NURS 207: Nervous System Basics
65 Questions
0 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 primary function of microtubules in neurons?

  • To provide structural integrity to the cell body.
  • To facilitate intracellular transport. (correct)
  • To generate neurotransmitters.
  • To conduct electrical signals.

    • What are dendrites primarily responsible for in a neuron?

  • Creating the myelin sheath surrounding the axon.
  • Sending outgoing signals to target cells.
  • Receiving incoming information from neighboring cells. (correct)
  • Housing the nucleus of the neuron.

    • Which part of the neuron is responsible for processing and integrating signals?

  • Dendrites
  • Myelin sheath
  • Cell body (correct)
  • Axon

    • What is the role of the myelin sheath in neuronal function?

    <p>To increase the speed of signal transmission.</p> Signup and view all the answers

    The synapse is best described as what?

    <p>The region where a neuron communicates with its target cell.</p> Signup and view all the answers

    What is the primary function of sensory neurons?

    <p>Convey information to the CNS</p> Signup and view all the answers

    Which structure characterizes all motor neurons?

    <p>Multipolar structure</p> Signup and view all the answers

    What type of neuron is primarily responsible for integrating sensory information within the CNS?

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

    Where are the dendrites of sensory neurons typically located?

    <p>Near sensory receptors</p> Signup and view all the answers

    What does the axon hillock of a neuron do?

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

    What are motor neurons also referred to as?

    <p>Efferent neurons</p> Signup and view all the answers

    Which term describes neurons that have no axon?

    <p>Anaxonic neurons</p> Signup and view all the answers

    What part of the neuron is primarily involved in receiving input signals?

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

    What is the role of the myelin sheath in neurons?

    <p>To protect and insulate axons</p> Signup and view all the answers

    Where does synaptic communication take place in a neuron?

    <p>At the axon terminal</p> Signup and view all the answers

    What role do motor proteins play in axonal transport?

    <p>They facilitate the movement of vesicles along microtubules.</p> Signup and view all the answers

    Which of the following describes retrograde fast axonal transport?

    <p>Transport of materials from the axon terminal to the soma.</p> Signup and view all the answers

    What provides the energy source for the movement of motor proteins?

    <p>ATP.</p> Signup and view all the answers

    What process allows synaptic vesicle contents to be released?

    <p>Exocytosis.</p> Signup and view all the answers

    Which statement correctly describes a typical neuron?

    <p>Neurons transmit graded potentials from dendrites to the axon hillock.</p> Signup and view all the answers

    What happens during the walking mechanism of motor proteins?

    <p>They alternately bind, release, and step forward along the microtubules.</p> Signup and view all the answers

    What is a characteristic of axons in neurons?

    <p>They are specialized to carry electrical signals unidirectionally.</p> Signup and view all the answers

    How do lysosomes contribute to axonal transport?

    <p>By digesting old membrane components.</p> Signup and view all the answers

    What triggers action potentials in neurons?

    <p>Graded potentials reaching the axon hillock.</p> Signup and view all the answers

    What primarily prevents the free movement of ions between the intracellular and extracellular compartments?

    <p>Plasma membrane</p> Signup and view all the answers

    Which of the following ions has a higher concentration in the extracellular fluid compared to the intracellular fluid?

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

    What is the net effect of the Na+-K+ ATPase on intracellular ion concentration?

    <p>Increase K+ concentration while decreasing Na+ concentration</p> Signup and view all the answers

    What contributes to the generation of resting membrane potential?

    <p>Differential permeability to K+ compared to Na+</p> Signup and view all the answers

    What happens to K+ ions due to concentration gradients across the plasma membrane?

    <p>They leak out to the extracellular space.</p> Signup and view all the answers

    How does the unequal distribution of ions contribute to resting membrane potential?

    <p>It creates an electrical gradient across the membrane.</p> Signup and view all the answers

    What is the overall charge of the intracellular fluid relative to the extracellular fluid?

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

    Why do negatively charged ions remain trapped inside the cell?

    <p>Low permeability of the membrane to negative ions</p> Signup and view all the answers

    What role does the K+ leak channel play in the formation of the resting membrane potential?

    <p>It facilitates the efflux of K+ ions.</p> Signup and view all the answers

    What condition arises due to the selective permeability of the plasma membrane?

    <p>Electrochemical disequilibrium</p> Signup and view all the answers

    What occurs when the concentration gradient and electrical gradient are balanced for K+ ions?

    <p>Net movement of K+ ions is zero.</p> Signup and view all the answers

    Which of the following describes the nature of the plasma membrane in relation to ionic currents?

    <p>It can conduct ionic currents.</p> Signup and view all the answers

    In the context of resting membrane potential, what does the term 'capacitor' refer to?

    <p>The membrane's ability to separate charges.</p> Signup and view all the answers

    What primarily generates the resting membrane potential in living cells?

    <p>The unequal distribution of Na+ and K+ ions</p> Signup and view all the answers

    What happens to the intracellular environment during depolarization?

    <p>It becomes more positively charged</p> Signup and view all the answers

    Which ion is most influential in establishing the resting membrane potential?

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

    What is the role of the Na+-K+ ATPase pump during the resting state of the cell?

    <p>To maintain the concentration gradient of Na+ and K+</p> Signup and view all the answers

    Which of the following ions has a higher concentration in the intracellular fluid compared to the extracellular fluid in a resting cell?

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

    How is the equilibrium potential for an ion determined?

    <p>Using the Nernst equation</p> Signup and view all the answers

    During repolarization, what primarily occurs in the cell?

    <p>Efflux of K+ ions from the cell</p> Signup and view all the answers

    What primarily characterizes the resting membrane potential?

    <p>Dynamic steady state with ionic gradients</p> Signup and view all the answers

    What is the typical value of the resting membrane potential in living cells?

    <p>-70 to -90 mV</p> Signup and view all the answers

    Which statement about the leakage of ions during resting state is correct?

    <p>K+ leaks out of the cell more than Na+</p> Signup and view all the answers

    What is the primary effect of K+ efflux on the intracellular charge?

    <p>It creates a more negative charge inside the cell</p> Signup and view all the answers

    Which component of the resting membrane potential indicates electrical disequilibrium?

    <p>Asymmetric distribution of ions across the membrane</p> Signup and view all the answers

    What is the primary role of the Nernst equation?

    <p>To calculate equilibrium potential for individual ions</p> Signup and view all the answers

    What term is used for the forward motion of signals transmitted down the axon?

    <p>Anterograde neurotransmission</p> Signup and view all the answers

    What is the primary role of dendrites in a neuron?

    <p>To integrate and output electrical signals</p> Signup and view all the answers

    What does a negative equilibrium potential indicate about K+ ions?

    <p>Efflux of K+ ions is favored at rest</p> Signup and view all the answers

    Which structure converts electrical signals into chemical signals in the process of neurotransmission?

    <p>Presynaptic axon terminal</p> Signup and view all the answers

    What is the function of dendritic spines on dendrites?

    <p>To increase contact sites with neighboring neurons</p> Signup and view all the answers

    What type of synapse is primarily associated with excitatory signals?

    <p>Excitatory synapses</p> Signup and view all the answers

    How do neurons utilize neurotransmitters in synaptic communication?

    <p>They release them at the presynaptic axon terminal</p> Signup and view all the answers

    What is retrograde transport in the context of dendritic spines?

    <p>Transporting proteins from the postsynaptic dendrite back to the presynaptic axon terminal</p> Signup and view all the answers

    What occurs during synaptic transmission?

    <p>Chemical signals are converted into electrical signals</p> Signup and view all the answers

    What components are involved in the integration of signals in a neuron?

    <p>Cell body and axon</p> Signup and view all the answers

    What is the role of myelin sheath in neuron function?

    <p>To insulate the axon and speed up signal transmission</p> Signup and view all the answers

    Which of the following best describes graded potentials?

    <p>Localized changes in membrane potential</p> Signup and view all the answers

    What do polyribosomes found in dendritic spines allow for?

    <p>The synthesis of proteins within the spines</p> Signup and view all the answers

    What is the primary function of the synaptic cleft?

    <p>To provide a space for the exchange of chemical signals</p> Signup and view all the answers

    What happens to neurotransmitters once they enter the postsynaptic dendrite?

    <p>They are converted into electrical signals</p> Signup and view all the answers

    Study Notes

    Nervous System - Resting Membrane Potential and Neuron

    • NURS 207 (N01) course covers the Nervous System, focusing on resting membrane potential and neurons.
    • Objectives: Understand the basics of resting membrane potential generation and the anatomy/physiology of a typical neuron.

    Membrane Permeability

    • Phospholipid bilayers in cell membranes are impermeable to charged molecules (e.g., Na+, K+, Cl-, Ca++).
    • These molecules are also insoluble in the hydrophobic membrane core.
    • Large water-soluble molecules (e.g., proteins, nucleic acids, sugars) also require channels to cross the membrane.
    • Small uncharged polar molecules (e.g., CO2, O2, NH3, water, mostly with aquaporins) can cross freely.

    Electrolyte Distribution

    • Interstitial Fluid: Major electrolytes are Na+, Cl-, and HCO3-.
    • Intracellular Fluid: Major electrolytes are K+, HPO42- (phosphate ion), and negatively charged proteins.
    • The uneven distribution of electrolytes creates an electrochemical disequilibrium across the plasma membrane, crucial for generating the resting membrane potential.

    Dominant Ions (Extracellular vs. Intracellular)

    • Extracellular fluid: Primarily Na+ and Cl-.
    • Intracellular fluid: Primarily K+ and negatively charged proteins.

    Electrical Properties of the Cell Membrane

    • Plasma membranes behave as ionic conductors, allowing the flow of ionic currents.
    • Concentration gradients dictate ion flow direction across the membrane.
    • Membranes function as capacitors, holding charges and generating a transmembrane potential. This transmembrane potential (voltage difference) is crucial between intra- and extracellular space.

    Generation of Membrane Potential

    • Equilibrium: When a cell and solution are at electrical and chemical equilibrium the cell membrane acts as an insulator to prevent free movement of ions between cells.
    • Ion Concentration Gradients: The Na+-K+ ATPase creates concentration gradients with 3 Na+ ions pumped out and 2 K+ ions pumped in; this leads to a net intracellular negative charge.
    • Relative Charge Scale: Setting the extracellular fluid to zero (ground) establishes a negative membrane potential (approx. -70 mV) in the cell.

    K+ Leak Channels

    • Plasma membranes have more K+ leak channels than Na+ leak channels.
    • The concentration gradient drives K+ out of the cell.
    • The accompanying negative ions (anions) inside the cell try to follow K+, but are largely trapped by the cell membrane (impermeable to large anions). This further contributes to the negative membrane potential.

    Equilibrium Potential

    • Equilibrium potential is achieved when the opposing forces of the concentration gradient and electrical gradient are balanced.
    • This results in a zero net movement of ions.
    • The resting membrane potential's value is close to the equilibrium potential for K+.

    Resting Membrane Potential

    • All living cells have a resting membrane potential.
    • Chemical and electrical disequilibrium exists between intra- and extracellular fluids in a resting state (not stimulated).
    • The resting potential is the voltage difference across the cell membrane at rest.
    • Maintaining this potential requires ATP and the Na+/K+ pump.
    • At rest, the cell is in a dynamic steady state but not at equilibrium. This state of dynamic steady state involve chemical and electrical disequilibrium.

    Neuron Anatomy and Physiology

    • Structure: Neurons are excitable cells that transmit information via electrical or chemical signals. They have specific parts, including the cell body, dendrites, and axon.

    • Function: Signals flow from dendrites to cell bodies along axons. Neurons receive, process, and transmit information to other neurons or effector cells.

    • Types of Neurons: Neurons are classified into sensory, interneurons, or motor neurons based on their specific functions. This classification is related to their structure.

    • Classification by Structure: Multipolar, bipolar, and unipolar.

    • Classification by Function: Sensory (afferent), interneurons (association), and motor (efferent) neurons.

    Cell Body (Soma)

    • Contains the nucleus and organelles.
    • Occupies a small portion of the neuron's total volume.
    • Proteins produced within the nucleus are transported to other parts of the neuron via cytoskeleton (microtubules).

    Dendrites

    • Thin branches that receive incoming signals from other neurons.
    • Incoming signals are in form of graded potentials.
    • Integration of signals occurs within the cell body.
    • Dendritic spines enable an increased number of possible contact sites between neurons and their neighboring cells.
    • Contain polyribosomes, capable of protein synthesis.

    Axon

    • Long, slender projection that transmits signals away from the cell body.
    • Originates from the axon hillock (trigger zone).
    • Electrical signals are transmitted down the axon and chemical signals at the presynaptic axon terminals (which is a type of region that contain neurotransmitters)
    • Axons have branches (collateral axon terminals) along their length.
    • Presynaptic terminals contains synaptic vesicles filled with neurotransmitters
    • Retrograde transport through Axons is possible, with material moving back to the soma.

    Axonal Transport

    • Transport vesicles and organelles along microtubules within the axon.
    • Requires motor proteins (e.g., kinesin, dynein).
    • Enables bidirectional movement of materials along the axon.

    Additional Information

    • Important Concepts: Resting membrane potentials, graded potentials, action potentials, and the role of ion channels and pumps in maintaining these potentials.
    • Nernst Equation: Used to calculate equilibrium potential for an ion based on concentration gradients and ion charges.
    • Goldman-Hodgkin-Katz (GHK) Equation: Incorporates the permeabilities of multiple ions to estimate the membrane potential. Ions like K+, Na+, and Cl- in an excitable cell are relevant to measure and calculate electrical signals and membrane potentials.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    NURS 207 (N01) Nervous System Resting Membrane Potential & Neuron PDF

    Description

    This quiz on NURS 207 covers the fundamentals of the nervous system, focusing on resting membrane potential and neuron anatomy. Students will explore membrane permeability and electrolyte distribution in cells to understand how they impact neuronal function.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser