0
When the summed total of all post synaptic potentials rise above threshold creation of action potentials occur?
Wiki User
∙ 9y agoWant this question answered?
Be notified when an answer is posted
Add your answer:
Earn +20 pts
What is the difference between action potentials and synaptic potentials?
A synaptic potential exists at the INPUT of a neuron (dendrite), and an action potential occurs at the OUTPUT of a neuron (axon). (from OldGuy)(from Ilantoren:) A synaptic potential is the result of many excitatory post synaptic potentials (epsp) each one caused by the synaptic vesicles released by the pre-synaptic terminus. If there are enough of these epsp then the responses will summate and depolarize the post-synaptic membrane at the axon hillock enough to fire an action potential.
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 is the difference between local potential and action potential?
Local Potentials: Ligand regulated, may be depolarizing or hyperpolarizing, reversible, local, decremental Action Potentials: Voltage regulated, begins with depolarization, irreversible, self-propagating, nondecremental.
What is the basic structure of a neuron?
A neuron consists of three major parts: The dendrites, cell body, and axon. Most, though not all, axons are covered with myelin sheath which is made up of glial cells. The ends of axons are further divided into axon terminals. The axon terminal of one neuron and the dendrites of another is separated by the synaptic cleft.
What determines if an action potential is initiated in the postsynaptic neuron?
Every time neurotransmitter is released from the presynaptic neuron it generates an excitatory post synaptic potential(EPSP) in the postsynaptic neuron. When the EPSP is greater than the threshold for excitation an action potential is generated.
A common feature of action potentials?
They are triggered by a depolarization that reaches the threshold
Spontaneous firing rate of a neuron?
a periodic production of action potentials even without synaptic input
What is the difference between action potentials and synaptic potentials?
A synaptic potential exists at the INPUT of a neuron (dendrite), and an action potential occurs at the OUTPUT of a neuron (axon). (from OldGuy)(from Ilantoren:) A synaptic potential is the result of many excitatory post synaptic potentials (epsp) each one caused by the synaptic vesicles released by the pre-synaptic terminus. If there are enough of these epsp then the responses will summate and depolarize the post-synaptic membrane at the axon hillock enough to fire an action potential.
What EPSPs will summate to a sustained value above threshold?
Generate a string of action potentials
What happens after nerve signal reaches a synaptic knob?
In general, action potentials that reach the synaptic knobs cause a neurotransmitter to be released into the synaptic cleft. The arrival of the action potential opens voltage-sensitive calcium channels in the presynaptic membrane.
What is the association of axons with nerves?
Axons conduct the nerve impulses, or action potentials, to the axon terminals and the synaptic cleft.
Describe the general structure of a synapse?
Synapses occur between two neurons. Electrical activitiy in the pre-synaptic neuron influences the post-synaptic neuron. There are two types of synapses in the body: Electrical and chemical. Electrical synapses occur in pre and post synaptic neurons that are joined via gap junctions. Currents from action potentials flow across the junction through channels called connexons. This current will depolarize the membrane of the post synaptic neuron to threshold, which will continue the action potential in the cell. Electrical synapses are fast and bidirectional. However, they are mainly found in cardiac and smooth muscles, and not in the mammalian nervous system.Chemical synapses use neurotransmitters. Depolarization occurs in the pre-synaptic neuron and calcium ions rush in. The calcium ions activate neurotransmitter release into the synaptic cleft. The neurotransmitters reach the post-synaptic neuron and cause action potentials to develop.Note: this can go into much more detail
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.
The all or none principle states that?
The all-or-none principle in physiology states that once a nerve impulse reaches a certain threshold, a neuron will fire at its maximum potential. If the stimulus is strong enough to trigger an action potential, the response will occur at full strength. If the stimulus is below the threshold, no response will be triggered.
What is the difference between local potential and action potential?
Local Potentials: Ligand regulated, may be depolarizing or hyperpolarizing, reversible, local, decremental Action Potentials: Voltage regulated, begins with depolarization, irreversible, self-propagating, nondecremental.
What is the difference between a compound action potential and a single action potential?
Single action potentials follow the "all or none" rule. That is, if a stimulus is strong enough to depolarize the membrane of the neuron to threshold (~55mV), then an action potential will be fired. Each stimulus that reaches threshold will produce an action potential that is equal in magnitude to every other action potential for the neuron. Compound action potentials do not exhibit this property since they are a bundle of neurons and have different magnitudes of AP's. Thus compound action potentials are graded. That is, the greater the stimulus, the greater the action potential.
What has the author John H Byrne written?
John H. Byrne has written: 'An introduction to membrane transport and bioelectricity' -- subject(s): Action potentials (Electrophysiology), Biological transport, Cell Membrane, Electrophysiology, Membrane Potentials, Physiology, Synaptic Transmission 'Learning and Memory'
