Neuroscience: Resting Neuron and Ion Movement
61 Questions
8 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the typical resting membrane potential (RMP) of a neuron?

  • -70 mV (correct)
  • -50 mV
  • -90 mV
  • 0 mV

    • Which ions have higher concentrations inside the neuron at rest?

  • Calcium (Ca2+) and Chloride (Cl–)
  • Magnesium (Mg2+) and Bicarbonate (HCO3–)
  • Potassium (K+) and Proteins (A-) (correct)
  • Sodium (Na+) and Chloride (Cl–)

    • What primarily drives the movement of ions across the neuron's cell membrane?

  • Electrochemical Gradients (correct)
  • Mechanical Force
  • Osmotic Pressure
  • Molecular Size

    • Which ions are primarily found at higher concentrations outside the neuron at rest?

    <p>Sodium (Na+) and Chloride (Cl–)</p> Signup and view all the answers

    What type of transport is required to stabilize ion concentrations for resting membrane potential?

    <p>Active Transport</p> Signup and view all the answers

    What is the function of the axon hillock in a neuron?

    <p>It initiates the action potential.</p> Signup and view all the answers

    How do action potentials travel along the axon?

    <p>They travel faster in axons with a larger diameter.</p> Signup and view all the answers

    What occurs in the synaptic cleft after an action potential?

    <p>Neurotransmitters are released from the presynaptic cell.</p> Signup and view all the answers

    What is true regarding the permeability of the neuronal membrane?

    <p>It allows selective ion movement through open channels.</p> Signup and view all the answers

    In what states can neurons exist?

    <p>Resting and active states are the primary states.</p> Signup and view all the answers

    What is the initial membrane potential of a neuron at rest?

    <p>-70 mV</p> Signup and view all the answers

    Which ion is primarily responsible for the depolarization of the neuron during an action potential?

    <p>Na+ (sodium)</p> Signup and view all the answers

    What mechanism allows action potentials to travel faster down myelinated axons?

    <p>Saltatory conduction</p> Signup and view all the answers

    What occurs after the depolarization phase in the action potential sequence?

    <p>Sodium channels close and potassium channels open</p> Signup and view all the answers

    How do neurotransmitters reach their target receptors in synaptic transmission?

    <p>Via vesicular release into the synaptic cleft</p> Signup and view all the answers

    What is the significance of reaching the threshold potential during an action potential?

    <p>It triggers the all-or-none response of an action potential.</p> Signup and view all the answers

    Which ion is primarily responsible for the repolarization phase following an action potential?

    <p>K+ (potassium)</p> Signup and view all the answers

    What role do the Nodes of Ranvier play in neuronal function?

    <p>They facilitate saltatory conduction of action potentials.</p> Signup and view all the answers

    What is the primary event that occurs at the axon hillock during the initiation of an action potential?

    <p>Voltage-sensitive sodium channels open as the threshold is reached</p> Signup and view all the answers

    During an action potential, which of the following correctly describes the ion movement?

    <p>Na+ is driven into the cell by both concentration and electrochemical forces</p> Signup and view all the answers

    Which characteristic distinguishes saltatory conduction from continuous conduction?

    <p>It jumps between Nodes of Ranvier via myelinated axons</p> Signup and view all the answers

    What is the significance of the term 'all-or-none' in the context of action potentials?

    <p>Once the threshold is reached, an action potential either occurs or does not</p> Signup and view all the answers

    Which type of axon would demonstrate faster conduction velocity?

    <p>Myelinated axon with a larger diameter</p> Signup and view all the answers

    What primarily drives the K+ ions out of the neuron during repolarization?

    <p>Electrochemical gradient favoring K+ movement outside</p> Signup and view all the answers

    What role do vesicles play in neurotransmitter function once an action potential reaches the synapse?

    <p>They store and release neurotransmitters into the synaptic cleft</p> Signup and view all the answers

    Which feature of neurons allows them to effectively transmit electrical signals over distance?

    <p>Voltage-sensitive channels opening sequentially along the axon</p> Signup and view all the answers

    What is the role of neurotransmitters after they are released into the synaptic cleft?

    <p>To bind to receptors on the postsynaptic neuron, initiating signaling</p> Signup and view all the answers

    Which neurotransmitter is primarily associated with muscle action and cognitive functions, particularly in relation to Alzheimer's Disease?

    <p>Acetylcholine</p> Signup and view all the answers

    What effect does too little norepinephrine have on mood and behavior?

    <p>It leads to depression</p> Signup and view all the answers

    Which statement accurately describes the role of glia in the central nervous system?

    <p>Glia provide nutrients and remove debris.</p> Signup and view all the answers

    Which neurotransmitter is considered majorly excitatory, promoting neuron firing and synaptic transmission?

    <p>Glutamate</p> Signup and view all the answers

    What is the primary function of dendrites in neuron structure?

    <p>Receive messages from other neurons.</p> Signup and view all the answers

    What is a consequence of Curare poison on neurotransmission?

    <p>It blocks acetylcholine receptors, leading to paralysis</p> Signup and view all the answers

    Which part of a neuron is primarily involved in directing the manufacture of proteins?

    <p>Soma</p> Signup and view all the answers

    What characteristic distinguishes neurons from glia in the central nervous system?

    <p>Neurons can fire action potentials.</p> Signup and view all the answers

    Which structural component of a neuron is characterized by a 'tree-like' structure with bumpy protrusions?

    <p>Dendrites</p> Signup and view all the answers

    How do glia contribute to neuron health and maintenance?

    <p>They guide neuron growth and remove debris.</p> Signup and view all the answers

    What percentage of cells in the central nervous system are composed of glia?

    <p>90%</p> Signup and view all the answers

    What primary role do axons have in neuronal function?

    <p>Transmit electrical impulses away from the cell body.</p> Signup and view all the answers

    Which function is NOT associated with glia?

    <p>Firing action potentials.</p> Signup and view all the answers

    Which component of a neuron contains structures necessary for its survival?

    <p>Soma</p> Signup and view all the answers

    What is primarily released into the synaptic cleft following the initiation of an action potential?

    <p>Neurotransmitters</p> Signup and view all the answers

    Which factor contributes to the speed of action potential transmission in axons?

    <p>Diameter of the axon</p> Signup and view all the answers

    What area of a neuron is specifically known as the site where action potentials are initiated?

    <p>Axon hillock</p> Signup and view all the answers

    Which type of proteins in the neuronal membrane are essential for ion flow?

    <p>Channel proteins</p> Signup and view all the answers

    What is the role of the synaptic cleft in neuronal communication?

    <p>To separate presynaptic and postsynaptic cells</p> Signup and view all the answers

    In what states do neurons operate, and why are both states important?

    <p>Resting and active; both states are essential for communication</p> Signup and view all the answers

    What characteristic of the neuronal membrane allows it to selectively permit ion passage?

    <p>Embedded channel proteins</p> Signup and view all the answers

    What primarily distinguishes myelinated axons from unmyelinated axons in terms of action potential propagation?

    <p>Myelinated axons exhibit saltatory conduction</p> Signup and view all the answers

    Which structure is NOT directly involved in the generation of an action potential?

    <p>Synaptic cleft</p> Signup and view all the answers

    What is the typical speed range for action potential transmission along an axon?

    <p>1 to 100 m/sec</p> Signup and view all the answers

    What is the primary characteristic of the neuron when it is at rest?

    <p>The inside of the neuron is electrically negative relative to the outside.</p> Signup and view all the answers

    Which process primarily allows ions to move across the cell membrane without the use of energy?

    <p>Diffusion</p> Signup and view all the answers

    What attracts negatively charged ions to positively charged ions in a neuron?

    <p>Electrostatic gradient</p> Signup and view all the answers

    What is true about the concentration of sodium (Na+) and chloride (Cl-) ions at rest in a neuron?

    <p>Na+ and Cl- ions have a higher concentration outside the neuron.</p> Signup and view all the answers

    What role do K+ ions play in stabilizing the resting membrane potential?

    <p>They contribute to the negative charge by being concentrated inside the cell.</p> Signup and view all the answers

    What is the effect of the active transport mechanism on ion concentration at resting potential?

    <p>It prevents the equal distribution of ions across the membrane.</p> Signup and view all the answers

    What occurs to ions when they diffuse across the neuron's cell membrane?

    <p>They move from high concentration to low concentration.</p> Signup and view all the answers

    What maintains the potential difference across the neuron's membrane at rest?

    <p>The presence of proteins with a negative charge.</p> Signup and view all the answers

    How do the electrochemical gradients affect ion movement into and out of a neuron?

    <p>They cause ions to move without any energy input.</p> Signup and view all the answers

    What is the typical resting membrane potential (RMP) observed in neurons?

    <p>-70 mV</p> Signup and view all the answers

    Study Notes

    The Resting Neuron

    • The inside of a neuron is negatively charged compared to the outside (-70 mV)
    • This is due to the uneven distribution of ions
    • The resting membrane potential is typically -70 mV
    • More Sodium (Na+) and Chloride (Cl-) ions are outside the cell
    • More Potassium (K+) and negatively charged proteins (A-) are inside the cell

    Ion Movement

    • Ions move across the membrane due to electrochemical gradients:
    • Diffusion: Ions move from high concentration areas to low concentration areas
    • Electrostatic Gradient: Opposites attract (positive ions attract negative ions)
    • These processes are passive, meaning they don't require energy.

    Active Transport

    • The movement of ions across the cell membrane requires energy (active transport)
    • Active transport stabilizes the ion concentrations for the resting membrane potential
    • Potassium ions (K+) are actively transported back into the cell
    • Sodium ions (Na+) are actively transported out of the cell

    The Active Neuron

    • Sodium (Na+) and Potassium (K+) channels exist in the membrane
    • When a neuron is at rest, the sodium channels are closed, and potassium channels are open.
    • When a neuron is activated, the sodium channels open, and potassium channels close.

    Reaching the Threshold

    • Depolarizing events trigger an action potential (when the cell reaches -50 mV)
    • Sodium channels open, sodium ions (Na+) rush into the cell, increasing the positive charge inside the cell
      • This is driven by concentration and electrochemical gradients
    • The cell becomes more positive (up to +30 mV)
    • Then, potassium channels open and potassium ions (K+) rush out of the cell
      • Again, this is driven by concentration and electrochemical gradients
    • The cell becomes more negative

    Action Potential Summary

    • Travel in one direction down the axon (from the axon hillock to the synapse)
    • Involves both active and passive processes
    • They are all-or-none events
      • Once the threshold is reached, the action potential will occur

    Saltatory Conduction

    • The action potential jumps from one Node of Ranvier to the next on myelinated axons
      • Node of Ranvier is a gap in the myelin sheath, where channel proteins are located.
    • Myelinated axons transmit action potentials faster than unmyelinated axons.

    Synapse

    • Synapses are the junctions between neurons
    • Neurons don't touch each other - they're separated by a small gap called the synaptic cleft
    • At the end of an axon (the presynaptic terminal)
      • Neurotransmitters are stored in vesicles
    • Once the action potential reaches the presynaptic terminal
      • Neurotransmitters are released into the synaptic cleft
    • The neurotransmitters bind to receptors on the postsynaptic membrane (the next neuron)
    • This initiates a response in the next cell

    ### The Axon

    • Most neurons have only one axon
    • Action potentials are generated at the axon hillock (where the axon joins the cell body)
    • Axon hillock is the area where the action potential starts
    • Action potentials travel between 1 to 100 m/sec
    • The larger the diameter of the axon, the faster the action potential travels

    Cell Membrane

    • The cell membrane is a lipid bilayer (thin layer of fat)
    • Proteins are embedded in the membrane
      • Channel proteins allow ions to pass through
      • Receptor proteins bind to neurotransmitters, signaling the cell
    • The membrane is selectively permeable
      • Some ions can pass through the channels when they are open

    Neuron States

    • Neurons can exist in two states:
    • Resting (inactive)
    • Active (firing)
    • Both states are equally important!

    The Active Neuron

    • The neuron at rest has an electrical charge of -70 mV.
    • This is due to the distribution of charged particles (ions) across the membrane.
    • The charge is maintained by an electrochemical gradient, which is driven by the concentration gradient and electrostatic gradient.
    • The electrochemical gradient is passive and does not require energy.

    Movement of Ions

    • The concentration gradient causes ions to move from an area of high concentration to an area of low concentration.
    • The electrostatic gradient causes ions to move from areas of opposite charge.

    Active Transport

    • The sodium-potassium pump actively transports ions across the membrane and requires energy.
    • This pump helps to maintain the resting membrane potential.

    Action Potential

    • If a depolarizing event occurs at the axon hillock and the threshold for initiating an action potential is reached (-50 mV), then an action potential will be triggered.
    • Voltage-sensitive sodium channels open, and sodium ions are driven into the cell by concentration and electrochemical forces.
    • Voltage-sensitive potassium channels open, and potassium ions are driven out of the cell by concentration and electrochemical forces.
    • The action potential travels in one direction down the axon.
    • The action potential is both an active and passive process.
    • The action potential is an all-or-none phenomenon, meaning that it either occurs at full strength or not at all.

    Myelination

    • Myelination allows for "saltatory conduction," where the action potential jumps from node of Ranvier to node of Ranvier.
    • This process is faster than conduction in unmyelinated axons.

    The Synapse

    • Neurons do not touch each other but are separated by a synaptic cleft.
    • When an action potential arrives at the terminal, neurotransmitters are released into the synaptic cleft.
    • These neurotransmitters bind to receptors on the postsynaptic cell, initiating events in the next neuron.

    Neurotransmitters

    • Neurotransmitters can excite (excitatory) or inhibit (inhibitory) the next cell.
    • Neurotransmitters are stored in vesicles, which are released into the synaptic cleft when an action potential arrives at the terminal.

    Different Types of Neurotransmitters

    • Acetylcholine: Muscle action, cognitive function, memory, and emotion.
      • Depletion of acetylcholine is associated with cognitive decline in Alzheimer's disease.
    • Dopamine: Voluntary movement, reward, learning, attention, and emotion.
      • Too much dopamine is associated with schizophrenia.
      • Too little dopamine is associated with Parkinson's disease.
    • Serotonin: Mood, hunger, sleep, and arousal.
      • Too little serotonin is associated with depression and seasonal affective disorder.
    • Norepinephrine: Heart rate, learning and memory, arousal, attention, waking, and emotion.
      • Too little norepinephrine is associated with depression.
    • GABA: Major inhibitory neurotransmitter.
    • Glutamate: Major excitatory neurotransmitter.
    • Endorphins: Opiate-like substances naturally released in response to fear, pain, exercise (runner's high), and chocolate.
      • Bind to opiate receptors.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Biological Basis of Behaviour (Part I) Ch3 PDF

    Description

    Explore the fundamental concepts of resting neurons, including membrane potential and ion distribution. Learn about the processes of diffusion, electrostatic gradients, and active transport that regulate ion movement across neuronal membranes. This quiz will test your understanding of these key neuroscience principles.

    More Like This

    Neural Membrane Ion Channels Quiz
    15 questions

    Neural Membrane Ion Channels Quiz

    WholesomeBalance avatar
    WholesomeBalance
    Neuron Resting Potential Quiz
    12 questions

    Neuron Resting Potential Quiz

    VictoriousLyre avatar
    VictoriousLyre
    Neuron Resting Potential and Gated Channels
    17 questions

    Neuron Resting Potential and Gated Channels

    FeistyTimpani avatar
    FeistyTimpani
    Neuron Resting Membrane Potential
    24 questions

    Neuron Resting Membrane Potential

    AdequateTucson avatar
    AdequateTucson
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser