Ionic basis of action potential curve physiology | Nervous system physiology mbbs 1st year

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Physiology Open

Күн бұрын

Пікірлер: 45

@asaphsalmon9383 2 жыл бұрын

Thanks for the lecture maam...i have my exam in 2 hours and this helped a lot😂💯

@PhysiologyOpen 2 жыл бұрын

Could you write this if it was there?

@Dr.AnnaduraiS Жыл бұрын

Madam, very nice explanation. However, there are two corrections. Firstly, the channel that causes local or graded potential is ligand-gated channels (in some tissues by mechanosensitive channels), Not by the opening of a few voltage-gated channels. As I understood, voltage-gated channels will open only when the local potential reaches the firing level. Secondly, it was mentioned that sodium entry is by facilitated diffusion (facilitated diffusion can be operated only through the carrier, not by the channels) it is only by simple diffusion. Thank You.

@PhysiologyOpen Жыл бұрын

Thanks for liking. However, I do not agree with the first correction with respect to neuron The video is on action potential of neuron which generates at axon Hillock and the stimulus is voltage change coming from dendrites (at dendrites the voltage change occurs due to ligand gated channels) . However as the grades potential travels, it causes local voltage change by electro tonic conduction and very few voltage channels in nearby areas in neuron For facilitated diffusion, Guyton mentions channels as part of simple diffusion. However all textbooks on cell biology mention it as part of facilitated diffusion. By definition, simple diffusion occurs through lipid bilayer . It doesn’t require any transport protein including channel proteins

@Plizz-PlizzJr Жыл бұрын

Clearly explained 🤝🏾thnk u mam😊

@PhysiologyOpen Жыл бұрын

My pleasure

@riteshchaurasia4953 3 жыл бұрын

Is depolarization is time bound only or voltage too..when does depolarization stop/n at what voltage level n what factors regulate it..what happens to cell if exact value of depolaizationmis not reached..

@PhysiologyOpen 3 жыл бұрын

The magnitude of depolarization is depedent on the concentration difference of ions inside and outside the cell and the duration for which the channels are open. We can understand it in terms of what will be the membrane potential if particular ions are free to move..e.g. when cell is in resting state membrane is permeable mainly to potassium ions so..RMP value is decided by mainly concentration difference of potassium ions across the cell membrane and membrane permeability to potassium ions (see the video on resting membrane potential) In action potential, membrane becomes permeable to sodium ions also..so membrane voltage depends on potassium ion permeability as well as sodium ion peremability and their concentration differences across cell membrane..

@PhysiologyOpen 3 жыл бұрын

what happens to cell if exact value of depolaization is not reached? If depolarization is not reached to say suppose +20 mv but remains to + 10 mv...it is still an action potential...however since this action potential propagates and ultimatelu causes opening of voltage gated calcium channels in nerve terminal...the number of channels which open due to voltage change may be little lesser...

@isit1707 3 жыл бұрын

@@PhysiologyOpen thanks a lot 🙏 In this you tube channel even in comments we can extract the knowledge 🤓💫🤩

@PhysiologyOpen 3 жыл бұрын

😊...so nice to know that..thanks and welcome

@R.Bharathkumar2003 2 жыл бұрын

@@PhysiologyOpen mam is it still said to be satisfying the all or none law? As it is only giving +10 but not +20mv.Is it even possible that a nerve getting excited partially like In this case the nerve exciting only upto 10mv but not to it's full potential(20mv)?

@drkpradeepkumar9972 3 жыл бұрын

Nicely explained

@PhysiologyOpen 3 жыл бұрын

Thanks

@nithinkrishna9861 3 жыл бұрын

Important concept

@PhysiologyOpen 3 жыл бұрын

Yup

@muhammadimrannasib8935 9 ай бұрын

Very important most of the doctors and student dont know especially role of Na k pump

@Shravansahu21 5 ай бұрын

Great explanation❤

@PhysiologyOpen 5 ай бұрын

Glad it was helpful!

@safa4968 15 күн бұрын

Thank you 🫶🏻

@PhysiologyOpen 15 күн бұрын

Most welcome

@sravanidevsur7430 2 жыл бұрын

Superb mam

@PhysiologyOpen 2 жыл бұрын

Thanks

@abielamulya2340 Ай бұрын

Mam can we have excitation and conduction, measurement of electrical events

@PhysiologyOpen Ай бұрын

Strength duration curve for measurement of excitation... I have a video ..you may watch that Nerve conduction velocity for measurement of conductivity