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Most neurons are at a negative membrane potential so when a ligand operated channel opens there is an inflow of positively charged ions, mostly but not exclusively sodium. If the neuron cell membrane has voltage-operated channels (the textbook example) then the inflow of positive ions can open the voltage-operated channels causing an even greater flow of positive ions into the neuron. This positive feed arrangement can lead to the neuron transitioning from negative to respect to outside of the cell to positive (overshoot). Since the voltage-operated channels inactive and also due to the potassium specific channels the cell is returned it's pre-action potential negative level (close to potassium's equilibrium potential).
Wiki User
∙ 12y ago
Wiki User
∙ 13y agoLet's picture a presynaptic neuron, a synaptic cleft, and a postsynaptic neuron.
An action potential reaches the terminal of a presynaptic neurone and triggers an opening of Ca ions enters into the depolarized terminal. This influx of Ca ions causes the presynaptic vesicles to fuse with the presynaptic membrane. This releases the neurotransmitters into the synaptic cleft.
The neurotransmitters diffuse through the synaptic cleft and bind to specific postsynaptic membrane receptors. This binding changes the receptors into a ion channel that allows cations like Na to enter into the postsynaptic neuron. As Na enters the postsynaptic membrane, it begins to depolarize and an action potential is generated.
Wiki User
∙ 13y agoThe movement of positively charged particles into the neuron
Wiki User
∙ 11y agoThe dendrite, or dendritic spines.
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The greater influx of sodium ions results in what of the membrane?
depolarization
How does a neuron create a positive feedback loop?
through what can be seen as the domino effect. when depolarization opens sodium ion channel and that results to the opening of more sodium ion channels. this creates a positive feedback loop.
What is the functional unit of the nervous system?
The nervous system gathers information from the external environment, stores and processes it, and initiates the appropriate responses.__________________________________excuse me, i think he / she wasn't asking about what the nervous system is but what isThe functional unit of the nervous system is the neuron.
What process describe how signal travels from one end of a neuron to the other end?
Depolarization is not one of the answers. i am taking the same class. I'm nearly 100% sure it's C. Membrane excitability because they send information over long areas.
Opening sodium channels in the in the axon membrane causes?
Depolarization of the cell membrane. When the sodium channels open there is a rush of sodium ions down their concentration gradient into the cell. As they carry positive charge they reduce the potential difference (inside negative) across the membrane of the neuron.
What is depolarization of a neurotransmitter?
Depolarization stimulates the release of the neuro-transmitter from the terminal end of the neuron.
What event follows after the depolarization of a neuron?
A rapid return to the neuron's resting state
Opening of sodium channels in the membrane of a neuron results in?
depolarization.
Depolarization involves a neuron becoming?
becoming more positive
When the neuron is sussiciently stimulated this process and triggers the action potential?
depolarization
The crescent-shaped pacemaker of the heart that initiates depolarization under normal conditions is the?
Sinoatrial node
What event follow the depolarization of neuron?
Repolarization is after depolarization. It descends to a region of hyper polarization where it is more polar than resting membrane potential
What is The depolarization and repolarization of a neuron membrane called?
This process is called nerve conduction.
When the neuron is sufficiently stimulated this process occurs and triggers the action potential?
depolarization
State in which the resting potential is reversed as sodium ions rush into the neuron?
Depolarization
Which is the first step in a neuron production of an action potential?
Depolarization is the first event in action potential. During depolarization, the sodium gates open and the membrane depolarizes.
How is the resting potential different from repolarization?
Repolarization is when the cell or neuron returns to be more negative. Depolarization is when the cell or neuron becomes less and less negative.
