17 Questions
What is the electrical potential difference across the cell membrane known as?
Resting Membrane Potential (RMP)
What allows communication over short and long distances in excitable cells?
Action potentials (AP)
What increases the electrical force of attraction between ions?
The quantity of charge
What allows communication over short distances only in excitable cells?
Graded potentials (GP)
What is the potential difference across the membrane of a neuron?
~-70mV
Which type of ion channels respond to chemical stimulus such as neurotransmitters and hormones?
Ligand-gated channels
What type of ion channels respond to mechanical vibration or pressure stimuli?
Mechanically gated channels
What is the resting membrane potential of a non-conducting neuron?
~-70mV
What generates concentration gradients in neurons?
$Na^+$/K^+$ pumps
What are graded potentials confined to?
Small region of the plasma membrane
What determines the magnitude of transient changes in membrane potential?
Magnitude of the stimulus
What is the mechanism of action potentials (APs)?
Voltage-gated channels
What is the function of myelination in neurons?
Increase the speed of action potential propagation
Which factor affects the propagation speed of action potentials?
All of the above
What is the role of ion channels in generating large, rapid changes in membrane potential?
Generate local currents that depolarize adjacent regions
What is the function of saltatory conduction in myelinated neurons?
Reduce energy consumption during action potential propagation
What happens during depolarization in an action potential?
Membrane potential becomes more positive
Study Notes
Electrical Properties of Neurons
- The electrical potential difference across the cell membrane is known as the membrane potential.
- The membrane potential allows communication over short and long distances in excitable cells.
Ion Channels
- Ion channels that respond to chemical stimuli, such as neurotransmitters and hormones, are classified as ligand-gated ion channels.
- Ion channels that respond to mechanical vibration or pressure stimuli are classified as mechanosensitive ion channels.
Resting Membrane Potential
- The resting membrane potential of a non-conducting neuron is typically around -70mV.
Concentration Gradients
- Concentration gradients in neurons are generated by the sodium-potassium pump.
- The sodium-potassium pump is responsible for maintaining the concentration gradients of sodium and potassium ions across the cell membrane.
Graded Potentials
- Graded potentials are confined to the local region of the neuron where they are generated.
- The magnitude of transient changes in membrane potential is determined by the strength of the stimulus.
Action Potentials (APs)
- The mechanism of action potentials (APs) involves a rapid change in the membrane potential, resulting in a brief (millisecond-scale) reversal of the membrane potential.
- Action potentials are generated by the rapid opening and closing of voltage-gated ion channels.
Myelination
- The function of myelination in neurons is to increase the propagation speed of action potentials.
- Myelination allows for saltatory conduction, where the action potential jumps from node to node, increasing the speed of transmission.
Propagation Speed
- The propagation speed of action potentials is affected by the distance between nodes of Ranvier.
Ion Channels and Membrane Potential
- Ion channels play a crucial role in generating large, rapid changes in membrane potential, enabling the transmission of action potentials.
Depolarization
- During depolarization in an action potential, the membrane potential becomes less negative, moving towards a more positive value.
Test your knowledge of CNS physiology and electrical signals in neurons with this quiz. Learn about the movement of ions across the lipid bilayer, neuron resting membrane potential, maintenance mechanisms, and generation/propagation of signals.
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