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In what direction does an action potential move in a nerve cell?
Wiki User
∙ 12y ago
originates in axon hillock. travels down axon to the target (i.e dendrite, another cell body, muscle fiber...)
Wiki User
∙ 15y ago
Wiki User
∙ 12y agoup to down
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What is the electrical signal carried by a nerve cell?
Action potential
In which direction does a nerve impulse usually move?
It's called the ACTION POTENTIAL, or, in the case of a myelinated axon, SALTATORY CONDUCTION.
In which direction do potassium ions flow as the action potential passes?
Out of the cell
Action potentials originate at the?
Action potentials are how nerve impulses are transmitted from neuron to neuron. An action potential is formed when a stimulus to the nerve cell causes the membrane to depolarize and open all of its sodium ion channels toward the threshold potential.
What does a conduction velocity of an action potential depend on?
An action potential does not have a conduction velocity. Rather, it makes sense to measure the conduction velocity of nerves or nerve cells and this is usually done in metres per second (m/s.). An action potential is characterised as "an all or none response". This means you cannot alter the characteristics of an action potential in a given nerve cell. If you get a nerve cell and manage to get it to threshold, produce and measure an action potential 1000 times or more at the exact same point on the cell, the action potential you measure will not change in timing or amplitude. Information travels down a nerve cell through action potentials. But it is not one action potential that travels the whole length of the axon. Instead what happens is that one action potential causes the next bit of the nerve cell to reach threshold and therefore creates an entirely new action potential. So you actually need multiple action potentials to happen along a nerve cell to send information down it. We call this "propagation of action potentials" since each action potential produces a new one. More properly, it is referred to as "saltatory action potential conduction". Conduction velocity is basically a measure of how quickly we can produce a series of action potentials to travel the distance of the nerve cell axon. Since action potentials only happen at each "Node of Ranvier", then the longer the distance between each node (internodal distance), the faster the conduction velocity of a nerve cell. Since the internodal distance is positively correlated with myelin thickness, more thickly myelinated nerve cells have faster conduction velocities. The thickest and fastest nerve cells are motor neurones and Ia fibres from muscle spindles with a diameter of 12-20 micrometres and a conduction velocity of 70-120 m/s. The thinnest/slowest are fibres used to convey slow pain (<1.5 micrometres and 0.5-2 m/s).
What is the electrical signal carried by a nerve cell?
Action potential
In which direction does a nerve impulse usually move?
It's called the ACTION POTENTIAL, or, in the case of a myelinated axon, SALTATORY CONDUCTION.
In which direction do potassium ions flow as the action potential passes?
Out of the cell
Action potentials originate at the?
Action potentials are how nerve impulses are transmitted from neuron to neuron. An action potential is formed when a stimulus to the nerve cell causes the membrane to depolarize and open all of its sodium ion channels toward the threshold potential.
Where is the hillock of the neuron?
The nerve cell hillock is the beginning of the axon immediately after the soma. This is where the action potential originates.
Do action potential cause electrical and chemical change in neuron?
Yes, you see when a action potential process is taking place the negative ions are in the center of the nerve and the positives are on the outside, during the action potential however they swap places, which in doing so changes the electrical and chemicals in the nerve cell.
What does a conduction velocity of an action potential depend on?
An action potential does not have a conduction velocity. Rather, it makes sense to measure the conduction velocity of nerves or nerve cells and this is usually done in metres per second (m/s.). An action potential is characterised as "an all or none response". This means you cannot alter the characteristics of an action potential in a given nerve cell. If you get a nerve cell and manage to get it to threshold, produce and measure an action potential 1000 times or more at the exact same point on the cell, the action potential you measure will not change in timing or amplitude. Information travels down a nerve cell through action potentials. But it is not one action potential that travels the whole length of the axon. Instead what happens is that one action potential causes the next bit of the nerve cell to reach threshold and therefore creates an entirely new action potential. So you actually need multiple action potentials to happen along a nerve cell to send information down it. We call this "propagation of action potentials" since each action potential produces a new one. More properly, it is referred to as "saltatory action potential conduction". Conduction velocity is basically a measure of how quickly we can produce a series of action potentials to travel the distance of the nerve cell axon. Since action potentials only happen at each "Node of Ranvier", then the longer the distance between each node (internodal distance), the faster the conduction velocity of a nerve cell. Since the internodal distance is positively correlated with myelin thickness, more thickly myelinated nerve cells have faster conduction velocities. The thickest and fastest nerve cells are motor neurones and Ia fibres from muscle spindles with a diameter of 12-20 micrometres and a conduction velocity of 70-120 m/s. The thinnest/slowest are fibres used to convey slow pain (<1.5 micrometres and 0.5-2 m/s).
Why is the term action potential used to describe a nerve impulse?
It is a difference in charge supplied by ion position. In resting potential the tendency is for the inside of the cell membrane to have a negative ionic charge, while the outside of the membrane has a positive charge. The change, back and forth in these two charge potentials is the conduction of charge down the neuron and is called the action potential.
How does a nerve cell make energy?
The part of the cell that produces energy varies between plants and animals. In plants, the energy producing part of the cell occurs in the chloroplast of the plant. In animals, the mitochondria produces the cells energy.
What is the electrical potential across the cell membrane of a nerve cell or muscle cell when the cell is not active?
resting potential
What are the major events of an action potential and what ion changes are associated with each event?
An action potential is a chain reaction of cell events caused by an ionic gradient. One example is the firing of a nerve reaction.
What is the name for the impulse generated when a neuron fires?
Brain send the message via nerve impulses involving neurons which use the neuro-transmitter AcetylcholineAcetylcholine- a neurotransmitter released at the neuromuscular junction triggers a muscle action potential, which leads to muscle contraction
