Podcast
Questions and Answers
Match the levels of organization in the nervous system:
Match the levels of organization in the nervous system:
Central nervous system (CNS) = Main control center of the body. Peripheral nervous system (PNS) = Connects CNS to limbs and organs. Sensory (afferent) division = Transmits sensory information to the CNS. Motor (efferent) division = Transmits information from CNS to muscles and glands.
Which neuroglial cell type is the most abundant in the CNS?
Which neuroglial cell type is the most abundant in the CNS?
astrocyte
Where in the neuron is an action potential initially generated?
Where in the neuron is an action potential initially generated?
axon hillock
The depolarization phase of an action potential results from the opening of which channels?
The depolarization phase of an action potential results from the opening of which channels?
The repolarization phase of an action potential results from
The repolarization phase of an action potential results from
Hyperpolarization results from
Hyperpolarization results from
What is the magnitude (amplitude) of an action potential?
What is the magnitude (amplitude) of an action potential?
The membranes of neurons at rest are very permeable to _____ but only slightly permeable to _____.
The membranes of neurons at rest are very permeable to _____ but only slightly permeable to _____.
During depolarization, which gradient(s) move(s) Na+ into the cell?
During depolarization, which gradient(s) move(s) Na+ into the cell?
What is the value for the resting membrane potential for most neurons?
What is the value for the resting membrane potential for most neurons?
In which direction is each ion pumped by the Na+-K+ pump?
In which direction is each ion pumped by the Na+-K+ pump?
The concentrations of which two ions are highest outside the cell?
The concentrations of which two ions are highest outside the cell?
Why does injection of a local anesthetic into a finger still cause a loss of sensation of touch?
Why does injection of a local anesthetic into a finger still cause a loss of sensation of touch?
What are the steps in transferring across chemical synapses?
What are the steps in transferring across chemical synapses?
The small space between the sending neuron and the receiving neuron is the _______.
The small space between the sending neuron and the receiving neuron is the _______.
A molecule that carries information across a synaptic cleft is a ____________.
A molecule that carries information across a synaptic cleft is a ____________.
What happens when calcium ions enter the synaptic terminal?
What happens when calcium ions enter the synaptic terminal?
What happens when neurotransmitter molecules bind to receptors in the receiving neuron?
What happens when neurotransmitter molecules bind to receptors in the receiving neuron?
If a signal from a sending neuron makes the receiving neuron more negative inside, what occurs?
If a signal from a sending neuron makes the receiving neuron more negative inside, what occurs?
Which membrane potential occurs because of the influx of Na+ through chemically gated channels in a neuron?
Which membrane potential occurs because of the influx of Na+ through chemically gated channels in a neuron?
Which neurotransmitter(s) is/are the body's natural pain killer?
Which neurotransmitter(s) is/are the body's natural pain killer?
Which neuron circuit pattern is involved in the control of rhythmic activities such as breathing?
Which neuron circuit pattern is involved in the control of rhythmic activities such as breathing?
What component of the reflex arc determines the response to a stimulus?
What component of the reflex arc determines the response to a stimulus?
Which of the following allows us to consciously control our skeletal muscles?
Which of the following allows us to consciously control our skeletal muscles?
Name the 3 nervous system functions.
Name the 3 nervous system functions.
Which of the neuroglial cell types control the flow of cerebrospinal fluid within the CNS?
Which of the neuroglial cell types control the flow of cerebrospinal fluid within the CNS?
Which neuroglial cell types form myelin sheaths within the CNS?
Which neuroglial cell types form myelin sheaths within the CNS?
Which neuroglial cell types are found in the PNS?
Which neuroglial cell types are found in the PNS?
Which glial cells monitor the health of neurons and can transform into macrophages?
Which glial cells monitor the health of neurons and can transform into macrophages?
Which PNS neuroglia form the myelin sheaths around larger nerve fibers in the PNS?
Which PNS neuroglia form the myelin sheaths around larger nerve fibers in the PNS?
Which are bundles of neurofilaments that maintain the shape and integrity of neurons?
Which are bundles of neurofilaments that maintain the shape and integrity of neurons?
A neuron can have only one axon, but the axon may have occasional branches along its length.
A neuron can have only one axon, but the axon may have occasional branches along its length.
Which is the conducting region of the neuron?
Which is the conducting region of the neuron?
What criterion is used to functionally classify neurons?
What criterion is used to functionally classify neurons?
Multipolar is a functional classification of neurons.
Multipolar is a functional classification of neurons.
Most association neurons are confined within the peripheral nervous system (PNS).
Most association neurons are confined within the peripheral nervous system (PNS).
Neurons are also called nerve cells.
Neurons are also called nerve cells.
Unmyelinated fibers conduct impulses faster than myelinated fibers.
Unmyelinated fibers conduct impulses faster than myelinated fibers.
Which neuroglia are the most abundant and versatile of the glial cells?
Which neuroglia are the most abundant and versatile of the glial cells?
Which part of the neuron is responsible for generating a nerve impulse?
Which part of the neuron is responsible for generating a nerve impulse?
Which types of neurons carry impulses away from the central nervous system (CNS)?
Which types of neurons carry impulses away from the central nervous system (CNS)?
Where do most action potentials originate?
Where do most action potentials originate?
What opens first in response to a threshold stimulus?
What opens first in response to a threshold stimulus?
What characterizes depolarization, the first phase of the action potential?
What characterizes depolarization, the first phase of the action potential?
What characterizes repolarization, the second phase of the action potential?
What characterizes repolarization, the second phase of the action potential?
What event triggers the generation of an action potential?
What event triggers the generation of an action potential?
What is the first change to occur in response to a threshold stimulus?
What is the first change to occur in response to a threshold stimulus?
What potential difference is created by the unequal distribution of ions across the plasma membrane?
What potential difference is created by the unequal distribution of ions across the plasma membrane?
Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel?
Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel?
On average, what does the resting membrane potential of -70 mV indicate?
On average, what does the resting membrane potential of -70 mV indicate?
Why is the plasma membrane more permeable to K+ than to Na+?
Why is the plasma membrane more permeable to K+ than to Na+?
What two factors influence the resting membrane potential?
What two factors influence the resting membrane potential?
What prevents the Na+ and K+ gradients from dissipating?
What prevents the Na+ and K+ gradients from dissipating?
Arrange these parts in order, from left to right, of a successful direct depolarization path within one neuron: axon, axon hillock, cell body, dendrite, presynaptic terminal.
Arrange these parts in order, from left to right, of a successful direct depolarization path within one neuron: axon, axon hillock, cell body, dendrite, presynaptic terminal.
Which best characterizes depolarization?
Which best characterizes depolarization?
What is the primary stimulus for vesicles to move towards the cell membrane and release neurotransmitter?
What is the primary stimulus for vesicles to move towards the cell membrane and release neurotransmitter?
Which statement best describes exocytosis?
Which statement best describes exocytosis?
What conditions will increase the diffusion of molecules, such as neurotransmitters?
What conditions will increase the diffusion of molecules, such as neurotransmitters?
What must happen for a postsynaptic dendrite to set up a graded potential after neurotransmitter release?
What must happen for a postsynaptic dendrite to set up a graded potential after neurotransmitter release?
Sequence at the chemical synapse in correct order:
Sequence at the chemical synapse in correct order:
Which best represents synaptic transmission?
Which best represents synaptic transmission?
What effect does blocking neurotransmitter receptors on the postsynaptic membrane have?
What effect does blocking neurotransmitter receptors on the postsynaptic membrane have?
What is an example of a presynaptic cell?
What is an example of a presynaptic cell?
Which component has a role in the postsynaptic cell during synaptic activity?
Which component has a role in the postsynaptic cell during synaptic activity?
What is the role of calcium in synaptic activity?
What is the role of calcium in synaptic activity?
What is the role of neurotransmitter at a chemical synapse?
What is the role of neurotransmitter at a chemical synapse?
Neurotransmitter is released from presynaptic neurons through what mechanism?
Neurotransmitter is released from presynaptic neurons through what mechanism?
What type of channel on the postsynaptic membrane binds neurotransmitter?
What type of channel on the postsynaptic membrane binds neurotransmitter?
In addition to diffusion, what are two mechanisms that terminate neurotransmitter activity?
In addition to diffusion, what are two mechanisms that terminate neurotransmitter activity?
Arrange the events during synaptic activity in the correct order:
Arrange the events during synaptic activity in the correct order:
In a synapse, neurotransmitters are stored in vesicles located in the __________.
In a synapse, neurotransmitters are stored in vesicles located in the __________.
An action potential releases neurotransmitter from a neuron by opening which of the following channels?
An action potential releases neurotransmitter from a neuron by opening which of the following channels?
Binding of a neurotransmitter to its receptors opens __________ channels on the __________ membrane.
Binding of a neurotransmitter to its receptors opens __________ channels on the __________ membrane.
Binding of the neurotransmitter to its receptor causes the membrane to __________.
Binding of the neurotransmitter to its receptor causes the membrane to __________.
Which neurotransmitter is broken down by an enzyme before being returned?
Which neurotransmitter is broken down by an enzyme before being returned?
Study Notes
Levels of Organization in the Nervous System
- Central nervous system (CNS) includes the brain and spinal cord.
- Peripheral nervous system (PNS) divided into sensory (afferent) and motor (efferent) divisions.
- Motor division further splits into somatic and autonomic nervous systems (ANS) with sympathetic and parasympathetic divisions.
Neuroglial Cells
- Astrocytes are the most abundant neuroglial cells in the CNS, providing support and nutrition.
- Ependymal cells regulate cerebrospinal fluid flow within the CNS.
- Oligodendrocytes form myelin sheaths in the CNS, while Schwann cells do so in the PNS.
- Microglia act as immune cells, transforming into macrophages to protect neurons.
Action Potentials
- Action potentials are initially generated at the axon hillock.
- The depolarization phase occurs due to the opening of voltage-gated Na+ channels.
- Repolarization follows through the opening of voltage-gated K+ channels.
- Hyperpolarization takes place from the slow closing of voltage-gated K+ channels.
- The maximum amplitude of an action potential is approximately 100 mV.
- The resting membrane potential for most neurons is -70 mV, with higher permeability to K+ compared to Na+.
Ion Flow and Membrane Potential
- During depolarization, both electrical and chemical gradients drive Na+ into the cell.
- Sodium and chloride ions have higher concentrations outside the cell.
- The Na+-K+ pump actively maintains ion gradients by transporting Na+ out and K+ into the cell.
Synaptic Transmission
- Local anesthetics block voltage-gated Na+ channels, preventing action potential generation despite mechanical stimulation.
- Chemical synapse transmission involves the release of neurotransmitters from presynaptic terminals into the synaptic cleft.
- Action potential arrival opens calcium channels, allowing Ca2+ influx and leading to neurotransmitter release via exocytosis.
- Graded potentials in the postsynaptic neuron occur when neurotransmitters bind to receptors, opening ion channels.
Reflex Arcs and Neural Circuits
- Reflex arcs consist of sensory input, integration centers, and motor output.
- The integration center determines responses to stimuli.
- Reverberating circuits support rhythmic activities, such as breathing.
Neurotransmitters and Receptors
- Endorphins serve as natural painkillers.
- Neurotransmitter activity is terminated through diffusion, reuptake, or degradation.
- The binding of neurotransmitters to receptors opens chemically gated channels on the postsynaptic membrane.
Neuron Structure and Function
- Neurons contain structures like axons (the conducting region), cell bodies, and dendrites.
- Neurons can have multiple branches from a single axon but only one axon overall.
- Neurons are classified functionally based on impulse direction relative to the CNS, categorized as sensory, motor, and association neurons.
Mechanisms of Action Potential Generation
- An action potential is triggered when the membrane potential reaches a threshold of -55 mV from -70 mV.
- Depolarization involves a rapid shift from a negative to a positive membrane potential, peaking at +30 mV, followed by repolarization.
- Leak channels are responsible for the diffusion of Na+ and K+ across membranes, helping establish resting membrane potential.
Importance of Calcium and Vesicle Function
- Calcium's influx into the axon terminal is crucial for vesicle fusion and neurotransmitter release.
- Calcium channels open in response to action potentials, initiating synaptic transmission processes.
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Description
Test your knowledge on the nervous system and its organization with this Chapter 11 quiz. Covering topics from the central and peripheral nervous systems to neuroglial cells, this quiz will help reinforce your understanding of nervous tissue. Challenge yourself to master the key concepts!
