Chapter 12 Nervous System
Which term refers to the passage of proteins, organelles and other materials along an axon? Synaptic signaling Active transport Axonal transport Secretion
Axonal Transport
Choose the name of the thin layer of fibrous connective tissue found around myelin in nerve fibers of the peripheral nervous system. Endoneurium Axolemma Varicosity Axoplasm
Endoneurium
List the fundamental physiological properties of neurons. Elasticity, conductivity, contractility Excitability, irritability, highly mitotic Conductivity, contractility, excitability Excitability, conductivity, secretion
Excitability, conductivity, secretion
Which are names for the cell body of a neuron? Neurosoma Inclusion Astrocyte Ganglion Soma
Neurosoma, Soma
In the CNS, myelin is produced by glial cells called ________________.
Ogliodendrocytes
Which ion has the greatest influence on the resting membrane potential of most neurons? Potassium Calcium Chloride Sodium
Potassium
Which ion has the greatest influence on the resting membrane potential of most neurons? Sodium Calcium Potassium Chloride
Potassium
Which neuroglial cell is found in the peripheral nervous system? Ependymal cell Astrocyte Oligodendrocytes Satellite cell
Satellite cell
Which type of glial cell produces the myelin sheath in the PNS? Satellite cell Oligodendrocyte Ependymal cell Schwann cell
Schwann Cell
Which type of glial cell produces the myelin sheath in the PNS? Schwann cell Oligodendrocyte Ependymal cell Satellite cell
Schwann Cell
In the PNS; form neurilemma around all PNS fibers and myelin around most of them; aid in regeneration of damaged nerve fibers.
Schwann Cells
Which type of glial cell aids in regeneration of damaged peripheral nerve fibers by forming a regeneration tube to help reestablish the former connection? Satellite cells Oligodendrocytes Ependymal cells Schwann cells
Schwann Cells
Choose the characteristics of neuroglia. Their main properties are excitability and conductivity. They bind neurons together and provide a supportive scaffold. They are less numerous than neurons. They protect the neurons and help them function.
They bind neurons together and provide a supportive scaffold. They protect the neurons and help them function.
Choose the characteristics of neuroglia. They are less numerous than neurons. Their main properties are excitability and conductivity. They bind neurons together and provide a supportive scaffold. They protect the neurons and help them function.
They bind neurons together and provide a supportive scaffold. They protect the neurons and help them function.
True or false: Unmyelinated nerve fibers (axons) in the PNS are enveloped in Schwann cells. True False
True
Which type of neuron has one single process that branches like a T into a peripheral fiber and a central fiber? Bipolar Anaxonic Multipolar Unipolar
Unipolar
Which lists the structural categories of neurons? Neurons, glia, satellite cells Afferent, association, and efferent Sensory, motor, and interneurons Unipolar, bipolar, anaxonic, and multipolar
Unipolar, bipolar, anaxonic, and multipolar
Together, the sympathetic and parasympathetic nervous systems make up the entirety of which division of the nervous system? Somatic motor Somatic sensory Visceral motor Motor
Visceral Motor
Another term for sensory division is ______ division.
afferent
A neuron with one axon and one dendrite is structurally classified as a ______________ neuron.
bipolar
In a chemical synapse, synaptic vesicles full of neurotransmitter are docked at release sites on the membrane of the presynaptic neuron, while neurotransmitter receptors are found on the membrane of the ______________ neuron.
postsynaptic
The refractory period in which it is possible to trigger a new action potential, but only with an unusually strong stimulus is the ______ refractory period. relative absolute
relative
Which term refers to the voltage difference (electrical potential) across the plasma membrane of a neuron when it is at rest and not engaged in electrical signaling? Resting membrane potential Action potential Postsynaptic potential Local potential
resting membrane potential
What are the three general classes of neurons that correspond to the three major aspects of nervous system function? Check all that apply. Check All That Apply -Motor neurons that send signals predominantly to muscle and gland cells -Schwann cells that envelop nerve fibers of the PNS -Interneurons that lie between, and interconnect the incoming sensory pathways and the outgoing motor pathways of the CNS -Sensory neurons that are specialized to detect stimuli such as light, heat, pressure, and chemicals and transmit information about them to the CNS -Ependymal cells that produce cerebral spinal fluid
- Motor neurons that send signals predominantly to muscle and gland cells - interneurons that lie between, and interconnect the incoming sensory pathways and the outgoing motor pathways of the CNS - Sensory neurons that are specialized to detect stimuli such as light, heat, pressure, and chemicals, and transmit information about them to the CNS
Indicate the correct order of events that occur during a single action potential: -local potential increases membrane potential -hyperpolarization -threshold is reached -depolarized spike -repolarization
1. Local potential increases membrane potential 2. Threshold is reached 3. Depolarization spike 4. Repolarization 5. Hyperpolarization
Which best describes an electrical potential? A form of potential energy that can produce current The opposition to the flow of electrical current across a membrane The movement of charged particles like ions A positively or negatively charged atom or molecule
A form of potential energy that can produce current
Which best describes signal conduction in unmyelinated axons? The entire axon depolarizes at the same time. The signal is transmitted from one node of Ranvier to the next through saltatory conduction. A local potential is passively conducted down the entire length of the axon. A wave of depolarization opens more voltage-gated channels immediately distal to the action potential.
A wave of depolarization opens more voltage-gated channels immediately distal to the action potential
Which best describes signal conduction in unmyelinated axons? The entire axon depolarizes at the same time. The signal is transmitted from one node of Ranvier to the next through saltatory conduction. A local potential is passively conducted down the entire length of the axon. A wave of depolarization opens more voltage-gated channels immediately distal to the action potential.
A wave of depolarization opens more voltage-gated channels immediately distal to the action potential.
Which best describes signal conduction in unmyelinated axons? The signal is transmitted from one node of Ranvier to the next through saltatory conduction. A local potential is passively conducted down the entire length of the axon. The entire axon depolarizes at the same time. A wave of depolarization opens more voltage-gated channels immediately distal to the action potential.
A wave of depolarization opens more voltage-gated channels immediately distal to the action potential.
This picture illustrates signal conduction along unmyelinated fibers. Indicate which of the following statements are true about this type of conduction. A zone of depolarization excites voltage-gated channels immediately distal to the action potential. Unmyelinated fibers have voltage-gated channels along their entire length. The red band in the diagram represents the relative refractory period. The signal conduction in unmyelinated fibers is saltatory.
A zone of depolarization excites voltage-gated channels immediately distal to the action potential. Unmyelinated fibers have voltage-gated channels along their entire length.
Neurons that have one axon and one dendrite, such as olfactory cells, certain neurons of the retina, and sensory neurons of the inner ear, are classified as which of the following? Bipolar Unipolar Multipolar
Bipolar
If a drug was developed that interfered with the proper functioning of the microtubules found within the axons of neurons, how would you expect this to impact axonal transport processes? Retrograde transport would cease. The production of substances within the cell body would cease. Anterograde transport would cease. Both anterograde and retrograde transport processes would cease.
Both anterograde and retrograde transport processes would cease
At a GABA-ergic synapse, the postsynaptic receptor for the GABA neurotransmitter is which type of channel? Calcium Potassium Sodium Chloride
Chloride
The enzyme choline acetyltransferase catalyzes the reaction between acetyl-CoA and choline resulting in the formation of the neurotransmitter acetylcholine. This enzyme is produced within the cell body of neurons, but the synthesis of acetylcholine occurs within the axon terminals. Which statement best describes the axonal transport mechanism associated with this process? Acetylcholine is transported in the retrograde direction. Acetylcholine is transported in the anterograde direction. Choline acetyltransferase is transported in the anterograde direction. Choline acetyltransferase is transported in the retrograde direction.
Choline acetyltransferase is transported in the anterograde direction
Which term refers to a synapse that releases acetylcholine from the presynaptic axon terminal? Adrenergic Serotonergic Cholinergic Electrical
Cholinergic
Which term refers to the flow of charged particles from one point to another? Conductance Current Electrical potential Resistance
Current
Which term refers to the upward change in membrane potential during an action potential? Repolarization Depolarization Polarization Hyperpolarization
Depolarization
Which would cause postsynaptic stimulation to end? Diffusion of neurotransmitter from the synaptic cleft into extracellular fluid Addition of receptors onto presynaptic membrane Cessation of signals in the presynaptic nerve fiber Enzymatic degradation of neurotransmitter in the synaptic cleft Reuptake of neurotransmitter into the presynaptic knob
Diffusion of neurotransmitter from the synaptic cleft into extracellular fluid Cessation of signals in the presynaptic nerve fiber Enzymatic degradation of neurotransmitter in the synaptic cleft Reuptake of neurotransmitter into the presynaptic knob
Which neurotransmitters are classified as neuropeptides? Acetylcholine GABA Endorphins Cholecystokinin Serotonin
Endorphins Cholecystokinin
Select all that apply Which would cause postsynaptic stimulation to end? Enzymatic degradation of neurotransmitter in the synaptic cleft Addition of receptors onto presynaptic membrane Reuptake of neurotransmitter into the presynaptic knob Cessation of signals in the presynaptic nerve fiber Diffusion of neurotransmitter from the synaptic cleft into extracellular fluid
Enzymatic degradation of neurotransmitter in the synaptic cleft Reuptake of neurotransmitter into the presynaptic knob Cessation of signals in the presynaptic nerve fiber Diffusion of neurotransmitter from the synaptic cleft into extracellular fluid
In the CNS; line cavities of the brain and spinal cord; secrete and circulate CSF
Ependymal Cells
Acetylcholine is actively transported from the presynaptic membrane to the postsynaptic membrane. True or False
False
True or false: All neurotransmitters have an excitatory effect. True False
False
True or false: Damaged nerve fibers in the CNS regenerate very fast whereas damaged nerve fibers in the PNS never regenerate. True False
False
True or false: Electrical synapses are able to integrate information and make decisions more rapidly than chemical signals. True False
False
Which of the following are effectors? -Stimuli -Sense Organs -Glands -Reflexes -Receptors
Glands
______ cells protect the neurons and help them function.
Glial
______ cells protect the neurons and help them function. Afferent Multipolar Glial Efferent
Glial
Which neurotransmitters are classified as amino acids? Glutamate Serotonin Epinephrine Acetylcholine GABA Cholecystokinin
Glutamate GABA
Inhibitory postsynaptic potentials (IPSPs) are associated with which of the following? -Depolarization of the cell membrane -Repolarization of the cell membrane -Hyperpolarization of the cell membrane -No change in the cell membrane potential -No change of the threshold
Hyperpolarization of the cell membrane potential
About 90% of the neurons in the nervous system are ________________ neurons -sensory -efferent -afferent -motor -inter neurons/ association
Inter neurons/ association
Which correctly describe axonal transport? It involves transport of proteins within the axon (i.e. synaptic knob enzymes or proteins that maintain the axolemma). It is bidirectional (retrograde and anterograde transport). It is a type of transport that occurs only in anaxonic neurons.
It involves transport of proteins within the axon (i.e. synaptic knob enzymes or proteins that maintain the axolemma). It is bidirectional (retrograde and anterograde transport).
Choose the correct statement about myelin. Multiple Choice -It is best not to give children under two years of age a low-fat diet because myelin formation requires lipids. -It is formed by oligodendrocytes in the peripheral nervous system and Schwann cells in the central nervous system. -It is about 80% protein and 20% lipid. -The myelin sheath is segmented, and the gaps between the segments are called internodes. -Multiple sclerosis results from the abnormal accumulation of a glycolipid called GM2 (ganglioside) in the myelin sheath.
It is best not to give children under two years of age a low-fat diet because myelin formation requires lipids.
Which correctly describe axonal transport? It is a type of transport that occurs only in anaxonic neurons. It is bidirectional (retrograde and anterograde transport). It involves transport of proteins within the axon (i.e. synaptic knob enzymes or proteins that maintain the axolemma).
It is bidirectional (retrograde and anterograde transport) It involves the transport of proteins within the axon (i.e. synaptic knob enzymes or proteins that maintain the axolemma)
Which correctly describe axonal transport? It is a type of transport that occurs only in anaxonic neurons. It is bidirectional (retrograde and anterograde transport). It involves transport of proteins within the axon (i.e. synaptic knob enzymes or proteins that maintain the axolemma).
It is bidirectional (retrograde and anterograde transport). It involves transport of proteins within the axon (i.e. synaptic knob enzymes or proteins that maintain the axolemma).
Which of the following contributes to the development of the resting membrane potential in neurons? K+ is more concentrated in the ECF than in the ICF. Na+ is more concentrated in the ICF than in the ECF. K+ is more concentrated in the ICF than in the ECF. Na+ and K+ have equal concentrations on both sides of the membrane.
K+ is more concentrated in the ICF than in the ECF
Which of the following contributes to the development of the resting membrane potential in neurons? K+ is more concentrated in the ECF than in the ICF. K+ is more concentrated in the ICF than in the ECF. Na+ is more concentrated in the ICF than in the ECF. Na+ and K+ have equal concentrations on both sides of the membrane.
K+ is more concentrated in the ICF than the ECF
Acetylcholine has which effect on the postsynaptic neuron? Multiple Choice Ligand-gated calcium ion channels open, and calcium diffuses in. Ligand-gated sodium ion channels open, and sodium diffuses in. Terminal vessels migrate to the plasma membrane. Voltage-gated calcium ion channels open, and calcium diffuses in. Voltage-gated sodium ion channels open, and sodium diffuses in.
Ligand-gated sodium ion channels open, and sodium diffuses in
The myelin sheath is composed mostly of which of the following? Lipids Proteins Glycoproteins Carbohydrates
Lipids
In the CNS; phagocytize microorganisms, foreign matter, and dead nervous tissue
Microglia
Which type of glial cells in the central nervous system fight microorganisms and destroy foreign matter and dead nervous tissue? Astrocytes Ependymal cells Satellite cells Microglia
Microglia
Select the four categories of neurotransmitters based on chemical composition. Monoamines Amino acids Neuropeptides Acetylcholine Glycoproteins Sterols
Monoamines Amino acids Neuropeptides Acetylcholine
Why does depolarization occur? Multiple Choice More K+ diffuse into the cell than Na+ diffuse out of it. More K+ diffuse out of the cell than Na+ diffuse into it. More Na+ diffuse into the cell than K+ diffuse out of it. More Na+ diffuse out of the cell than K+ diffuse into it. Both Na+ and K+ diffuse into the cell.
More Na+ diffuse into the cell than K+ diffuse out of it
What are the three general classes of neurons that correspond to the three major aspects of nervous system function? Check all that apply. -Motor neurons that send signals predominantly to muscle and gland cells -Schwann cells that envelop nerve fibers of the PNS -Interneurons that lie between, and interconnect the incoming sensory pathways and the outgoing motor pathways of the CNS -Sensory neurons that are specialized to detect stimuli such as light, heat, pressure, and chemicals and transmit information about them to the CNS =Ependymal cells that produce cerebral spinal fluid
Motor neurons that send signals predominantly to muscle and gland cells Interneurons that lie between, and interconnect the incoming sensory pathways and the outgoing motor pathways of the CNS Sensory neurons that are specialized to detect stimuli such as light heat pressure and chemicals and transmit information about them to the CNS
During depolarization, which of the following statements about voltage-gated ion channels is true? Multiple Choice K+ gates open before Na+ gates. Na+ gates open before K+ gates. Na+ and K+ gates open at the same time. K+ gates open while Na+ gates remain closed.
Na+ gates open before K+ gates
Cholecystokinin and substance P are examples of which type of neurotransmitter? Monoamines Amino acids Neuropeptides Biogenic amines
Neuropeptides
Stimulation of the postsynaptic neuron will end when nerve signals stop arriving at the presynaptic axon terminal or when which of the following occurs? -All postsynaptic receptors have neurotransmitter bound to them. -Receptors on postsynaptic membrane are removed. -Neurotransmitter is removed from postsynaptic receptors.
Neurotransmitter is removed from postsynaptic receptors
Which term refers to the gaps between segments of myelin along an axon? Nodes of Ranvier Synapses Internodes Initial segments
Nodes of Ranvier
Which are properties of action potentials? Nondecremental (signal maintains amplitude) Self-propagating Graded (amplitude proportional to stimulus strength) All or none
Nondecremental (signal maintains amplitude) Self-propagating All or none
Which types of glial cells are found in the central nervous system? Oligodendrocytes Astrocytes Ependymal cells Microglia Satellite cells Schwann cells
Oligodendrocytes Astrocytes Ependymal Cells Microglia
Which types of glial cells are found in the central nervous system? Check all that apply. Oligodendrocytes Ependymal cells Microglia Astrocytes Schwann cells Satellite cells
Oligodendrocytes Ependymal Cells Microglia Astrocytes
GABA has an inhibitory effect on postsynaptic neurons because it does which of the following? Closes potassium channels Opens sodium channels Opens chloride channels Closes calcium channels
Opens chloride channels
An electrical potential is a form of what type of energy? Kinetic energy Thermal energy Potential energy Chemical energy
Potential energy
Which factors influence the speed of nerve signal conduction? Size of soma Presence of myelin Type of neuron (multipolar vs. unipolar) Diameter of axon
Presence of myelin Diameter of axon
_______________ the time between signals sent from the same presynaptic terminal increases the strength of the graded potential. This is an example of ________________ summation. Reducing; spatial Increasing; temporal Increasing; spatial Reducing; temporal
Reducing; temporal
Which neurotransmitters are classified as monoamines? Serotonin Acetylcholine Glutamate Epinephrine GABA Cholecystokinin
Serotonin Epinephrine
Why is sodium more concentrated in the ECF than in the ICF of most neurons? There are no ion channels in the neuronal membrane. The neuronal membrane is more permeable to potassium than it is to sodium at rest. Sodium is actively pumped out of the cell by transporter proteins. Potassium and sodium are both cations.
Sodium is actively pumped out of the cell by transporter proteins
The sensory and motor divisions of the peripheral nervous system are further split into which two subdivisions? Autonomic and voluntary Spinal cord and brain Somatic and visceral Proximal and distal
Somatic and Visceral
Which division inhibits digestion? Parasympathetic Sympathetic
Sympathetic
Which of the following statements about the resting membrane potential is true? Multiple Choice The exterior of the cell has a net negative charge, and the interior has a net positive charge. The exterior of the cell has a net negative charge, and the interior is neutral. The exterior of the cell has a net positive charge, and the interior has a net negative charge. The exterior of the cell has a net positive charge, and the interior is neutral. The exterior of the cell is neutral, and the interior has a net negative charge.
The exterior of the cell has a net positive charge, and the interior has a net negative charge
A negative membrane potential indicates which of the following? Both sides of the membrane are positively charged. The inside of the membrane is negatively charged relative to the outside. Both sides of the membrane are negatively charged. The outside of the membrane is negatively charged relative to the inside.
The inside of the membrane is negatively charged relative to the outside
Which best describes an electrical current? A form of potential energy that can produce current A positively or negatively charged atom or molecule The opposition to the flow of electrical current across a membrane The movement of charged particles like ions
The movement of charged particles like ions
Which of the following statements are true about sodium? Na+ has more influence on the resting membrane potential than any other ion. The resting plasma membrane is much less permeable to Na+ than to K+. Na+ is about 12 times as concentrated in the ECF as in the ICF. Na+ is pumped into the cell by the Na+-K+ pump.
The resting plasma membrane is much less permeable to Na+ than to K+. Na+ is about 12 times as concentrated in the ECF as in the ICF.
Which of the following statements are true about sodium? The resting plasma membrane is much less permeable to Na+ than to K+. Na+ is about 12 times as concentrated in the ECF as in the ICF. Na+ is pumped into the cell by the Na+-K+ pump. Na+ has more influence on the resting membrane potential than any other ion.
The resting plasma membrane is much less permeable to Na+ than to K+. Na+ is about 12 times as concentrated in the ECF as in the ICF.
Some neurotransmitters can have either excitatory or inhibitory effects depending on which of the following? The thickness of the postsynaptic membrane The strength of the action potential The type of receptors on the postsynaptic cell The amount of neurotransmitter released
The type of receptors on the postsynaptic cell
The resting membrane potential is negative due to which of the following? Multiple Choice Electrolytes are equally distributed between the extracellular fluid on the outside of the plasma membrane and the intracellular fluid on the inside. There are more negatively charged particles on the outside of the membrane than on the inside. There are more negatively charged particles on the inside of the membrane than on the outside. The sodium-potassium pump adds more cations to the cell than it takes out.
There are more negatively charged particles on the inside of the membrane than the outside
If demyelination occurs, why don't action potentials occur at regions of the axon that were previously myelinated? A much thicker plasma membrane is present within these regions of the axon. These regions lack the appropriate concentration of voltage-gated sodium channels. These regions contain too high of a concentration of voltage-gated sodium channels to work appropriately. A much thinner plasma membrane is present within these regions of the axon.
These regions lack the appropriate concentration of voltage-gated sodium channels
Which statements characterize neurotransmitters? They are found in dendrites of postsynaptic neurons. They are synthesized by presynaptic neurons. They are released in response to stimulation. They bind to receptors and alter the physiology of the postsynaptic cell. They stimulate the opening of voltage-regulated gates at the postsynaptic membrane.
They are synthesized by presynaptic neurons. They are released in response to stimulation. They bind to receptors and alter the physiology of the postsynaptic cell.
Which statements characterize neurotransmitters? They are synthesized by presynaptic neurons. They stimulate the opening of voltage-regulated gates at the postsynaptic membrane. They bind to receptors and alter the physiology of the postsynaptic cell. They are released in response to stimulation. They are found in dendrites of postsynaptic neurons.
They are synthesized by presynaptic neurons. They bind to receptors and alter the physiology of the postsynaptic cell. They are released in response to stimulation.
Select all that apply Which statements are true about Schwann cells? They assist in the regeneration of damaged nerve fibers. They are only found in the central nervous system. They form the myelin sheath in the PNS. They form the neurilemma.
They assist in the regeneration of damaged nerve fibers. They form the myelin sheath in the PNS. They form the neurilemma.
True or false: Action potentials occur only where there are voltage-gated ion channels. True False
True
If acetylcholinesterase became mutated and nonfunctional, what would be the immediate result? Acetylcholine synthesis would immediately cease. Acetylcholine would build up in the synaptic cleft. Acetylcholine present in the synaptic cleft would no longer depolarize the postsynaptic membrane. Neurotransmitter-filled synaptic vesicles would be unable to fuse and release their products into the synaptic cleft.
acetylcholine would build up in the synaptic cleft
Where does saltatory conduction occur? Across chemical synapses Along unmyelinated nerve fibers Along myelinated nerve fibers Along dendrites
along myelinated nerve fibers
The neurotransmitters glutamate and GABA are examples of which of the following? Glycoproteins Amino acids Neuropeptides Bioamines
amino acids
The term "nerve fiber" refers to a(n) ________________ -axon -organ -nerve cell -bundle of macromolecules in the nerve cell -organelle in the nerve cells
axon
Which process of a neuron is specialized for rapid conduction of nerve signals to structures relatively far away from the neuron cell body? Dendrite Ganglia Perikaryon Axon
axon
Which process of a neuron is specialized for rapid conduction of nerve signals to structures relatively far away from the neuron cell body? Ganglia Perikaryon Axon Dendrite
axon
A neuron with one axon and one dendrite is structurally classified as a ______________________neuron.
bipolar
At the synaptic knob, voltage-gated ______________ channels open, thereby stimulating the synaptic vesicles to release their neurotransmitters by exocytosis. calcium potassium chloride sodium
calcium
Substances that cause facilitation of a neuron ____________________________. cause the neuron to fire that may not fire under the same circumstances in the absence of the facilitator continually create additional ligand-gated ion channels at the receptor region disable the trigger zone of the axon hillock, thereby preventing it from reaching threshold alter the resting membrane potential of a presynaptic neuron by making it hyperpolarized
cause the neuron to fire that may not fire under the same circumstances in the absence of the facilitator
The brain and spinal cord are components of the ______ nervous system, while the nerves and ganglia are components of the ______ nervous system. peripheral, central central, peripheral sympathetic, parasympathetic somatic, autonomic
central, peripheral
Demyelinating diseases cause a(n) ______________ in the conduction velocity of action potentials. increase decrease
decrease
_________________ are the processes of a neuron that usually receive signals from other neurons.
dendrites
During which part of the action potential do most voltage-gated sodium channels open? Depolarization Repolarization Hyperpolarization Resting membrane potential
depolarization
Which term refers to the upward change in membrane potential during an action potential? Hyperpolarization Repolarization Polarization Depolarization
depolarization
Which term refers to the upward change in membrane potential during an action potential? Repolarization Polarization Depolarization Hyperpolarization
depolarization
Motor, or ___________, neurons carry signals away from the CNS and they lead to effectors (muscle and gland cells).
efferent
Motor, or ______________, neurons carry signals away from the CNS and they lead to effectors (muscle and gland cells).
efferent
The glial cells that line cavities of the brain and spinal cord and secrete and circulate cerebrospinal fluid are ______.
ependymal cells
The plural form of ganglion is ______. gangliae ganglia gangliogia ganglions
ganglia
Action potentials occur ____________________________. in the unmyelinated regions of an axon in myelinated regions of an axon in both unmyelinated and myelinated regions of an axon and the dendrites
in the unmyelinated regions of an axon
What is the primary function of the myelin sheath? To transmit nerve signals to adjacent cells To insulate the dendrites of a neuron To increase the speed of signal conduction in the axon To help keep neurons warm
increase the speed of signal conduction in the axon
When voltage-gated sodium channels are open, sodium flows _____________ the neuron, making the inside of the cell more _______________. into; positive out of; negative into; negative out of; positive
into; positive
Graded potentials result from the opening of ________________. leakage channels voltage-gated channels ATP pumps ligand-gated channels
ligand-gated channels
Graded potentials result from the opening of ________________. voltage-gated channels leakage channels ligand-gated channels ATP pumps
ligand-gated channels
Which term refers to decremental changes in electrical potential along a dendrite or the soma? Action potentials Local potentials Synaptic potentials Resting potentials
local potentials
Which term refers to decremental changes in electrical potential along a dendrite or the soma? Local potentials Resting potentials Action potentials Synaptic potentials
local potentials
Neuroglial cells that act as macrophages within the CNS are ______. satellite cells astrocytes microglia ependymal cells
microglia
Which group of neurotransmitters are synthesized from amino acids by removal of the -COOH group? Neuropeptides Purines Monoamines Acetylcholine
monoamines
Neurons with numerous dendrites and a single axon are structurally classified as which of the following? Multipolar Unipolar Anaxonic Bipolar
multipolar
The picture shows the most common structural type of neuron. It contains one axon and multiple dendrites, and it is classified as a(n) ______ neuron.
multipolar
A traveling wave of excitation is known as a(n) ______________________ -depolarizing signal -nerve signal -graded potential -local potential -action potential
nerve signal
Which two organ systems are primarily responsible for coordinating the other bodily systems so as to maintain homeostasis? Nervous system Endocrine system Immune system Cardiovascular system
nervous and endocrine
Sensory, association and motor are the three classes of what? Ganglia Neuroglia Neurons Neurotransmitters
neurons
Sensory, association and motor are the three classes of what? Neurotransmitters Ganglia Neurons Neuroglia
neurons
Cholecystokinin and substance P are examples of which type of neurotransmitter? Neuropeptides Monoamines Biogenic amines Amino acids
neuropeptides
The ______ (the cell body of a neuron) gives rise to branch-like processes called ______, which are the primary sites for receiving signals from other neurons. dendrites, axons neurosoma, dendrites axons, dendrites neurosoma, axons
neurosoma, dendrites
Assume in a laboratory you were able to isolate a neuron and remove the Acetylcholine receptors from the postsynaptic membrane. The substance _________________ would no longer cause facilitation of this neuron. caffeine nicotine
nicotine
Which are usually found inside the cell body (or soma) of a mature neuron? Nucleus Synaptic vesicles Mitochondria Rough endoplasmic reticulum Centrioles
nucleus mitochondria rough endoplasmic reticulum
Taken together, the sensory and motor subdivisions make up which of the following? Sympathetic nervous system Parasympathetic nervous system Peripheral nervous system Central nervous system
peripheral nervous system
At a synapse, the neuron that responds to the neurotransmitter is the ______ neuron. postsynaptic presynaptic
postsynaptic
An inhibitory postsynaptic potential results from the opening of____________________. chloride and/or sodium channels sodium and/or potassium channels potassium and/or chloride channels
potassium and/ or chloride channels
At a synapse, the neuron that releases neurotransmitter is the ______ neuron. presynaptic postsynaptic
presynaptic
Graded potentials are produced within the _______________________ segment of a neuron. conductive transmissive receptive initial
receptive
Which term refers to the period of time after a nerve cell has responded to a stimulus in which it cannot be excited by a threshold stimulus? Inhibitory period Excitatory period Latent period Refractory period
refractory period
Which term refers to the period of time after a nerve cell has responded to a stimulus in which it cannot be excited by a threshold stimulus? Latent period Refractory period Inhibitory period Excitatory period
refractory period
The following information best describes the _____________ phase of an action potential. • A membrane potential reading of +10 mV• Inactivated voltage-gated sodium channels• Open voltage-gated potassium channels repolarization depolarization hyperpolarization resting
repolarization
Propagation of an action potential down a myelinated axon in which the action potential appears to "jump" from node to node is called ____________ conduction. Listen to the complete question
saltatory
Propagation of an action potential down a myelinated axon in which the action potential appears to "jump" from node to node is called __________________ conduction.
saltatory
Which term is used to describe signal conduction along a myelinated axon? Migratory Continuous Local Saltatory
saltatory
Which term is used to describe signal conduction along a myelinated axon? Saltatory Local Continuous Migratory
saltatory
In the PNS; surround somas of neurons in ganglia, provide electrical insulation, and regulate the chemical environment of neurons
satellite cells
The release of a neurotransmitter is an example of which physiological property exhibited by a neuron? Excitability Conductivity Secretion
secretion
Afferent neurons are ______ neurons. sensory motor
sensory
Which terms refers to the part of the PNS that carries signals from various receptors to the CNS? Sympathetic division Efferent nervous system Sensory division Autonomic Nervous System
sensory division
Normally, sodium and potassium leakage channels differ because ___________________. -sodium leakage channels are voltage-gated, but potassium leakage channels are ligand-gated -sodium leakage channels require ATP to transport ions, but potassium leakage channels do not -sodium ions diffuse through leakage channels into the cell, but potassium ions diffuse through leakage channels out of the cell -sodium leakage channels always remain open, but potassium leakage channels must be specifically activated to open
sodiium ions diffuse through leakage channels into the cell, but potassium ions diffuse through leakage channels out of the cell.
Why is sodium more concentrated in the ECF than in the ICF of most neurons? The neuronal membrane is more permeable to potassium than it is to sodium at rest. Potassium and sodium are both cations. There are no ion channels in the neuronal membrane. Sodium is actively pumped out of the cell by transporter proteins.
sodium is actively pumped out of the cell by transporter proteins
The sensory and motor divisions of the peripheral nervous system are further split into which two subdivisions? Autonomic and voluntary Somatic and visceral Proximal and distal Spinal cord and brain
somatic and visceral
The sensory division of the PNS is further subdivided into the ______ sensory division, which carries signals from receptors in the skin, muscles, bones, and joints, and the ______ sensory division, which carries signals from organs of the thoracic and abdominal cavities. efferent, parasympathetic motor, sympathetic somatic, visceral visceral, somatic
somatic, visceral
The sensory division of the PNS is further subdivided into the ______ sensory division, which carries signals from receptors in the skin, muscles, bones, and joints, and the ______ sensory division, which carries signals from organs of the thoracic and abdominal cavities. motor, sympathetic efferent, parasympathetic visceral, somatic somatic, visceral
somatic, visceral
Which term refers to the microscopic physical gap between the presynaptic and postsynaptic neurons at a chemical synapse? Gap junction Axon terminal Synaptic cleft Synaptic vesicle
synaptic cleft
Which term applies to the small swellings at the distal end of the axon of a neuron that contain synaptic vesicles? Nodes of Ranvier Synaptic knobs Internodes Axon hillocks
synaptic knobs
What happens as a result of ion flow at a presynaptic terminal? Multiple Choice Synaptic vesicles migrate to the plasma membrane and release acetylcholine. Acetylcholine is passively transported from the presynaptic neuron. Acetylcholine is actively transported to the postsynaptic neuron. Ligand-gated sodium channels open. Sodium ions diffuse into the cell.
synaptic vesicles migrate to the plasma membrane and release acetylcholine
At its distal end, an axon has an extensive complex of fine branches called a(n) ______. synaptic vesicle terminal arborization dendrites axolemma
terminal arborization
anterograde goes from
the cell body to the synaptic knobs
retrograde goes from
the synaptic knobs to the cell body
Neurons with a single process extending from the soma, such as the neurons that carry sensory signals to the spinal cord, are classified structurally as ______ neurons. unipolar multipolar bipolar
unipolar
Which lists the structural categories of neurons? Afferent, association, and efferent Unipolar, bipolar, anaxonic, and multipolar Neurons, glia, satellite cells Sensory, motor, and interneurons
unipolar, bipolar, anaxonic, and multipolar
An axon lacking a myelin sheath is said to be ______. unmyelinated myelinated
unmyelinated
An action potential arriving at the presynaptic terminal causes what to occur? Multiple Choice Voltage-gated sodium ion channels open, and sodium ions diffuse into the cell. Voltage-gated sodium ion channels open, and sodium ions diffuse out of the cell. Voltage-gated calcium ion channels open, and calcium ions diffuse into the cell. Acetylcholine diffuses into the cell. Ligand-gated sodium channels open, and sodium ions diffuse out of the cell.
voltage-gated calcium ion channels open, and calcium ions diffuse into the cell
A cholinergic synapse uses which of the following as its neurotransmitter? Endorphin Acetylcholine Norepinephrine Serotonin
Acetylcholine
Select all that apply Select the four categories of neurotransmitters based on chemical composition. Acetylcholine Neuropeptides Sterols Glycoproteins Amino acids Monoamines
Acetylcholine Neuropeptides AminoAcids Monoamines
Which term describes all neurons that carry signals towards the CNS? Multiple Choice Afferent Efferent Motor Somatic Visceral
Afferent
An inhibitory local potential causes which of the following? A) Drifting of the membrane potential towards the resting membrane potential B) Hyperpolarization of the plasma membrane C) Repolarization of the plasma membrane D) Neutralization of the plasma membrane E) Depolarization of the plasma membrane
B) Hyperpolarization of the plasma membrane
Which are characteristics of local potentials? All-or-none Self-propagating Graded Decremental
Graded and Decremental
Why is myelin important? Check all that apply. Check All That Apply -It forms extensions called perivascular feet, which contact the blood capillaries and stimulate them to form a tight seal called the blood-brain barrier. -It speeds up signal conduction in the nerve fiber. -It produces cerebrospinal fluid. -It is formed to assist in the regeneration of damaged fibers. -It insulates the nerve fiber.
It speeds up signal conduction in the nerve fiber It is formed to assist in the regeneration of damaged fibers It insulates the nerve fiber
What is the primary function of the myelin sheath? To increase the speed of signal conduction in the axon To transmit nerve signals to adjacent cells To help keep neurons warm To insulate the dendrites of a neuron
To increase the speed of signal conduction in the axon
If the postsynaptic membrane potential reaches threshold level, an action potential will be produced. True or False
True
The enzyme acetylcholinesterase, located in the synaptic cleft and on the postsynaptic membrane, breaks ACh down into acetate and choline, thereby stopping the stimulation of a postsynaptic cell. True or False
True
The nerve impulse is an electrical current that travels along dendrites or axons. True or False
True
The physical basis of memory is a pathway through the brain called a memory trace, in which new synapses have formed or existing synapses have been modified to make transmission easier. True or False
True
The sodium-potassium pump is involved in establishing the resting membrane potential. True or False
True
True or False; Action potential never occurs in dendrites
True
When can a damaged peripheral nerve fiber regenerate? -When its soma is intact -When the fiber distal to the injury survives -When at leastsome neurilemma remains -When its soma is intact and the fiber distal to the injury survives -When its soma is intact and at least some of the neurilemma remains
When its soma is intact and at least some of the neurilemma remains.
A resting membrane potential of -70 mV indicates that the ________________. -negative ions will always move into a cell -positive ions outnumber the negative ions within the cytosol -negative ions are only present within the cytosol and are lacking in the extracellular fluid -charges lining the inside of the plasma membrane are negative compared to the charges lining the outside
charges lining the inside of the plasma membrane are negative compared to the charges lining the outside
The opening of _____________ gates produces an _______________ -sodium; IPSP -Calcium and sodium; IPSP -Chloride; IPSP -Calcium;IPSP -Potassium; EPSP
chloride; IPSP
The processes that branch from the somas of most neurons are called ______. dendrites nerves axons
dendrites
Two organ systems are dedicated to internal coordination, communication between the other systems, and maintaining the overall homeostasis of the body. They are the _____________system, which communicates by means of hormones, and the ______________ system which sends quick electrical and chemical messages from cell to cell.
endocrine nervous
What are the effectors of motor neurons? Muscle and gland cells Spinal cord and brain Skin and adipose tissue Sensory neurons
muscle and gland cells
What are the effectors of motor neurons? Spinal cord and brain Skin and adipose tissue Muscle and gland cells Sensory neurons
muscle and gland cells
What are the effectors of motor neurons? Spinal cord and brain Skin and adipose tissue Sensory neurons Muscle and gland cells
muscle and gland cells
Saltatory conduction means ______. "leaping" slow continuous inhibitory
"leaping"
How do neuromodulators alter synaptic transmission? -Altering the breakdown and/or reuptake of neurotransmitter -Increasing the release of neurotransmitters by presynaptic neurons -Adjusting the sensitivity of postsynaptic neurons to neurotransmitters -Promoting myelination by oligodendrocytes or Schwann cells
-Altering the breakdown and/or reuptake of neurotransmitter -Increasing the release of neurotransmitters by presynaptic neurons -Adjusting the sensitivity of postsynaptic neurons to neurotransmitters
The neurotransmitters glutamate and GABA are examples of which of the following? Glycoproteins Bioamines Neuropeptides Amino acids
Amino acids
Between the nodes of Ranvier are myelin-covered segments of axon encircled by Schwann cells. Which term refers to these segments? Internodes Synapses Axon collaterals Synaptic knobs
Internodes
Between the nodes of Ranvier are myelin-covered segments of axon encircled by Schwann cells. Which term refers to these segments? Synaptic knobs Internodes Axon collaterals Synapses
Internodes
Taken together, the sensory and motor subdivisions make up which of the following? Central nervous system Parasympathetic nervous system Peripheral nervous system Sympathetic nervous system
Peripheral nervous system
Which is true about a neuron with a large diameter, myelinated axon as compared to a neuron with a small diameter, unmyelinated axon? Less neurotransmitter will be released Signal conduction will be slower More neurotransmitter will be released Signal conduction will be faster
Signal conduction will be faster
Indicate the summative effect that brings the initial segment closest to threshold. Two IPSPs in proximity to each other Two EPSPs located a large distance apart Two EPSPs in proximity to each other Two IPSPs located a large distance apart One IPSP and one EPSP in proximity to each other
Two EPSPs in proximity to each other
Which term refers to the passage of proteins, organelles and other materials along an axon? Active transport Synaptic signaling Axonal transport Secretion
axonal transport
The knotlike swelling in a nerve where neuron cell bodies are found is called a(n) __________________________
ganglion
In electrical synapses, electrical signals move quickly from cell to cell through which of the following? Neurotransmitter receptors Gap junctions Na+-K+ pumps Voltage-gated ion channels
gap junctions
In electrical synapses, electrical signals move quickly from cell to cell through which of the following? Neurotransmitter receptors Voltage-gated ion channels Gap junctions Na+-K+ pumps
gap junctions
True or false: Action potentials occur only where there are voltage-gated ion channels. True False
true
Select all that apply How do neuromodulators alter synaptic transmission? Adjusting the sensitivity of postsynaptic neurons to neurotransmitters Altering the breakdown and/or reuptake of neurotransmitter Promoting myelination by oligodendrocytes or Schwann cells Increasing the release of neurotransmitters by presynaptic neurons
Adjusting the sensitivity of postsynaptic neurons to neurotransmitters Altering the breakdown and/or reuptake of neurotransmitter Increasing the release of neurotransmitters by presynaptic neurons
Which are properties of action potentials? All or none Graded (amplitude proportional to stimulus strength) Nondecremental (signal maintains amplitude) Self-propagating
All or none Nondecremental (signal maintains amplitude) Self-propagating
Sensory (afferent) neurons do which of the following? Receive incoming signals and initiate outgoing nerve signals Carry signals to muscles Carry signals to spinal cord and brain Carry signals to glands
Carry signals to spinal cord and brain
What are the two major anatomical subdivisions of the nervous system? Motor and sensory nervous systems Sympathetic and parasympathetic nervous systems Central and peripheral nervous systems Visceral and somatic nervous systems
Central and peripheral
The knotlike swelling in a nerve where neuron cell bodies are found is called a(n) ____________________
Ganglion
Which term refers to the outermost layer of myelin, containing the nucleus and cytoplasm of the Schwann cell? Axon collateral Gray matter Neurilemma Axon terminal
Neurilemma
Which term refers to the thick outermost coil of a Schwann cell? Endoneurium Oligodendrocyte Neurilemma Perineurium
Neurilemma
Which alter synaptic transmission by adjusting the sensitivity of postsynaptic neurons to neurotransmitters or by affecting the breakdown and/or removal of a neurotransmitter? Neuromodulators Cyclic AMP Myelin sheaths Calcium ions
Neuromodulators
Which term refers to the voltage difference (electrical potential) across the plasma membrane of a neuron when it is at rest and not engaged in electrical signaling? Local potential Action potential Resting membrane potential Postsynaptic potential
Resting membrane potential
Suppose that a new virus is discovered that specifically infects motor neurons. Assume that this virus enters neurons in conjunction with choline molecules. Once inside the cell, the virus enters the nucleus and replicates. Which direction describes the axonal transport route taken by this virus? Retrograde transport Anterograde transport
Retrograde transport
