0
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).
The depolarization of a neuron is initiated by the influx of positive ions, usually sodium ions, through ion channels in the cell membrane in response to a stimulus. This influx of positive ions causes the inside of the neuron to become less negative, leading to the generation of an action potential.
Let'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.
Add your answer:
Earn +20 pts
Opening of these channels leads to what of the motor endplate?
Opening of these channels leads to depolarization of the motor endplate, which triggers the release of neurotransmitters (such as acetylcholine) from synaptic vesicles. This initiates the muscle contraction process by activating the muscle fibers.
What are epsp?
EPSP stands for excitatory postsynaptic potential. It is a temporary depolarization of postsynaptic membrane potential caused by the flow of positively charged ions into the neuron, usually due to the binding of neurotransmitters to their receptors. EPSPs can help to trigger an action potential in the neuron.
When the outside of the neuron cell is more positive than the inside the cell is?
When the outside of the neuron cell is more positive than the inside, the cell is in a state of depolarization. This shift in electrical charge can trigger an action potential, leading to the propagation of nerve impulses along the neuron.
What is The region of a neuron with voltage-gated sodium channels?
The region of a neuron with voltage-gated sodium channels is the axon hillock. This is where action potentials are initiated in response to incoming signals. Sodium channels open in response to depolarization, allowing sodium ions to flow into the neuron and trigger an action potential.
An environmental stimulus acting on the body initially produces an electrical response called aan in the receptor neuron?
The electrical response in the receptor neuron is called an action potential. This action potential is generated when environmental stimuli cause depolarization of the neuron's membrane, allowing positive ions to enter and create a temporary change in electrical charge. This signal is then propagated along the neuron for further processing in the nervous system.
What is the rapid change in a membreanes potential cause by the depolarization of a neuron?
The rapid change in membrane potential caused by the depolarization of a neuron is known as an action potential. During depolarization, voltage-gated sodium channels open, allowing sodium ions to flow into the cell, causing the inside of the neuron to become more positive. This shift in charge initiates the action potential, which is essential for the transmission of electrical signals along the neuron.
When the depolarization reaches about -55 mV a neuron will fire an action potential?
Yes, this threshold is known as the neuron's resting membrane potential. When the depolarization reaches -55 mV, it triggers the opening of voltage-gated sodium channels, leading to the rapid influx of sodium ions and generating an action potential. This initiates the propagation of the electrical signal along the neuron.
Opening of sodium channels in the membrane of a neuron results in?
depolarization.
State in which the resting potential is reversed as sodium ions rush into the neuron?
This state is known as depolarization. It occurs when there is a rapid influx of sodium ions into the neuron, causing the inside of the neuron to become more positively charged compared to the outside.
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.
Depolarization involves a neuron becoming?
Depolarization involves a neuron's cell membrane potential becoming less negative, moving closer to zero. This occurs when positively charged ions flow into the cell, usually through ion channels, leading to an excitatory response in the neuron.
A wave of depolarization moves down the neuron?
A wave of depolarization occurs when there is a sudden influx of positive ions, typically sodium ions, into the neuron, leading to a reversal of the cell's membrane potential. This helps in transmitting electrical signals along the neuron through a process known as action potential propagation.
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 information transferred at the NMJ?
Information is transferred at the neuromuscular junction (NMJ) through the release of acetylcholine from the synaptic vesicles of the motor neuron. Acetylcholine binds to receptors on the muscle cell membrane, leading to depolarization and the generation of an action potential that initiates muscle contraction. The process is tightly regulated to ensure precise communication between the motor neuron and muscle fiber.
What has to be crossed before the neuron fires?
The threshold potential must be reached for the neuron to fire. This is the level of depolarization that triggers an action potential to be generated and propagated along the neuron.
