How do nerves work? – Elliot Krane

How do nerves work? – Elliot Krane


How do nerves work? Are nerves simply the wires in the body that conduct electricity, like the wires
in the walls of your home or in your computer? This is an analogy often made, but the reality is that nerves have
a much more complex job in the body. They are not just the wires,
but the cells that are the sensors, detectors of the external
and internal world, the transducers that convert
information to electrical impulses, the wires that transmit these impulses, the transistors that gate the information and turn up or down the volume- and finally, the activators
that take that information and cause it to have
an effect on other organs. Consider this. Your mother
gently strokes your forearm and you react with pleasure. Or a spider crawls on your forearm
and you startle and slap it off. Or you brush your forearm against a hot
rack while removing a cake from the oven and you immediately recoil. Light touch produced
pleasure, fear, or pain. How can one kind of cell
have so many functions? Nerves are in fact bundles
of cells called neurons and each of these neurons is highly
specialized to carry nerve impulses, their form of electricity, in response to only one kind
of stimulus, and in only one direction. The nerve impulse starts with a receptor, a specialized part of each nerve, where the electrical impulse begins. One nerve’s receptor might
be a thermal receptor, designed only to respond to a rapid
increase in temperature. Another receptor type is attached
to the hairs of the forearm, detecting movement of those hairs, such
as when a spider crawls on your skin. Yet another kind of neuron
is low-threshold mechanoreceptor, activated by light touch. Each of these neurons then carry
their specific information: pain, warning, pleasure. And that information is projected
to specific areas of the brain and that is the electrical impulse. The inside of a nerve is a fluid
that is very rich in the ion potassium. It is 20 times higher
than in the fluid outside the nerve while that outside fluid has 10 times
more sodium than the inside of a nerve. This imbalance between sodium
outside and potassium inside the cell results in the inside of the nerve
having a negative electrical charge relative to the outside of the nerve, about equal to -70 or -80 millivolts. This is called
the nerve’s resting potential. But in response to that stimulus
the nerve is designed to detect, pores in the cell wall
near the receptor of the cell open. These pores are specialized
protein channels that are designed to let
sodium rush into the nerve. The sodium ions rush
down their concentration gradient, and when they do, the inside of the nerve
becomes more positively charged- about +40 millivolts. While this happens, initially
in the nerve right around the receptor, if the change in the nerve’s electrical
charge is great enough, if it reaches what is called threshold, the nearby sodium ion channels open,
and then the ones nearby those, and so on, and so forth, so that the positivity spreads
along the nerve’s membrane to the nerve’s cell body and then along the nerve’s long,
thread-like extension, the axon. Meanwhile, potassium ion channels open, potassium rushes out of the nerve, and the membrane voltage
returns to normal. Actually, overshooting it a bit. And during this overshoot, the nerve is resistant to further
depolarization-it is refractory, which prevents the nerve electrical
impulse from traveling backwards. Then, ion pumps pump the sodium
back back out of the nerve, and the potassium back into the nerve, restoring the nerve to its
normal resting state. The end of the nerve, the end of the axon, communicates with the nerve’s target. This target will be other nerves
in a specialized area of the spinal cord, to be processed and then
transmitted up to the brain. Or the nerve’s target may be
another organ, such as a muscle. When the electrical impulse
reaches the end of the nerve, small vesicles, or packets, containing
chemical neurotransmitters, are released by the nerve and rapidly
interact with the nerve’s target. This process is called
synaptic transmission, because the connection between the nerve
and the next object in the chain is called a synapse. And it
is here, in this synapse, that the neuron’s electrical
information can be modulated, amplified, blocked altogether or translated
to another informational process.

100 Replies to “How do nerves work? – Elliot Krane”

  1. Since I'm currently a little bit bored, I will go on. Please notice that I corrected you, that means that I understood what you've said; on the other hand, you didn't understand that I did, therefore you are the retarded one. 🙂

  2. But during those reflexive actions, you are not even aware yet, that you have pain or fear. That emotional part comes in only later.
    Of course, you can feel pleasure like that but I assumed here that you are to some degree aware of the dangers. I assumed a person you do not like. Wether you like a person or not is processed entirely differently than wether you're touched somewhere somehow. Only both informations together give the actual emotional reaction.

  3. If your truest question is whether or not we evolved or if we were created, than probability and complexity are incoherent questions. Evolution doesn't subscribe itself to mere chance according to the evolutionary biologist Richard Dawkins. Meaning evolution didn't and doesn't occur through randomization of mutations or genetic dispositions. Rather the occurrence through evolution is specified through the utmost compatible charaicterists of usefulness evolving from unusefullness.

  4. i agree.. can u explain to me how the evolution process of unusefulness into usefulness according to the latest theories..? what makes me curious is.. just thought that this 'neuron thing' is a system.. and a system cant work when one parts of it missing.. then this 'neuron thing' must come with an already complete structure in order to work.. then, how it done..?

  5. You should stick to religions normal stance of denying every thing that has to do with science, at least then you can just say you think they're lying, instead of trying to twist their own discoveries.

  6. i think science is supporting constant action of searching and questioning.. is there any flaw in my argument..? i believe they're not lying.. fyi: my religion is supporting science – first revelation was an order to read, read, and read..

  7. You are exactly right….. No matter how much atheists try to make themselves look smart, saying that we (magnificently and unfathomly complex) Humans, came from absolutely nothing (just random atoms) shows that they're in plain denial of the fact that we were created.

  8. Exactly… Science supports the existence of a creator no matter how you look at it. From the fact that something cannot come from nothing (i.e. what was before the big bang?), to the complexities of the universe itself, and on both superficial and microscopic levels, the complexity of humans and life itself… that is if you use your common sense, which god provided to us inertly in order to recognise him.

  9. Well it depends on what you perceive to be evidence for a creator. For me, videos like this provide enough evidence for belief in a god, as it seems logical that these systems, which are so infinitely complex, cannot possibly come through random processes and mere chance. But hey, you come across as a person who just wants to debate, and if that's the case, I honestly cannot be bothered. So let's just leave it at having two different perspectives on the origins of life.

  10. What he meant in this presentation, is that "actually" the impulses that run through the neural network after being transmitted by receptors are made of wibbly wobbly stuff that turns into icky squishy stuff when it encounters an orgran(that isn't necessarily squishy).

  11. Twas a joke. Jesus was a man 2000 years ago thought to have superhuman powers. He didn't, but many people still think he did, largely because they didn't and/or don't have access to information like via this video. These people think that jesus can affect their physical bodies posthumously through a magical practice called prayer. That isn't what's happening. If one feels a tingling sensation while praying, it's your nerves.

  12. I think it's important to note that the Sodium/Potasium pumps are working constantly and don't just turn on. They're used to maintain the concentration gradient by pumping out 3Na molecules for every 2K molecules pumped in.

  13. Perfect review of the action potential of a neuron. I really did enjoy this. It made me remember everything I learned from class too.

  14. apparently little jesus-people run within your body, carrying information with bare hands and pulling on strings.

  15. Wonderful video clip. I had been so mystified seeing my best mate go from being lame to a ladies man. He began attracting women magically. He pretended he failed to notice. Then he explained it to me when he was drunk. Turns out he uses the Jake Ayres Master Attraction Formula. Google it and you'll find it… He is on a date right now with a sexy girl… Lucky dick!

  16. Well, that cleared some stuff up. . .
    Here I was thinking that ion pumps operated when the nerve fired, not to exert the work of rebounding the nerve back to its resting state. But the more I think about it, the more sense that makes.

  17. Life sucks. My buddy has started seeing a ten because 8 weeks ago he registered to an internet site called Master Attraction (Google it if you desire to learn more.) I'm jealous because I want to fall in love as well. I'm gonna take a peek at this Jake Ayres man's emails to find out if it might help a person like me. Bizarre thing is, he previously had Zero luck with women. How can you change that rapidly? His lady's a fucking model!

  18. Thanks a ton for the polarisation process 🙂 I literally had been banging my head around for straight 4 hours.

  19. There are 86 billion nerves in my brain, and there's always that one person who just seems to get on every single one of them

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