Thank you. You just saved me a possible 40 minutes trying to figure out what my textbook is trying to tell me haha, 20 minutes of aimlessly staring into the pages and another 20 trying to read half latin/greek derived words. You display complex effects in simple terms and still manage to include all the crucial information.
@mlalramhluna Thank you. It's what Leslie's main goal is, to be able to share his knowledge to those who need them. Glad that you're finding value in his videos. Stay tuned for more Biology fun!
You save my life. I'm a working child and I end up missing a lot of class so these videos really really help me. Plus, you make things easy to understand and give a reason for everything which in turn makes it super easy to follow.
just want to say thank you for making my life SO much easier 'cause I have an exam thats going to be 18 chapters...I don't know how I will read it all. THANKS a lot :D
This video simplified the SA/VA sequence perfectly! I think I'll stop reading my A & P text book, and instead, watch every video you have created. Thank you for making this process interesting instead of complicated!
I've been watching a few video of yours on the heart and have managed to learn more from you in a few simple minutes than I have all semester. Thank you so much for your hard work and effort it truly shows and I seriously appreciate you and wish you everything good in this world. Thanks to you I'll be able to ace my exam next week. You've literally taught and helped out so many future students, nurses and doctors!
I just love how this particular person gives free lectures plus all the interactive are very easy for me to understand..keep up the good work leslie! You're making everyone's life easier :)
i got 87.5 on my first lecture exam , i used your information and i guess it works out really well.... you don't need be a rocket scientist to understand this.:)
@greenranger8100 You are VERY much welcome. Glad to know it's helping. All the best, and stay tuned for many more in the future. Make sure to subscribe!
Please continue doing what you do! I love your videos and they are soon HELPFUL!!!! Thank you for helping me understand human physiology, the videos help me pass the class.
This all is actually not quite true. Ca2+ channels are slow channels, so the action potential gets a round figure instead of the sharp, fast figure you illustrated. (The sharp fast figure is when de the fast Na+ channels lead the action potential, like in normal muscle cells) Also, when the threshold is passed, the Na+ channels close, so during a action potential there is no Na+ influx.
i think it is exactly like this that the calcium goes fastly inside uring the SA node action potential.But when it comes to the general AP in cardiac muscle cells the Na/ca channels are slow and thats why there is created an plateau!
During funny current that is when the membrane potential rises from -60 to -40 mv,then with the funny channels ther is opening of transient type of ca channels which helps to achieve the firing potential and after that slow L type ca channels open and depolarise the cell upto the pick point slowly,and it takes 100 m.secs. so we get a flattend pick in the ap graph
@zackboomer Unfortunately, Leslie is busy at the moment with more work to do for the site. He is unable to answer any questions. But, do stay tuned because more biology videos are coming very soon!
@zamirahbasher All questions are answered in the Interactive Biology community forums from now on. Go to the website in the description and then visit the community. This is to make it as efficient as possible as we have multiple people over there to help answer questions. All the best
There are two types of cardiac muscles: contractile muscle cells and autorhythmic muscle cells. Contractile cells make up 90% of muscle cells in the heart and autorhythmic cells make up 10% in the nodes. Autorhythmic muscle cells start the action potentials from the SA and AV nodes that disseminate into contractile cells causing them to contract. InteractiveBiology described the action potential of autorhythmic cells, you described contractile cells. Hope this helped :P
I really just need to verify/clarify something: The sodium ion continuously pumps into the cell and never has a period that it changes course and gets pumped out by Na/K pumps?? This seems counter-intuitive - sodium can't just enter the cells forever without putting a huge osmotic pressure on the cell and bursting it??? Can it?
@petercourt That's a great question. I'm actually not sure that I know the answer to that one. I tried looking it up, but couldn't find that. My assumption would be that there is a Calcium pump in the membrane that pumps it back out. That would make sense and would cause there to be a driving force for Calcium ions to move back into the cell.
Your movies are great! They are really helpful to me. You explain everything very clear and you summurize everything at the end, which is very nice. I only have one question: what happens to the Calcium ions, which rush into the pacemaker cells?
One listening to this and I understand immediately, after reading 5 times in textbook I still don't know what they are talking about, lol. Thank you, you biology master! I wish you all best
@tiarafazlin17 I LOVE saving lives with Biology :D - Stay tuned for MANY more, and make sure to share the site with EVERYONE you know who might benefit ;)
Leslie? Are you like a biology teacher or something? Maybe you just a nerd. Whatever the case thank you so much sir! I can understand you spoof much more than my cardiac teacher. She might be a super smart retired dr. But, there is something to say a out someone like you that can actually make you understand . I love you voice too. It's soothing and intelligent sounding at the same time.
I like your series of videos but in this case, you really should explain how the Na+/K+ pump works in the pacemaker cell first to set up the potential gradient before the voltage sensitive K+ channels close while the Na+ is still pumped out. At this negative membrane potential, the Na+ starts to flow into the cell against the concentration gradient by diffusion, thus activating the potential of the cell which is the cause leading to -40mV where Ca+2 ions start flooding in.
You are an awesome individual to take the time to put all these videos. And you make it so simple and easy to understand without getting lost. Thanks MUCH!!
Do you have any videos that are more specific with the mentioning of funny channels/T-type channels/L-type channels and when those, specifically, come into the picture, etc?
I thought in phase 0 an HCN or nonselective channel causes a Na influx causing the prepotential .. and because it is nonselective K enters too as it is also positve.. also Ca T type channels contribute to this prepotential pushing it from -50 to -40 then both these channels are inactivated and Ca L type channels are activated causing an influx of Ca and depolarization
great video, possible when the levels of serem in the r. atrium reach a point bridging the av node with the sa node , crossing the terminals with a temporary disconnect or a bigger pathway for current a spark(ark) is generated when on disconnect, possibly a gas is released by the nodes into the upper level of r. atrium when the level of rbc's reaches a high level point creates a bridge between the nodes igniting the gas creating combustion, can you measure concentrations in r. atrium
Thank you very much, Tanishq Patil. I appreciate the compliment. My main goal here is to be helpful. If you haven't already, make sure to subscribe to the channel because I have a lot more content like this coming to help you understand how the human body works.
Can supplementation with Potassium and Magnesium powder up to 4-5000 mg per day be helpful, if diet is only supplying 1000 mg per day, in improving conduction at the S-A node, which has been damaged due to subacute endocarditis, that damaged the node?
Thank you for the video - may I ask. You say Ca2+ flows into the pacemaker cell, but I was curious as to what happens to that calcium, as you didn't say it flows out again, surely it can't keep accumulating in the cell? Thanks again!
since there's a higher concentration of K+ inside the membrane then outside, when K+ channels open, K+ will rush out because ions always move from higher concentrations to lower concentrations. The Na+/K+ pump then uses ATP to pump 2 K+ inside the membrane while pumping 3 Na+ outside so that a high concentration of K+ on the inside, and high concentration of Na+ on the outside will be maintained. This also makes the inside of the membrane negative again and return it to a resting potential.
when potassium leaves a cell not all of it goes. Its only a percentage change that causes the impulse to occur. So during stages in-between stimulation the potassium does move back in and replenish.
THANK YOU :) oh this helps me visually . I could not understand what contraction meant (i speak a different language) but seeing the first part now this really helps more than the text book and the lecture audio from my instructor
+Raven Marshall Or you could say that the depolarisation begins with the opening of the slow voltage-gated Na+ channel till it reaches the threshold where the fast Ca+ channels open and this what drives the depolarisation phase till it reaches its peak!
Thank you for your help. I'm a paramedic student and you broke down the depolarizing-repolarizing ion involvement very well for me to understand (we are currently beginning to analyze ECGs).
Thank you. You just saved me a possible 40 minutes trying to figure out what my textbook is trying to tell me haha, 20 minutes of aimlessly staring into the pages and another 20 trying to read half latin/greek derived words. You display complex effects in simple terms and still manage to include all the crucial information.
Still you should read about it also
@@guytelfer1353it’s been 10 years 😭
Amazing human body.
سبحان الله
@mlalramhluna Thank you. It's what Leslie's main goal is, to be able to share his knowledge to those who need them. Glad that you're finding value in his videos. Stay tuned for more Biology fun!
Couldn't figure the answer to the question Sir...
How do I get to know?
You save my life. I'm a working child and I end up missing a lot of class so these videos really really help me. Plus, you make things easy to understand and give a reason for everything which in turn makes it super easy to follow.
@MissEhouse Thank you! GLad that you seem to be finding value in the videos. Stay TUNED. WE have more Biology videos soon!
two years of med school, and only one video (yours) helped me understand! Thank you so much!
just want to say thank you for making my life SO much easier 'cause I have an exam thats going to be 18 chapters...I don't know how I will read it all. THANKS a lot :D
@kingswood331 Oh yes, definitely! :) We will be uploading more videos soon so, please stay tuned!
সহজ বাংলায় এবং প্রানবন্ত আলোচনার মাধ্যমে এভি AV nodal delay বুঝতে,ক্লিকঃ
ua-cam.com/video/45HDACbAbYA/v-deo.html
This video simplified the SA/VA sequence perfectly! I think I'll stop reading my A & P text book, and instead, watch every video you have created. Thank you for making this process interesting instead of complicated!
I've been watching a few video of yours on the heart and have managed to learn more from you in a few simple minutes than I have all semester. Thank you so much for your hard work and effort it truly shows and I seriously appreciate you and wish you everything good in this world. Thanks to you I'll be able to ace my exam next week. You've literally taught and helped out so many future students, nurses and doctors!
I'm so excited for you. Glad the videos have been helpful. Wishing you all the best on your exam.
@@InteractiveBiology Thank you!!!
You're welcome.
I just love how this particular person gives free lectures plus all the interactive are very easy for me to understand..keep up the good work leslie! You're making everyone's life easier :)
What returns those sodium back out of the cell? They never run out?
i love your videos they are truly helpful and they have made it a lot easier for me to understand your particular topics... more power sir!!!
Glad to hear you are finding value in the videos :)
+Interactive Biology sir is sinoatrial is good to my health??
i got 87.5 on my first lecture exam , i used your information and i guess it works out really well.... you don't need be a rocket scientist to understand this.:)
@greenranger8100 You are VERY much welcome. Glad to know it's helping. All the best, and stay tuned for many more in the future. Make sure to subscribe!
Please continue doing what you do! I love your videos and they are soon HELPFUL!!!!
Thank you for helping me understand human physiology, the videos help me pass the class.
This all is actually not quite true. Ca2+ channels are slow channels, so the action potential gets a round figure instead of the sharp, fast figure you illustrated. (The sharp fast figure is when de the fast Na+ channels lead the action potential, like in normal muscle cells) Also, when the threshold is passed, the Na+ channels close, so during a action potential there is no Na+ influx.
I am not 100% sure, but I think Ca2+ cells are slow in contractile cells, but fast in authorhythmic cells. I could be wrong, though!
i think it is exactly like this that the calcium goes fastly inside uring the SA node action potential.But when it comes to the general AP in cardiac muscle cells the Na/ca channels are slow and thats why there is created an plateau!
During funny current that is when the membrane potential rises from -60 to -40 mv,then with the funny channels ther is opening of transient type of ca channels which helps to achieve the firing potential and after that slow L type ca channels open and depolarise the cell upto the pick point slowly,and it takes 100 m.secs. so we get a flattend pick in the ap graph
@zackboomer Unfortunately, Leslie is busy at the moment with more work to do for the site. He is unable to answer any questions. But, do stay tuned because more biology videos are coming very soon!
@zamirahbasher All questions are answered in the Interactive Biology community forums from now on. Go to the website in the description and then visit the community. This is to make it as efficient as possible as we have multiple people over there to help answer questions.
All the best
There are two types of cardiac muscles: contractile muscle cells and autorhythmic muscle cells. Contractile cells make up 90% of muscle cells in the heart and autorhythmic cells make up 10% in the nodes. Autorhythmic muscle cells start the action potentials from the SA and AV nodes that disseminate into contractile cells causing them to contract. InteractiveBiology described the action potential of autorhythmic cells, you described contractile cells. Hope this helped :P
@madej1858 WOOHOOOOO, Congrats on your success. Nope, rocket scientist is unnecessary :)
I really just need to verify/clarify something: The sodium ion continuously pumps into the cell and never has a period that it changes course and gets pumped out by Na/K pumps??
This seems counter-intuitive - sodium can't just enter the cells forever without putting a huge osmotic pressure on the cell and bursting it??? Can it?
Amazingly helpful vdos
@petercourt That's a great question. I'm actually not sure that I know the answer to that one. I tried looking it up, but couldn't find that. My assumption would be that there is a Calcium pump in the membrane that pumps it back out. That would make sense and would cause there to be a driving force for Calcium ions to move back into the cell.
you just explained that sodium continuously moves into the cell....at what point do they leave
@aikatirah Thank you! Please stay tuned. There will be more Biology videos coming very soon!
@slLLyhumans Thank's for your feedback. You are very much welcome!
That is so helpful! now I finally understood how that system works! Thank you!!:)
@gullwings18 Thank you! Stay tuned for more Biology videos coming very soon!
Your movies are great! They are really helpful to me. You explain everything very clear and you summurize everything at the end, which is very nice. I only have one question: what happens to the Calcium ions, which rush into the pacemaker cells?
One listening to this and I understand immediately, after reading 5 times in textbook I still don't know what they are talking about, lol. Thank you, you biology master! I wish you all best
@tiarafazlin17 I LOVE saving lives with Biology :D - Stay tuned for MANY more, and make sure to share the site with EVERYONE you know who might benefit ;)
brilliant. thank you!
Super easy to follow! I'm hoping your videos help me for my A&P exam tomorrow!
@Azamspazam91 You almost confused me with your sarcasm, lol. Yep, I believe He exists too :)
@HoneiiDiiva Glad to hear. All the best on your exam. Let me know how it went!
@Elnora4ka You are very much welcome. Glad it helped :)
How can K+ only leave and never enter?
explained in an amazing and easy way its really a fun to study biology with such teacher
@ruddergrl1 I do not. All the best!
Excellent video- this was really helpful, thank you!
Very informative and to the point. Thank you
Thank you..that was amazingly simple.
Leslie? Are you like a biology teacher or something? Maybe you just a nerd. Whatever the case thank you so much sir! I can understand you spoof much more than my cardiac teacher. She might be a super smart retired dr. But, there is something to say a out someone like you that can actually make you understand . I love you voice too. It's soothing and intelligent sounding at the same time.
I like your series of videos but in this case, you really should explain how the Na+/K+ pump works in the pacemaker cell first to set up the potential gradient before the voltage sensitive K+ channels close while the Na+ is still pumped out. At this negative membrane potential, the Na+ starts to flow into the cell against the concentration gradient by diffusion, thus activating the potential of the cell which is the cause leading to -40mV where Ca+2 ions start flooding in.
You are an awesome individual to take the time to put all these videos. And you make it so simple and easy to understand without getting lost. Thanks MUCH!!
i have an exam tomorrow and this is great! :D
I was 8 years old then
U r legend for me who was
Of 16 17 years in 11th class.
Do you have any videos that are more specific with the mentioning of funny channels/T-type channels/L-type channels and when those, specifically, come into the picture, etc?
All these videos are great. Please keep them coming. You are making learning a lot easier!
This is like a skeletal muscles A.P?. Im a little confused my teacher was talking about funny channels, where does that come into the picture?
Doesn't the influx of calcium followed by the opening of voltage gated K channels result in a plateau ? I'm really confused - please help!
tnx we need more like u thanks so muchhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh so clearrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
I thought in phase 0 an HCN or nonselective channel causes a Na influx causing the prepotential .. and because it is nonselective K enters too as it is also positve.. also Ca T type channels contribute to this prepotential pushing it from -50 to -40 then both these channels are inactivated and Ca L type channels are activated causing an influx of Ca and depolarization
Bu what happened to the calciums that went inside the cell?
It's used to contract the muscles in muscle-contraction coupling!
It's used to activate cross bridge cycling, which activates muscle contraction! :)
great video, possible when the levels of serem in the r. atrium reach a point bridging the av node with the sa node , crossing the terminals with a temporary disconnect or a bigger pathway for current a spark(ark) is generated when on disconnect, possibly a gas is released by the nodes into the upper level of r. atrium when the level of rbc's reaches a high level point creates a bridge between the nodes igniting the gas creating combustion, can you measure concentrations in r. atrium
Great vids. BS in bio, prepping for PA school, love these videos. Really great physio refreshers.
Hi loved the video, is there any chance that this video is in spanish? I need it to present it in class, thanks!
The Calcium gate open before membrane reach threshold potential
not till reach threshold potential..
thank you very much . I had a big problem with understanding :)
so the Na keeps building up inside the cell and K keeps coming out? Where does it come from?
Wow. That was so unbelievably clear. Thanks for making such a complicated concept fun and so easy to understand!
You really save my an hour to Read the books and try to memorize
Thank youuuuu for making it simple and short! Awesome for cramming!
wow u are amazing!!!!!!! than you from those of us who have bad teachers!!
@1080portal ever heard of physicians? They do pretty well for themselves.
Why doesnt the SA node have a stable resting membrane potential?
amazing . thankyou . it was of great help .:)
you should come and teach in my university, one of my prfs sucks as
man you are the best in describing thank you
Very Perfect, Important and Systematic Points Bro Keep It Up👍👍 Superb Information and Organization.
Thank you very much, Tanishq Patil. I appreciate the compliment. My main goal here is to be helpful. If you haven't already, make sure to subscribe to the channel because I have a lot more content like this coming to help you understand how the human body works.
Does pacemaker cells use oxygen?
I am happy! Thank you for this!
Can supplementation with Potassium and Magnesium powder up to 4-5000 mg per day be helpful, if diet is only supplying 1000 mg per day, in improving conduction at the S-A node, which has been damaged due to subacute endocarditis, that damaged the node?
Thank you for the video - may I ask. You say Ca2+ flows into the pacemaker cell, but I was curious as to what happens to that calcium, as you didn't say it flows out again, surely it can't keep accumulating in the cell?
Thanks again!
since there's a higher concentration of K+ inside the membrane then outside, when K+ channels open, K+ will rush out because ions always move from higher concentrations to lower concentrations. The Na+/K+ pump then uses ATP to pump 2 K+ inside the membrane while pumping 3 Na+ outside so that a high concentration of K+ on the inside, and high concentration of Na+ on the outside will be maintained. This also makes the inside of the membrane negative again and return it to a resting potential.
Bunyi video tidak bagus
when potassium leaves a cell not all of it goes. Its only a percentage change that causes the impulse to occur. So during stages in-between stimulation the potassium does move back in and replenish.
sir I am currently at class 8 icse board India.. U haven't talked about the bundle of HIS above the purkenje fibers... pls note it
pls mark this
lesely ,, I wanna tell you something ,, you're really great
thanks so much
now I'm confused. I thought cells were more permeable/have a greater conductance for potassium. do pace maker cells not follow this dogma?
isn't the sodium being pump out and the potassium goes in? atleast that's how i think the sodium potassium pump work...i'm confused
this is SO BASIC , why dont you talk about funny channels and stuff ?
THANKS FOR THE XPLNN I REALLY LIKES UR XPLNTN
THANK YOU :) oh this helps me visually . I could not understand what contraction meant (i speak a different language) but seeing the first part now this really helps more than the text book and the lecture audio from my instructor
yes that's right.. because of the equilibrium
awesome video! Very helpful for y graduate course in cardiovascular physiology.
I don't understand, sodium ions just continuously pour in and potassium ions continuously rush out? That doesn't sound right...
+Kem syt
It may be helpful to look up L-type and T-TYPE tubules. These control the membrane potential of the cells of the SA nodes.
What happens to the sodium ions are they continuously getting inside making pacemaker cell depolerise or any moment they go outside
Why is the negativity of sinus node cell is less than the negatvity of the contactile muscle ???
I was taught that there are no functional Sodium ion channels in pacemaker cells, is this wrong?
@interactive biology does excitation contraction coupling start at the SA node?
I thought the Na+ channels in the SA node were inactivated...
+Raven Marshall They actually are since their activity is negligible, he probably doesn't understand the pacemaker activity quite well!
+Raven Marshall Or you could say that the depolarisation begins with the opening of the slow voltage-gated Na+ channel till it reaches the threshold where the fast Ca+ channels open and this what drives the depolarisation phase till it reaches its peak!
i read in a book that SA node produce action potential without stimulation.
how is it possible?
can any one answer me?
How sa node gets the energy..
purkyne tissue he said purkingy fibres ?
Thank u so much, Sir.
why is potassium leaving the cell all the time,, doesnt potassium ever come back into the cell ?
Thank you for your help. I'm a paramedic student and you broke down the depolarizing-repolarizing ion involvement very well for me to understand (we are currently beginning to analyze ECGs).
You are amazing!!!. Do you have any videos in which you explain the blood types and Rh factor?.