Podcast
Questions and Answers
What does the Nernst Equation calculate?
What does the Nernst Equation calculate?
- Resting membrane potential of a neuron
- Equilibrium potential for one ion (correct)
- Membrane potential for multiple ions
- Total ion concentration inside a cell
Which variable represents the concentration of an ion outside the cell in the Nernst Equation?
Which variable represents the concentration of an ion outside the cell in the Nernst Equation?
- (I)i
- Z
- (I)o (correct)
- Ei
What is hyperpolarization defined as?
What is hyperpolarization defined as?
- A change to a more negative value (correct)
- A change to a less negative value
- Returning to resting membrane potential
- A change in sodium ion concentrations
What does repolarization indicate?
What does repolarization indicate?
In the Goldman-Hodgkin-Katz (GHK) Equation, what ions are primarily considered for calculating membrane potential?
In the Goldman-Hodgkin-Katz (GHK) Equation, what ions are primarily considered for calculating membrane potential?
What initiates the changes in membrane potential?
What initiates the changes in membrane potential?
Which term describes a change in membrane potential to a less negative or positive value?
Which term describes a change in membrane potential to a less negative or positive value?
What does the valence of the ion (Z) indicate in the Nernst Equation?
What does the valence of the ion (Z) indicate in the Nernst Equation?
What primarily determines the resting membrane potential of a neuron?
What primarily determines the resting membrane potential of a neuron?
Which channel type is responsible for maintaining the resting membrane potential?
Which channel type is responsible for maintaining the resting membrane potential?
Which division of the nervous system is responsible for voluntary control of skeletal muscles?
Which division of the nervous system is responsible for voluntary control of skeletal muscles?
What characterizes ligand-gated ion channels?
What characterizes ligand-gated ion channels?
What is primarily responsible for the transmission of neural impulses?
What is primarily responsible for the transmission of neural impulses?
Which component of the central nervous system includes both the brain and spinal cord?
Which component of the central nervous system includes both the brain and spinal cord?
Where are voltage-gated Na+ channels mostly found in a neuron?
Where are voltage-gated Na+ channels mostly found in a neuron?
What is the primary function of glial cells in the nervous system?
What is the primary function of glial cells in the nervous system?
Which of the following ions contributes to the inside of the cell being negatively charged at rest?
Which of the following ions contributes to the inside of the cell being negatively charged at rest?
What happens to the permeability of the plasma membrane when ion channels open?
What happens to the permeability of the plasma membrane when ion channels open?
Which of the following is NOT a part of the peripheral nervous system?
Which of the following is NOT a part of the peripheral nervous system?
The concentration gradient of K+ across the plasma membrane is primarily established by which mechanism?
The concentration gradient of K+ across the plasma membrane is primarily established by which mechanism?
Which subdivision of the peripheral nervous system carries sensory information to the central nervous system?
Which subdivision of the peripheral nervous system carries sensory information to the central nervous system?
What primarily triggers the release of neurotransmitters in neurons?
What primarily triggers the release of neurotransmitters in neurons?
What structures lack centrioles, indicating their maturity in neuron development?
What structures lack centrioles, indicating their maturity in neuron development?
Which part of a neuron is primarily involved in receiving information?
Which part of a neuron is primarily involved in receiving information?
What happens during the depolarization phase of an action potential?
What happens during the depolarization phase of an action potential?
What occurs during repolarization of an action potential?
What occurs during repolarization of an action potential?
What is the primary factor that influences the threshold for action potential initiation?
What is the primary factor that influences the threshold for action potential initiation?
What characterizes the all-or-none principle of action potentials?
What characterizes the all-or-none principle of action potentials?
Which ion's movement primarily contributes to after-hyperpolarization?
Which ion's movement primarily contributes to after-hyperpolarization?
How does increased permeability to Na+ affect the membrane potential?
How does increased permeability to Na+ affect the membrane potential?
What is the role of voltage-gated K+ channels during an action potential?
What is the role of voltage-gated K+ channels during an action potential?
What occurs at the peak of the action potential?
What occurs at the peak of the action potential?
Which factor primarily determines the conduction velocities of nerve fibers?
Which factor primarily determines the conduction velocities of nerve fibers?
What triggers the release of neurotransmitters in the presynaptic neuron?
What triggers the release of neurotransmitters in the presynaptic neuron?
What is the relationship between myelination and conduction velocity?
What is the relationship between myelination and conduction velocity?
Which neurotoxin blocks voltage-gated Na+ channels?
Which neurotoxin blocks voltage-gated Na+ channels?
What occurs after the neurotransmitter binds to receptors on the postsynaptic membrane?
What occurs after the neurotransmitter binds to receptors on the postsynaptic membrane?
What characteristic of nerve fibers most significantly influences their conduction speed?
What characteristic of nerve fibers most significantly influences their conduction speed?
Which of the following describes a fate of the neurotransmitter after its release?
Which of the following describes a fate of the neurotransmitter after its release?
What type of neurotoxin is primarily found in some marine dinoflagellates?
What type of neurotoxin is primarily found in some marine dinoflagellates?
What role do enzymes play in neurotransmitter activity?
What role do enzymes play in neurotransmitter activity?
What initiates the opening of calcium channels in the presynaptic neuron?
What initiates the opening of calcium channels in the presynaptic neuron?
What is a common feature of neurotoxins affecting the nervous system?
What is a common feature of neurotoxins affecting the nervous system?
Which of the following statements about conduction velocities is true?
Which of the following statements about conduction velocities is true?
What concentration level makes Tetrodotoxin (TTX) toxic?
What concentration level makes Tetrodotoxin (TTX) toxic?
Flashcards
Central Nervous System (CNS)
Central Nervous System (CNS)
The brain and spinal cord, responsible for processing and transmitting information throughout the body.
Peripheral Nervous System (PNS)
Peripheral Nervous System (PNS)
The network of nerves that connect the CNS to the rest of the body, responsible for transmitting signals to and from the CNS.
Nerves
Nerves
Bundles of nerve fibers that transmit signals throughout the body.
Ganglia
Ganglia
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Afferent/Sensory Division
Afferent/Sensory Division
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Efferent/Motor Division
Efferent/Motor Division
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Somatic Motor Nervous System
Somatic Motor Nervous System
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Autonomic Nervous System (ANS)
Autonomic Nervous System (ANS)
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Resting Membrane Potential
Resting Membrane Potential
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Ion Channels
Ion Channels
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Membrane Permeability
Membrane Permeability
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Ligand-Gated Channel
Ligand-Gated Channel
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Voltage-Gated Channel
Voltage-Gated Channel
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Concentration Gradient
Concentration Gradient
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Electrical Force
Electrical Force
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Chemical Force
Chemical Force
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Depolarization
Depolarization
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Repolarization
Repolarization
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Afterhyperpolarization
Afterhyperpolarization
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Membrane permeability changes
Membrane permeability changes
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Increased permeability to Na+
Increased permeability to Na+
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Decreased permeability to Na+
Decreased permeability to Na+
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Increased permeability to K+
Increased permeability to K+
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All-or-none principle
All-or-none principle
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Nernst Equation
Nernst Equation
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Valence of an Ion
Valence of an Ion
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GHK Equation
GHK Equation
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Electrical Signal
Electrical Signal
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Gated-Ion Channels
Gated-Ion Channels
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Hyperpolarization
Hyperpolarization
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Action potential
Action potential
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Ca2+ influx at the synapse
Ca2+ influx at the synapse
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Neurotransmitter release (exocytosis)
Neurotransmitter release (exocytosis)
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Neurotransmitter binding and response
Neurotransmitter binding and response
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Neurotransmitter removal from the synapse
Neurotransmitter removal from the synapse
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Nerve Conduction Velocity
Nerve Conduction Velocity
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What determines nerve conduction velocity?
What determines nerve conduction velocity?
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How do diameter and myelination affect nerve conduction velocity?
How do diameter and myelination affect nerve conduction velocity?
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What are neurotoxins?
What are neurotoxins?
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What are Tetrodotoxin (TTX) and Saxitoxin (STX) and how do they affect nerve function?
What are Tetrodotoxin (TTX) and Saxitoxin (STX) and how do they affect nerve function?
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Why are Tetrodotoxin (TTX) and Saxitoxin (STX) dangerous?
Why are Tetrodotoxin (TTX) and Saxitoxin (STX) dangerous?
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How do TTX and STX block voltage-gated sodium channels?
How do TTX and STX block voltage-gated sodium channels?
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What are the effects of TTX and STX?
What are the effects of TTX and STX?
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Study Notes
Nervous System Physiology - Neurophysiology
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Nervous System Divisions: Central Nervous System (CNS) encompasses the brain and spinal cord. Peripheral Nervous System (PNS) includes sensory (afferent) and motor (efferent) components. Somatic nervous system controls skeletal muscles; autonomic nervous system regulates involuntary functions with sympathetic (fight-or-flight) and parasympathetic (rest-and-digest) branches.
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Neurons: The structural and functional units; glial cells support them. Neuron types are diverse based on function and structure.
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Glial Cells: Outnumber neurons (70-90% in CNS), support neurons structurally and metabolically and play roles in the blood-brain barrier, and forming myelin sheaths.
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Resting Membrane Potential: The electrical potential difference across a neuron's cell membrane at rest, typically -70mV, largely due to ion concentration gradients.
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Action Potential: Rapid changes in membrane potential, initiated by stimulation, and propagated by ion movement creating an electrical signal. Ion channels are key.
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Nerve Fiber Types: Myelinated and unmyelinated fibers differ in conduction speed. Myelinated fibers are faster allowing saltatory conduction.
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Synapse: The junction between two neurons or a neuron and an effector (muscle or gland), mediating communication. Transmission is via chemical signals- neurotransmitters at chemical synapses.
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Synaptic Transmission: Neurotransmitters are released from presynaptic neuron, bind to receptors on postsynaptic neuron, initiating changes in the postsynaptic cell.
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Types of Synapses: Electrical synapses transmit signals quickly; chemical synapses use neurotransmitters for transmission. Specialized chemical synapses are lonotropic and metabotropic receptors.
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Neurotransmitters: Various kinds (e.g., acetylcholine, glutamate, GABA) are involved, triggering specific responses in the receiving cells based on the receptors to which they bind.
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Excitatory Postsynaptic Potentials (EPSPs) and Inhibitory Postsynaptic Potentials (IPSPs): Graded potentials; EPSPs depolarize membrane, IPSPs hyperpolarize, influencing whether an action potential is generated in the receiving neuron.
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Neurotransmitters and Synaptic Transmission: Neurotransmitter binding elicits postsynaptic potential (PSP), excitatory (EPSP) or inhibitory (IPSP), changing membrane potential, potentially leading to action potentials.
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Neural Integration: Processes by which multiple synaptic inputs are combined to produce a response in a neuron. Divergent and convergent pathways in nervous system circuits influence response and behavior, and summation of signals.
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Action Potential Propagation: Depolarization in myelinated axons is faster via saltatory conduction happening at Nodes of Ranvier, while unmyelinated axons have continuous conduction.
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Refractory Period: A period following an action potential when the neuron is less responsive or cannot generate another action potential. Periods are absolute and relative.
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Neurotoxins: Chemicals can interfere with normal nervous system function by affecting ion channels.
Neuronal Structures and Functions, Classification
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Neuron structure: Cell body (soma) with nucleus, dendrites (receiving signals), axons (transmitting signals), and axon terminals (sending signals to other cells).
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Neuron classification (structural): Bipolar (one axon and dendrite);
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Pseudo-unipolar (single extension that branches into two);
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multipolar (multiple dendrites and one axon).
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Neuron classification (functional): Sensory (afferent), motor (efferent), interneurons.
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Glial Cells: Support, protect, and nourish neurons. Types include astrocytes, oligodendrocytes, microglia, and ependymal cells (with different functions).
Neural Integration
- Divergent Pathways: A single neuron synapses on multiple downstream neurons, amplifying a signal.
- Convergent Pathways: Multiple neurons synapse onto a single downstream neuron.
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Description
Test your knowledge on the concepts of membrane potential, ion channels, and the Nernst and GHK equations in this neuroscience quiz. Understand key terms like hyperpolarization and repolarization, and their importance in neural activities.
