Great videos! You need to add a edit to the video because K+ is the most permeable ion to the resting membrane potential. Na+ is only slightly permeable to the resting membrane and Na+ tricking into the cell makes the cell just slightly more positive than it would be if only K+ flowed. Therefore, at resting membrane potential, the negative interior of the cell is due to much grater diffusion of K+ out of the cell than Na+ diffusion into the cell. :)
YOU ARE AMAZING!!!! I WISH THERE IS AN ANOTHER WORD. BUT YOU ARE JUST LITERALLY AMAZING. Thank you so much! Never found easy but you helped me so much and saved my time. Best wishes.
Sir you really should be awarded for making such awesome legible diagrams..which help us students form our own answers..and not just do copy pasting text from TB..literally the best teacher😄💯💯💯
Potassium is much more permeable than all those other ions. It is going against its electrical gradient, and so only a little bit will go out because of this, cause there is still negatively charged Cl- outside. However this tiny bit going against the electral gradient is enhanced because there is so much potassium inside the cell that it wants to move out against its concentration gradient. So instead of a tiny bit of potassium moving out, we have a few potassium moving out.
Great video. Some clarification on the establishment of the resting membrane potential: The Na/Ka-pump doesn't produce the cells resting membrane potential. It produces the electrochemical gradients that facilitates the movement of the ions across the membrane (and transport of other molecules across the membrane). What causes the resting membrane potential is the conductance or permeability (from the high number of potassium leak channels in the membrane) to potassium. This high permeability to potassium allows potassium to be the major contributor to the overall resting membrane potential, and since the equilibrium potential for potassium under physiological conditions is -90 mV, the resting membrane potential is accordingly close to this number, at around -70 mV.
Thank You sooo much. I am taking A&P right now and I am currently learning about the nervous system. Your video helped me understand this potential more completely.
NaK-ATPace doesn’t have much role in action potential - it doesn’t have to. For example: amount of sodium inside cell is measured in mmol - ion channels (within ms) lets some picomole inside. Also ATPaces capacity is rather low on transporting ions. One thing is easily forgotten - diffusion of ions, when they enter in or out cells. The ions doesn’t stay in place for long - ask mr. Brown :). It’s the flux of potassium that in the end makes resting potential to recover. Check Ouabain studies on nervous system. Doc
Sorry, just to clear up, does the Na+/K+ pump create a small electrical gradient that is made stronger by the diffusion of K+ ions, or is the electrical gradient only down to the diffusion of K+ ions? My text books say the latter, but I somehow think that's wrong.
What I don't understad is: you say K+ continue to go outside, even when their koncentration both in ICF and ECF is even. But how, when those big Anions inside the cell attract those Positive K+, that are already outside?
All information I have ever read has always stated that the flow of Sodium through leaky channels is low and the flow of K+ ions through leaky channels is high. This means you have very few sodium ions moving in and more k+ moving out. This net flow of electrical charge out in conjunction with the Na+/K+ channel causes the -70 mv difference across the membrane. ????
Why does the potassium still want to go out of the cell? Its going agains its electrical gradient right? Potassium is positively charged but still diffuses to the outside which is positively charged? Why doesnt it want to stay inside where its negatively charged?
I am really struggling on this topic. my teacher didn't teach like you. He makes feel feel so stupid in the class. He didn;t draw any picture. He just tell us the 10 steps of the resting potential. I ask him question in the class. He just said it writen on the board. I was so upset and now I am really struggling. He expect us to have exam soon. and i am not understand at all. can you help please
this is not correct..because under resting condition..voltage gated Na channels is closed so no net movement of sodium in or out the cell inspite of its electrochemical gradient to go from out to in.. !
i got the part that potassium move out due to concentration gradient.but why potasium move out due to the electrical gradient , if the protein is so negatively charged inside , ?
1. how the voltage gated channels (Na+) open at the time of stimulus for depolarization. 2. how the next site of depolarized site starts showing the depolarization for the conduction of nerve nerve i,e gets depolarized. 3.which causes the breaking of synaptical vesicles in the synaptic button.
i had so much problems with understanding how the cell maintain its resting membrane potential i watched alot of videos and lectures,,,but i did not understand it thanks to u clearing some small but very important key points making it easy to understand u r the best :* very grateful :)
why does "K+ surprisingly move out of the cell" due to the electrical gradient at 7:17? Seeing its positively charged why would it want to move out to a positive charge?
Hi Armando! Your videos are such a great help for visual learners like myself. I am wondering if you sell or provide downloads of the final images so we can use them when studying and during lecture? I am in NP school studying pharmacology now. Thank you!
your vedio is so great! Excellent illustration! It helps me a lot! Would you please make another vedio on action potential? I'm looking forward to your lecture!:)
Draw equations containing slopes, gradients and coordinates? Google has plenty electrical schematics and graphs that represent bio-electrical circuits. So, you just like to hear yourself talk. Jesus fuckin' Christ on pogo stick, why can't people just say "thanks", or STFU.
