Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    5
    ReputationRep:
    What does the cell membrane of a neuron do?
    How does the myelin fatty sheath speed up the transmission?
    Offline

    16
    ReputationRep:
    The myelin sheath is made of schwann cells which help the electrical signal jumps gaps across the neuron (axon). Correct me if im wrong aha.
    • Thread Starter
    Offline

    5
    ReputationRep:
    (Original post by JaffaNeko)
    The myelin sheath is made of schwann cells which help the electrical signal jumps gaps across the neuron (axon). Correct me if im wrong aha.
    How does it help them jump from node to node? And do you know what is this sodium and potassium thing? Lol that makes no sense but I've read somewhere about the sodium and potassium ions moving but where does the sodium and potassium come from?
    Offline

    16
    ReputationRep:
    (Original post by Daydreamer3)
    How does it help them jump from node to node? And do you know what is this sodium and potassium thing? Lol that makes no sense but I've read somewhere about the sodium and potassium ions moving but where does the sodium and potassium come from?
    Hmm. Im sure there was something about ions but im not too sure. I got taught this stuff last year for my A&P exam, but thats as far as I can remember aha
    • Thread Starter
    Offline

    5
    ReputationRep:
    Bumpp....
    Offline

    18
    ReputationRep:
    (Original post by Daydreamer3)
    How does it help them jump from node to node? And do you know what is this sodium and potassium thing? Lol that makes no sense but I've read somewhere about the sodium and potassium ions moving but where does the sodium and potassium come from?
    helps with saltatory conduction, essentially letting the action potential jump from the end of one neurone to the next, speeding up the signal. the ions ( na+ and k+) are what create the action potential as the sodium potassium pump actively pumps out sodium and pumps in potassium, creating a reversal of charge relative to the surrounding area and this wave of depolarisation is how the action potential moves along neurones
    • Thread Starter
    Offline

    5
    ReputationRep:
    (Original post by glad-he-ate-her)
    helps with saltatory conduction, essentially letting the action potential jump from the end of one neurone to the next, speeding up the signal. the ions ( na+ and k+) are what create the action potential as the sodium potassium pump actively pumps out sodium and pumps in potassium, creating a reversal of charge relative to the surrounding area and this wave of depolarisation is how the action potential moves along neurones
    I didnt understand any of that but okay aha.
    What does it mean by the fatty sheath being insulating? Why does it need to be insulating ? In simple terms please, only doing GCSE
    Offline

    18
    ReputationRep:
    (Original post by Daydreamer3)
    I didnt understand any of that but okay aha.
    What does it mean by the fatty sheath being insulating? Why does it need to be insulating ? In simple terms please, only doing GCSE
    oh sorry nvm ignore that, the myelin sheath has two roles, speeding up the signal ( explanation above but you obv dont need to know at gcse ) and making sure the signal only travels in one direction.i think thats all you need to know for gcse
    • Thread Starter
    Offline

    5
    ReputationRep:
    (Original post by glad-he-ate-her)
    oh sorry nvm ignore that, the myelin sheath has two roles, speeding up the signal ( explanation above but you obv dont need to know at gcse ) and making sure the signal only travels in one direction.i think thats all you need to know for gcse
    How does it make it travel in one direction? And can you please explain the insulation part like why does it need to be insulated and what does that even mean?
    Offline

    11
    ReputationRep:
    (Original post by Daydreamer3)
    How does it help them jump from node to node? And do you know what is this sodium and potassium thing? Lol that makes no sense but I've read somewhere about the sodium and potassium ions moving but where does the sodium and potassium come from?
    Na+ ions move in at Na+ ion channels, either voltage gated or always open. The stimulus causes Na+ voltage gated ion channels to open at the start of the axon, which results in lots of Na+ ions moving in down their concentration and electrochemical gradient into the axon - these then cause the opening of voltage gated Na+ ion slightly further along the axon, which causes an influx on Na+ ions there, causing the opening of voltage gated Na+ ion channels slightly further along the axon, etc. until the end of the axon. In myelinated neurons, the voltage gated Na+ ion channels are at nodes of Ranvier, between stretches of the myelin sheath. These nodes mean the v-gated Na+ channels are much further apart than in non-myelinated cells, meaning the action potential "skips" the intermediate distances as the saltatory conduction loops are longer than in normal conduction loops.
    Also, the myelin sheath is non polar (being fats), so it repels charged species, like the organic anionic species inside the axon. Hence, the anions are less likely to attract the cations that are outside the neuron, and more likely to attract the ones inside, making lateral movement of ions (as in an action potential) more likely. This means you need less cations to depolarise the membrane (make it positive, usually +40mV).
    If you do physics, the myelin sheath reduces the transmembrane capacitance, as it means you need less charge for the same potential difference.

    Na+ and K+ come dissolved in water (as salts like NaCl) and food.
    Offline

    18
    ReputationRep:
    (Original post by h3rmit)
    Na+ ions move in at Na+ ion channels, either voltage gated or always open. The stimulus causes Na+ voltage gated ion channels to open at the start of the axon, which results in lots of Na+ ions moving in down their concentration and electrochemical gradient into the axon - these then cause the opening of voltage gated Na+ ion slightly further along the axon, which causes an influx on Na+ ions there, causing the opening of voltage gated Na+ ion channels slightly further along the axon, etc. until the end of the axon. In myelinated neurons, the voltage gated Na+ ion channels are at nodes of Ranvier, between stretches of the myelin sheath. These nodes mean the v-gated Na+ channels are much further apart than in non-myelinated cells, meaning the action potential "skips" the intermediate distances as the saltatory conduction loops are longer than in normal conduction loops.
    Also, the myelin sheath is non polar (being fats), so it repels charged species, like the organic anionic species inside the axon. Hence, the anions are less likely to attract the cations that are outside the neuron, and more likely to attract the ones inside, making lateral movement of ions (as in an action potential) more likely. This means you need less cations to depolarise the membrane (make it positive, usually +40mV).
    If you do physics, the myelin sheath reduces the transmembrane capacitance, as it means you need less charge for the same potential difference.

    Na+ and K+ come dissolved in water (as salts like NaCl) and food.
    gcse level
    • Thread Starter
    Offline

    5
    ReputationRep:
    "How does it make it travel in one direction? And can you please explain the insulation part like why does it need to be insulated and what does that even mean?"

    Someone answer this question please, google is useless unless you spend hours searching...
    Offline

    11
    ReputationRep:
    (Original post by glad-he-ate-her)
    gcse level
    FFS I keep posting without checking the level.
    • Thread Starter
    Offline

    5
    ReputationRep:
    (Original post by h3rmit)
    FFS I keep posting without checking the level.
    Lol, now please answer my question above !
    Offline

    18
    ReputationRep:
    (Original post by Daydreamer3)
    "How does it make it travel in one direction? And can you please explain the insulation part like why does it need to be insulated and what does that even mean?"

    Someone answer this question please, google is useless unless you spend hours searching...
    the answers to these questions is outside the scope of gcse as the explanation involves sodium voltage gated channels and nodes of ranvier to prevent propagation, at gcse you just have to accept that it insulates it, speeding it up and making it go in one direction
    • Thread Starter
    Offline

    5
    ReputationRep:
    (Original post by glad-he-ate-her)
    the answers to these questions is outside the scope of gcse as the explanation involves sodium voltage gated channels and nodes of ranvier to prevent propagation, at gcse you just have to accept that it insulates it, speeding it up and making it go in one direction
    Oh okay thank you! Unfortunately I don't revise that way and have to know why for everything..
    Offline

    11
    ReputationRep:
    (Original post by Daydreamer3)
    Oh okay thank you! Unfortunately I don't revise that way and have to know why for everything..
    Then my earlier answer will answer your second question
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    What newspaper do you read/prefer?
    Useful resources

    Study tools

    Rosette

    Essay expert

    Learn to write like a pro with our ultimate essay guide.

    Thinking about uni already?

    Thinking about uni already?

    See where you can apply with our uni match tool

    Student chat

    Ask a question

    Chat to other GCSE students and get your study questions answered.

    Creating

    Make study resources

    Create all the resources you need to get the grades.

    Planner

    Create your own Study Plan

    Organise all your homework and exams so you never miss another deadline.

    Resources by subject

    From flashcards to mind maps; there's everything you need for all of your GCSE subjects.

    Papers

    Find past papers

    100s of GCSE past papers for all your subjects at your fingertips.

    Help out other students

    Can you help? Study help unanswered threads

    Groups associated with this forum:

    View associated groups
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.