0
What is a sub-threshold change in membrane potential within the cell body that decays as it travels away from its point of origin?
Wiki User
∙ 15y ago
synaptic/graded potential
Wiki User
∙ 15y ago
Add your answer:
Earn +20 pts
What is the small change in the charge across a neuron's membrane called?
Action Potential
What cell membrane do action potentials travel along?
The membrane or resting potential is the difference in voltage within and outside the cell when that cell is at rest. In a typical neuron it is usually around -65mV, meaning the neuron is negatively charged relative to the extracellular space. This potential is due to various ions and the permeability of the neuronal membrane. When a neuron gets a signal from another neuron, this causes the concentration of various ions to change (some flow in, others out of, the cell). In some cases, the signal causes positive ions to flow into the cell, making the membrane potential less negative. Once it reaches a threshold, usually around -55mV, the cell "fires" or makes an action potential, which is when the membrane potential temporarily shoots up to around +40mV. This signal propagates down the length of the neuron and then passes that message on to other cells.
What is the Difference between a receptor and an action potential?
action potential has a threshold stimulus and depolarization is just change in membrae potential where inside becomes for positive relative to outside. The AP has the ability to actually transmit info over long distance in axons once threshhold stimulus/depolarization is reached
Period during which potassium ions diffuse out of the neuron due to a change in membrane permeability?
Membrane potential - a nerve cell set and ready to fire;"The wave of reverse polarity" i.e. sodium versus potassium trans-cell-membrane ion passaging - a nerve cell firing; andRecharge period - the regeneration time.
What effect does potassium have on the resting potential of a cardiac cell?
Hyperkalemia is an increase in extracellular K. Driving force of an ion depends on two factors, voltage and concentration gradient. For K voltage gradient is pushing K into the cell but the concentration gradient is driving K out of the cell. However, the total driving force for K is out of the cell because the concentration gradient is that strong. When there is an increase in K on the outside, the driving force for K decreases.The equilibrium potential for K is -95mV. This means if K was freely permeable to the cell's membrane, it would reach equilibrium at -95mV. Another way to look at this is that efflux of K is the same as influx of K and the cell's new resting membrane potential would increase from a normal value of -70mV to -95mV. Note that I said it would increase even though the value became more negative. This is because the change in membrane potential has increased.Since the driving force of K has decreased, the equilibrium potential has also decreased. From a value of -95mV it is decreased to let's just say -80mV. Since a normal resting membrane potential is regularly -70mV, the decrease in equilibrium potential of K has decreased this resting membrane potential to say -60mV now. This is a depolarization of the cell.If this process happens quickly, it will depolarize the cell to the threshold value and you will have an action potential. However, if the hyperkalemia is severe, the cell will stay depolarized because the K equilibrium has decreased to a point where the cell cannot hyperpolarize back to threshold or resting membrane potential.If this process happens slowly, the inactivation gates of the sodium voltage-gated channels will automatically shut and the cell cannot depolarize even if it reaches threshold values. It must hyperpolarize back to resting membrane potential and the inactivation gates of the sodium voltage-gated channel will reopen.
What is local response?
Local responce is a small change in membrane potential caused by a subthreshold stimulus.
What change in membrane potential triggers action potential?
depolarization
What change in membrane potential depolarization or hyperpolarization triggers an action potential?
despolarization
What is the rapid change in membrane's potential caused by the deplariztion of a neuron?
action potential
A series of similar stimuli that increases change in local membrane potential is called?
Action potential
What change in membrane potential triggers an action potential?
An ion channel.
What cause the membrane potential of a neuron?
Opening or closing of ion channels at one point in the membrane produces a local change in the membrane potential, which causes electric current to flow rapidly to other points in the membrane.
When a stimulus is sufficiently great enough to change the membrane potential and propagate an action potential it is called?
recruitement
What is the small change in the charge across a neuron's membrane called?
Action Potential
An action potential is a travelling change in the axon's membrane permeability resulting in a flow of?
ions
What technique can be used to measure cell activity like a change in membrane potential?
it is patch lamp
Which ion channels open in response to a change in membrane potential?
voltage-gated ion channels
