #

    Thank you so much!! Your video really helped!

  144. PandTfilms59 September 23, 2012 at 7:58 pm #

    Get to the point! Too much dialogue explaining what you will talk about…it takes you almost 3 minutes into the video to answer the question.

  145. d12str September 23, 2012 at 7:58 pm #

    guy in the video is cutteeee ;)

  146. Gatikabela September 24, 2012 at 4:55 pm #

    The audio on this video is not working on my end. I do not know if I am the only one with this problem. Can you check to see what seems to be causing no sound on my end. Thank you.

  147. InteractiveBiology September 25, 2012 at 12:55 am #

    It’s perfectly working on our end. You might want to check your settings and try it again.

  148. Rob Bland September 25, 2012 at 8:11 am #

    Audio only working in mono

  149. SGVliverSHOT626 September 29, 2012 at 2:19 am #

    ya im only hearing it on one side

  150. ItsMeTasneem September 30, 2012 at 2:59 am #

    just started physio and your videos are very helpful and you make concepts easier to understand (compared to my professor just reading off powerpoint slides)! Thank you!

  151. lauratew October 5, 2012 at 10:30 am #

    My class are gonna love you!

  152. MIKON2014 October 5, 2012 at 11:16 am #

    Hi, just want to say I was really impressed by your presentation, I suggest you send some of your videos to TV broadcasters, I think you would be a really refreshing and inspirational TV Science presenter to lots of young people! Good luck and success with whatever you do…

  153. SaddieMusic October 5, 2012 at 11:38 am #

    1:30 … you’re welcome!

  154. AmorVincitOmniaxX1 October 7, 2012 at 9:19 am #

    YOU’RE AMAZING! Thank you for doing this :-)

  155. felicita843 October 7, 2012 at 8:52 pm #

    please explain the after potential

  156. felicita843 October 7, 2012 at 8:53 pm #

    your videos are nice

  157. Dan Brobst October 11, 2012 at 3:43 pm #

    that was a long video to answer one question :) just saying

  158. sent18inel October 13, 2012 at 9:32 pm #

    I think it’s mono and not stereo. I’m only getting audio out of my left speaker.

  159. Lee Vui October 14, 2012 at 11:09 pm #

    iPhone 4….

  160. crazysurfergirl October 21, 2012 at 11:21 am #

    omg u explain sooo well ! totally understood. i was having some trouble with the action potential !!!

  161. tekierobby October 27, 2012 at 7:41 pm #

    So help full…

  162. brian1rr1 October 31, 2012 at 5:36 am #

    Omg who is dentist hes smile it’s perfect

  163. belise dusenge October 31, 2012 at 5:53 pm #

    thanks you are the best def helped me

  164. LivingOracles November 1, 2012 at 11:23 pm #

    wow your lessons are so easy to understand thanks

  165. Alia Diana November 4, 2012 at 10:05 pm #

    thanks professor samuel. you are genius! i hope you can make a video about clinical and ontogenetical division of encephalon. thanks :)

  166. VictoriaSobocki November 12, 2012 at 9:06 pm #

    nice way of explaining :)

  167. Shannon November 16, 2012 at 1:49 pm #

    i like your videos… they’re simple and straight forward. Thank you

  168. lordthorpez November 17, 2012 at 8:01 pm #

    aweful

  169. dafunk666 November 18, 2012 at 10:53 am #

    Omg his dancing made me laugh <3

  170. mynameislin November 20, 2012 at 2:21 am #

    i wish you were my professor

  171. Sarpomaa Priscilla November 24, 2012 at 4:21 am #

    You teach soo well you need to be in the neouroscience field…..good job :-)

  172. lorecrazy1 November 25, 2012 at 2:33 pm #

    how do I find the rest of his videos about ion channels and how they work?

  173. criminalwins December 5, 2012 at 6:53 pm #

    can’t you put the sound on both speakers in sony vegas or something? it’s so annoying as I’m wearing headphones.

  174. Alexandra Pope December 13, 2012 at 8:21 pm #

    Too long before getting into what the video is supposed to be about. Halfway in I still didn’t under what an action potential is.

  175. Soccer Guru December 17, 2012 at 10:14 pm #

    I had a Bio final tomorrow, and I was super stressed out because I didn’t know this, but thank you! You helped me a lot! Can you explain to me what sodium pumps are, and what role they play in this process?

  176. Soccer Guru December 17, 2012 at 10:15 pm #

    I had a Bio final tomorrow, and I was super stressed out because I didn’t know this, but thank you! You helped me a lot! Can you explain to me what sodium pumps are, and what role they play in this process?

  177. nesalasica December 28, 2012 at 11:13 pm #

    You didnt explain what are the sodium pumps and how does action potential work…

  178. anru2006 December 31, 2012 at 4:45 pm #

    I think Apple sponsored this video..

  179. dalodalo90 January 5, 2013 at 5:53 pm #

    man u r the best!

  180. Henry Chen January 8, 2013 at 3:19 am #

    the question in this vid was just what an action potential is not how it works lol

  181. 7StepzUnderTheSun January 11, 2013 at 5:42 am #

    Thank you :)

  182. Nebojsa Lasica January 11, 2013 at 11:45 am #

    dont play smart ass on me

  183. RUTHYABU February 2, 2013 at 12:24 pm #

    amazing! thank you !

  184. Kusiima Jimmy February 11, 2013 at 8:28 pm #

    An action potential is generated by a sudden momentary increase in the permeability of the axon membrane to Na+ ions which enter the axon.

  185. jankyjay253 February 26, 2013 at 4:34 am #

    Sounds work for me. Sounds like it’s only coming out of the left speaker, though.

  186. jhercules26 March 2, 2013 at 3:02 pm #

    I would never in my life subscribe to a biology channel until I found you. Your methods or describing information is so entertaining to the point where I understood it! Thank you so much.

  187. unitelanka March 6, 2013 at 10:03 pm #

    audio is working but it’s in mono, just in my left speaker.

  188. Tahucha Jean March 9, 2013 at 1:01 am #

    You…just made me understand a 90 minute class lecture…in 5 and a half minutes. O…M…G. My mind is blown.

  189. jerieshaw March 13, 2013 at 11:55 am #

    iPhone 4 ad?

  190. Mamta Simon March 15, 2013 at 4:36 am #

    wow ..so intrestin nd easy way to understnd action potential……or…music potential

  191. Kim Ly March 17, 2013 at 5:16 pm #

    I love you, you are the best. All your lectures are very clear to me :) You have a way to make your lectures very easy to understand. Thank you

  192. mydee12 March 23, 2013 at 2:21 am #

    Does thought create an action potential?

  193. bellabella bella April 6, 2013 at 5:46 pm #

    Thank you very much

  194. I Em Pac April 18, 2013 at 8:49 pm #

    why cant you just shut the fuck up bro and start talking, gosh… what is action potential

  195. nieves carter April 19, 2013 at 10:59 pm #

    How rude of you! You should be ashamed of yourself :( If you don’t like it… move on!

  196. Lora G April 22, 2013 at 4:10 pm #

    Oh my gosh, I seriously want to take you home in my pocket! My husband might not mind!

  197. acash93 April 24, 2013 at 3:26 am #

    Youtube should make a university using your videos. They explain way better than my lecturer and in less time as well! Thank you very much.

  198. Lazoo23 April 24, 2013 at 10:28 am #

    My lecturer’s notes and explanations are a mess, missing basic information and the notes not even referring to the meanings of some acronyms she uses. With my exam around the corner and none of what my lecturer says making sense i’m in a lot of trouble. Fortunately a friend pointed me to your videos which is really helping me out a lot and I could definitely use any help I can get.

    I really appreciate these videos as they’re of tremendous help. Thanks a lot!

  199. Kym Adair April 27, 2013 at 7:34 pm #

    So much easyer to understand ty!!!!!!!!

  200. Sarita Chauhan May 3, 2013 at 3:59 am #

    nice lecture sir

  201. Vanessa de Carvalho Oliveira May 5, 2013 at 4:06 pm #

    007 license to kill

  202. Shaghayegh Khatabi May 7, 2013 at 2:17 pm #

    Awesome job, all of your videos are really helpful, thanks

  203. TTerminatorr May 9, 2013 at 5:35 am #

    Great videos, love how your aim is purely to teach instead of adding to much unnecessary information. I’m subscribed well done. And Thank you.

  204. jgdjshfshdhfsdhfs May 21, 2013 at 12:37 pm #

    I’m going ti stimulate this iphone…;)

  205. charles jimingo May 24, 2013 at 8:15 am #

    what will happen if the message does’nt sent to the
    brain

  206. Nikki Jackson May 24, 2013 at 8:22 am #

    Thank you so much! Need more teachers like you. Love the easy to understand example.

  207. carlondutyrock May 28, 2013 at 8:32 pm #

    who are the 46 dumb idiots who would dislike this video!

  208. carlondutyrock May 28, 2013 at 8:32 pm #

    who are the 46 dumb idiots who would dislike this video!

  209. vladbio June 7, 2013 at 3:22 pm #

    Great channel. Great videos.
    I waswondering if this is the place to ask about LTP, NT, and in general some issues in neurophysiology.

  210. thewakeboarder June 12, 2013 at 6:04 pm #

    Its just mono on my headphones… only the left ear works. Kind of Annoying, fix if if you can. but otherwise still awesome videos.

  211. Tipsjebris June 16, 2013 at 10:15 am #

    I love your videos. Thank you so much, you totally helped me through my veterinary medicine examns.

  212. teenagemania June 29, 2013 at 7:16 am #

    Its nt working here too… all the other youtube sound are working… only ur vid

  213. Mexuverse San June 29, 2013 at 6:50 pm #

    I have sound on this video but it’s blurred, like only the bass is on…
    I’m watching a video under water, awesome!

  214. Thomas Cho July 17, 2013 at 4:43 am #

    the sound comes out only on the left side of my earphone

  215. David Porter July 21, 2013 at 11:22 am #

    Also, mine. It is only coming through on one channel. So if you have head phones or stereo speakers it should come through on one channel.

  216. sreenath851 July 27, 2013 at 2:51 am #

    all videos have been very interesting……..keep up the good work frnd…cld u send me a video of the receptors of the human body.thank u

  217. Sandile Mntambo July 30, 2013 at 9:42 pm #

    hey bra i jst wanted to thank u for your videos they are really helpful

  218. Chera Gillard September 11, 2013 at 7:39 pm #

    Thank you so much for making these videos, they are so helpful! Wish you were my real bio teacher :)

  219. Maggie Tsui September 15, 2013 at 10:02 am #

    THANK YOUUU FOR THE VIDEOO OMGGG
    it is so helpful :)
    i always like videos like this ^^
    please keep making more videosss!!!! :D :D :D

  220. rkagrawal75 September 17, 2013 at 10:05 pm #

    How can I find the list or Playlist of related topic video in series so that i can move back and forth

  221. Dang Shu September 21, 2013 at 2:56 am #

    This is a really simple video. You do not go through the sodium/potassium pumps, depolarization, refractory period nor resting state. This are core topics that average biology students would learn so please make videos about these.

  222. itzeelvargaas September 22, 2013 at 9:57 pm #

    audio isnt working

  223. littleismail October 13, 2013 at 1:24 pm #

    . I have to train my mind to determine how I will interpret the signals I am receiving.

  224. RICHARD SANKAR October 18, 2013 at 12:49 pm #

    audio only working in one ear bud = action potential only travels through one of the axon terminals xD

  225. Charles Henry October 21, 2013 at 9:05 pm #

    no audio

  226. HaakonCBG October 22, 2013 at 7:44 am #

    Lets cut to the case: 1:25

  227. Katie Bowman October 24, 2013 at 8:31 pm #

    Video was helpful for me. Explained things clearly. Thank You

  228. Basma Saady October 26, 2013 at 6:17 pm #

    that was pretty good,,thanks :))

  229. spetruck1 November 12, 2013 at 6:02 pm #

    cut the first 1:28 out.

  230. spetruck1 November 12, 2013 at 6:03 pm #

    horrible. I don’t care what an ipod is.

  231. Mathew Kiio November 19, 2013 at 6:14 am #

    Great Videos..easy to understand..

  232. Mathew Kiio November 19, 2013 at 6:15 am #

    Great Videos

  233. bheemanna March 16, 2014 at 9:49 pm #

    very good explination thank u sir it is most understandable

  234. Mikail Adam May 10, 2014 at 10:47 pm #

    thanks Mr Leslie,you made me understanding physiology easier than before.you’re such a great guy.thanks a lot