Chapter 11 Nervous System

The firing of one neuron can produce temporal summation. a. True b. False

True

The presence of the nodes of Ranvier speeds up the velocity of conduction along the axon. a. True b. False

True

The space between the nerve cells is called the synapse. a. True b. False

True

Unipolar neurons are more accurately called pseudounipolar neurons. a. True b. False

True

Identify the neuronal circuit described by "many neurons influence a few neurons" a. converging b. diverging c. parallel after-discharge d. reverberating

a

Immediately after an action potential has peaked, which cellular gates open? a. potassium b. calcium c. sodium d. chloride

a

Which of the following substances plays the major role in generating the membrane potential of a neuron through its passive movement? a. urea b. potassium c. sodium d. chloride

b

Which of these ions is actively transported through the cell membrane to establish a resting potential? a. Ca b. Na c. Cl d. Mg

b

Nerve impulses leading to the brain carry information about cool temperatures on the skin. The nerve fibers sending these signals will most likely belong to which division of the nervous system? sensory (afferent) division somatic nervous system sympathetic division parasympathetic division

A

These cells in the CNS have cilia that move in order to circulate cerebrospinal fluid ________. ependymal cells Schwann cells oligodendrocytes astrocytes

A

What is the basic condition when a neuron is described as polarized? There is a separation of positive and negative charges across a membrane. Na+ is found outside of the neuron. Na+ is found outside of the neuron and K+ is found inside of the cell. There are large, protein anions inside the neuron.

A

Which of the following is not characteristic of neurons? They are mitotic. They have extreme longevity. They have an exceptionally high metabolic rate. They conduct impulses.

A

Which of the following types of glial cells monitors the health of neurons, and can transform into a special type of macrophage to protect endangered neurons? microglia ependymal cells oligodendrocytes astrocytes

A

Which is the main receptive portion of the neuron? the synapse the dendrite the cell body or soma the axon

B

Meningitis can be caused by infection of the central nervous system by bacteria. Which cells would be most responsible for removing the infection? satellite cells oligodendrocytes Schwann cells microglia

D

Nerve impulses are sent to slow the heart's rate of contraction. The nerve fibers sending these signals will most likely belong to which division of the nervous system? sensory (afferent) division somatic nervous system sympathetic division parasympathetic division

D

Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone? nitric oxide serotonin acetylcholine endorphin

D

Which of the following peripheral nervous system (PNS) neuroglia form the myelin sheaths around larger nerve fibers in the PNS? oligodendrocytes astrocytes satellite cells Schwann cells

D

A neuron becomes depolarized during an inhibitory postsynaptic potential (IPSP). a. True b. False

False

Acetylcholine is released only by neurons at neuromuscular junctions. a. True b. False

False

All neurons are amitotic. a. True b. False

False

Although a variety of molecules act as neurotransmitters, amino acid neurotransmitters have NOT yet been found. a. True b. False

False

Schwann cells myelinate axons in the CNS. a. True b. False

False

Strong stimuli cause the amplitude of action potentials generated to increase. a. True b. False

False

The CNS is the control center for ALL human activities. a. True b. False

False

The end of the nerve cell axon is called the dendrite. a. True b. False

False

The sodium-potassium pump provides energy for neurons, but does NOT affect resting membrane potential. a. True b. False

False

At an excitatory synapse, only one type of channel is opened, allowing both sodium and potassium to diffuse simultaneously in opposite directions. This still allows depolarization to take place. a. True b. False

True

Axons are the conducting component of the neuron, whereas dendrites are the collecting, or receptive, component. a. True b. False

True

Excitatory synapses can occur anywhere on a dendrite or soma, but it is at the axon hillock where an action potential can be generated. a. True b. False

True

Reflexes are rapid, automatic responses to stimuli that will produce the same effect every time. True False

True

The first thing needed to start an action potential is _____. a. a stimulus b. sodium c. potassium d. calcium

a

The sensory, or afferent, division of the peripheral nervous system transmits information from the __________ to the CNS. skin heart stomach kidney sweat glands

a

The specific period during which the potassium ions diffuse out of the neuron due to a change in membrane permeability is a. repolarization b. action potential c. depolarization d. relative refractory period e. absolute refractory period

a

There are two types of synapses: chemical and _____. a. electrical b. dendritic c. axonical d. mechanical

a

What is the difference between nerves and tracts? Bundles of neuron processes are called tracts in the CNS and nerves in the PNS. Tracts are composed of many nerves wrapped into long, ropelike extensions. Bundles of neuron processes are called nerves in the CNS and tracts in the PNS. Tracts are bundles of neuron processes, and nerves are the conducting regions of neurons.

a

Which of the following circuit types is exemplified by impulses that travel from a single neuron of the brain, activate one hundred or more motor neurons in the spinal cord, and excite thousands of skeletal muscle fibers? diverging circuit parallel after-discharge circuit converging circuit reverberating circuit

a

Which of the following conditions would cause synaptic potentiation? influx of Ca++ influx of Na+ K+ efflux influx of Cl-

a

Which of the following diseases is directly related to demyelination? multiple sclerosis cerebral palsy lupus muscular dystrophy

a

Which of the following is NOT a biogenic amine neurotransmitter? acetylcholine dopamine norepinephrine epinephrine serotonin

a

Which of the following is NOT a characteristic of neurons? Neurons are relatively small, simple-structured cells. In general, neurons cannot be replaced if destroyed. Neurons require continuous and abundant supplies of oxygen, and cannot survive for more than a few minutes without it. Neurons can function optimally for over 100 years.

a

Which of the following is NOT a functional classification of neurotransmitters? chemical excitatory direct indirect

a

Which of the following is characteristic of an action potential? voltage-gated ion channels absent of positive feedback travels a short distance occurs in the dendrites and cell body

a

Which of the following neurotransmitters act(s) as a natural opiate? endorphins epinephrine GABA serotonin dopamine

a

Which of the following types of glial cells are the most abundant and versatile, and aid in making exchanges between capillaries and neurons? astrocytes oligodendrocytes microglial cells ependymal cells

a

Which part of the action potential occurs when the Na⁺ channels are inactivating and K⁺ channels open? a. repolarization b. depolarization c. hyperpolarization d. resting state

a

Which type of ion channel opens when a chemical binds to it? chemically gated (ligand-gated) channel leakage channel mechanically gated channel voltage-gated channel

a

Also called a nerve impulse transmitted by axons is a. repolarization b. action potential c. depolarization d. relative refractory period e. absolute refractory period

b

An action potential is regarded as an example of a positive feedback. Which of the following examples below best illustrates the positive feedback aspect of an action potential? The sodium potassium pump consistently moves ions as long as ATP is available, and regardless of membrane potential changes. A threshold stimulus will cause the opening of voltage gated sodium ion channels that will cause further depolarizing stimulus. This stimulus will open still more voltage gated sodium ion channels. Voltage gated potassium ion channels open slowly and remain open long enough to cause hyperpolarization. Potassium permeability is about 25 times greater than sodium ions.

b

Bacteria in the blood can be prevented entry to the fluids surrounding the brain. Which cells are most responsible for preventing bacteria from entering the fluids of the brain? satellite cells astrocytes Schwann cells oligodendrocytes

b

Identify the neuronal circuit described by "one or a few inputs ultimately influence large numbers of neurons" a. converging b. diverging c. parallel after-discharge d. reverberating

b

In a __________ circuit, multiple presynaptic neurons innervate a single postsynaptic neuron. reverberating converging parallel after-discharge diverging

b

Nerve impulses leading to the skeletal muscle carry information to direct movement. The nerve fibers sending these signals will most likely belong to which division of the nervous system? sensory (afferent) division somatic nervous system sympathetic division parasympathetic division

b

Neurons can be classified structurally by the number of processes extending from their cell bodies. Which of the following is the most common neuron type in humans? pseudounipolar multipolar unipolar bipolar Multipolar and bipolar neurons are present in equal proportions.

b

Spatial summation occurs when __________. multiple local potentials occur at different times in the same cell multiple local potentials occur at different places on the same cell at the same time multiple local potentials occur at the same synapse on a cell an EPSP from one terminal is activated several times in rapid order

b

The difference in charge between the inside of the nerve cell membrane and the outside is called _____. a. differential factor b. membrane potential c. stimulus d. none of the above

b

What component of the reflex arc determines the response to a stimulus? receptor integration center effector sensory neuron

b

What type of current flows through the axolemma during the steep phase of repolarization? a. chiefly a sodium current b. chiefly a potassium current c. sodium and potassium currents of approximately the same magnitude

b

Which criterion is used to structurally classify neurons? whether the nerve fibers are myelinated or not the number of processes extending from their cell body whether the neurons are found within the CNS or the PNS the direction the nerve impulse travels relative to the central nervous system

b

Which is best described by "lines brain cavities"? a. astrocyte b. ependymal cell c. microglial cell d. oligodendrocyte e. satellite cell f. Schwann cell

b

Which of the following best describes the nervous system function of integration? The nervous system causes a response by activating effector organs, such as the muscles and glands. The nervous system processes and interprets sensory input and decides what should be done at each moment. The nervous system generates neurons in order to replace or repair damaged neurons; this permits optimal communication between the CNS and the body's effector organs. The nervous system uses its millions of sensory receptors to monitor changes occurring both inside and outside the body.

b

Which of the following electrical events occurs when a certain threshold is reached? resting membrane potential action potential EPSP IPSP

b

Which of the following electrical events occurs when a certain threshold is reached? a. IPSP b. action potential c. resting membrane potential d. EPSP

b

Which of the following factors is associated with increased conduction velocity in an axon? increased number of dendrites large diameter presence of collaterals small diameter the absence of the myelin sheath

b

Which of the following membrane ion channels in the neuron are always open? mechanically gated channels leakage channels ligand-gated channels voltage-gated channels

b

Which of the following membrane ion channels open and close in response to changes in the membrane potential? mechanically gated channels voltage-gated channels chemically gated channels nongated channels

b

Which of the following statements best describes the resting membrane state in the neuron? Only the voltage-gated K+ are closed. All of the voltage-gated Na+ and K+ channels are closed. Only the voltage-gated Na+ channels are open. Only the voltage-gated Na+ channels are closed. Only the voltage-gated K+ channels are open.

b

Which of the following structures is not part of the central nervous system? a. the brain b. a nerve c. the spinal cord d. a tract

b

From where can collaterals emerge on a myelinated nerve? the dendrite the terminal of the axon the nodes of Ranvier the neuron hillock

c

A second nerve impulse cannot be generated until _____. a. The Na ions have been pumped back into the cell b. Proteins have been resynthesized c. The membrane potential has been re-established d. All sodium gates are closed

c

Which of the following types of glial cells line the central cavities of the brain and spinal cord, where they help to circulate the cerebrospinal fluid? astrocytes oligodendrocytes microglial cells ependymal cells

d

In a neuron, a membrane potential of -90 mV is considered __________. depolarized a graded potential hyperpolarized a normal resting potential

c

Organelles slated for degradation or recycling are moved through the axon by ___________. anterograde movement saltatory movement retrograde movement

c

The interior of the cell becomes less negative due to an influx of sodium ions is a. repolarization b. action potential c. depolarization d. relative refractory period e. absolute refractory period

c

What is the difference between the clusters of cell bodies called nuclei and those known as ganglia? Nuclei exist in all cells throughout the body, and ganglia exist only within the brain and spinal cord. Nuclei exist in the PNS, ganglia in the CNS. Nuclei exist in the CNS, ganglia in the PNS. There is no difference between nuclei and ganglia.

c

What is the primary difference between the somatic nervous system and the autonomic nervous system? The autonomic nervous system enables us to control our involuntary muscles, while the somatic nervous system controls our glands. The somatic nervous system enables us to control our involuntary muscles, while the autonomic nervous system controls our glands. The somatic nervous system allows us to consciously control our skeletal muscles, and the autonomic nervous system controls activity that humans cannot consciously control, such as the pumping of the heart and the movement of food through the digestive tract. The autonomic nervous system allows us to consciously control our skeletal muscles, and the somatic nervous system controls activity that humans cannot consciously control, such as the pumping of the heart and the movement of food through the digestive tract.

c

What type of stimulus is required for an action potential to be generated? a suprathreshold stimulus hyperpolarization a threshold level depolarization multiple stimuli

c

Which is best described by "CNA phagocyte"? a. astrocyte b. ependymal cell c. microglial cell d. oligodendrocyte e. satellite cell f. Schwann cell

c

Which of the following are the main receptive or input regions found in neurons? neurofibrils ganglia dendrites axons

c

Which of the following defines integration? monitoring changes both inside and outside the body increasing the level of one substance in response to a decrease in the level of another processing and interpreting sensory input and determining what should be done at each moment in the body activating effector organs

c

Which of the following divisions of the nervous system is also known as the involuntary nervous system? the peripheral nervous system the somatic nervous system the autonomic nervous system the spinal division of the nervous system

c

Which of the following explains the inability of a neuron to respond to a second stimulus of equal strength to the first stimulus to which it has already responded? Neurons are amitotic. Action potential generation is an all-or-none phenomenon. The neuron is in the absolute refractory period. The neuron is myelinated.

c

Which of the following is FALSE regarding motor (efferent) neurons? Motor (efferent) neurons carry impulses away from the CNS to the effector organs. The cell bodies of most motor (efferent) neurons are located in the CNS. Motor (efferent) neurons are bipolar. Impulses from motor (efferent) neurons cause activity in skeletal muscles and glands.

c

Which of the following is NOT true of chemical synapses? a. They communicate unidirectionally. b. They possess pre- and postsynaptic membranes separated by a synaptic cleft. c. They transmit nerve impulses directly from one neuron to another. d. Each is composed of an axon terminal and a receptor region.

c

Which of the following membrane ion channels open and close in response to changes in the membrane potential? a. mechanically gated channels b. chemically gated channels c. voltage-gated channels d. non-gated channels

c

Which of the following statements best describes the membrane situation in the resting state in the neuron? a. Only the voltage-gated Na⁺ channels are open. b. Only the voltage-gated Na⁺ channels are closed. c. All the voltage-gated Na⁺ and K⁺ channels are closed. d. Only the voltage-gated K⁺ are closed. e. Only the voltage-gated K⁺ channels are open.

c

Which of the following substances is NOT a neurotransmitter? carbon dioxide epinephrine acetylcholinesterase histamine

c

Which part of the action potential occurs when the voltage-gated Na+ channels are inactivating and voltage-gated K+ channels open? hyperpolarization resting state repolarization depolarization

c

An inhibitory postsynaptic potential (ISPS) is associated with _____. a. lowering the threshold for an action potential to occur b. opening of voltage-regulated channels c. a change in sodium ion permeability d. hyperpolarization

d

Caffeine's stimulatory effects result from blocking receptors for which neurotransmitter? a. acetylcholine b. serotonin c. dopamine d. adenosine

d

During which phase of an action potential are voltage-gated K+ channels open, while voltage-gated Na+ channels are closed? resting state threshold depolarization repolarization

d

During which phase of an action potential are voltage-gated K⁺ channels open, while voltage-gated Na⁺ channels are closed? a. regeneration b. depolarizing phase c. resting state d. repolarizing phase

d

Identify the neuronal circuit described by "impulses continue around and around the circuit until one neuron stops firing" a. converging b. diverging c. parallel after-discharge d. reverberating

d

The CNS can discriminate between strong and weak stimuli as strong stimuli __________. shift threshold increase the amplitude of action potentials hyperpolarize the neuron increase the frequency of action potentials

d

The Nissl bodies in the neuron cell body are otherwise known as which cellular organelle(s)? microtubules mitochondria nucleus rough endoplasmic reticulum centrioles

d

The movement of which ion out of the cell through leakage channels establishes the negative membrane potential? calcium sodium chloride potassium

d

The sodium-potassium ion pump will __________. pump one sodium ion out of the cell for every ion of potassium it brings into the cell pump three potassium ions out of the cell for every two sodium ions it brings into the cell pump one potassium ion out of the cell for every ion of sodium it brings into the cell pump three sodium ions out of the cell for every two ions of potassium it brings into the cell

d

The term central nervous system refers to the ________. the somatic nerves the spinal nerves sensory (afferent) nerves brain and spinal cord

d

Which is best described by "myelinates nerve fibers"? a. astrocyte b. ependymal cell c. microglial cell d. oligodendrocyte e. satellite cell f. Schwann cell

d

Which of the following circuit types is exemplified by impulses that travel from a single neuron of the brain, activate one hundred or more motor neurons in the spinal cord, and excite thousands of skeletal muscle fibers? a. converging circuits b. after-discharge circuits c. reverberating circuits d. diverging circuits

d

Which of the following events occurs at an electrical synapse? Neurotransmitters bind to the postsynaptic receptors. Calcium channels open in the presynaptic region. Neurotransmitters diffuse across the synaptic cleft. Ions flow directly from one neuron to the next. A neurotransmitter is released by exocytosis.

d

Which of the following is FALSE regarding chemical synapses? They possess pre- and postsynaptic membranes separated by a synaptic cleft. Each is composed of an axon terminal and a receptor region. They communicate unidirectionally. They transmit nerve impulses directly from one neuron to another.

d

Which of the following is NOT a function of the myelin sheath? to increase the speed of transmission of nerve impulses to protect nerve fibers to electrically insulate nerve fibers to recapture and recycle released neurotransmitters

d

Which of the following is NOT a structural classification of neurons? multipolar unipolar bipolar sensory

d

Which of the following is a rare type of sensory neuron that is found in special sensory structures such as the retina of the eye? unipolar pseudounipolar multipolar bipolar

d

Which of the following line the central cavities of the brain and spinal cord and provide a fairly permeable barrier between the CSF and nervous tissue? a. Schwann cells b. astrocytes c. oligodendrocytes d. ependymal cells e. microglia cells

d

Which of the following neuroglia are most responsible for helping determine capillary permeability in the central nervous tissue? Schwann cells oligodendrocytes microglial cells astrocytes ependymal cells

d

Which of the following statements about the developmental aspects of neurons is INCORRECT? a. Neurons that fail to make the appropriate synaptic contact will not receive appropriate nutrients and will die. b. They develop from neuroepithelial cells. c. Axons are attached to grow toward their "target" by multiple signals such as the nerve growth factor, the nerve cell adhesion factor, and older pathfinder neurons. d. The number of adult neurons is the same as the number formed during the embryonic period. e. Neuroepithelial cells become the CNS and then go through three phases of differentiation during maturation.

d

Which of the following statements concerning inhibitory synapses (IPSPs) is correct? The postsynaptic membrane becomes less permeable to sodium. The permeability of the postsynaptic membrane to sodium, potassium, and chloride is not changed. Channels allow both sodium and potassium ions to diffuse simultaneously through the membrane. The postsynaptic membrane becomes more permeable to potassium and chloride. The postsynaptic membrane becomes less permeable to potassium.

d

Relative to extracellular fluid, the interior of a neuron has a negative charge because __________. chloride ions are actively pumped into the cell potassium is actively pumped out of the cell sodium is actively pumped into the cell potassium is actively pumped into the cell potassium diffuses out of the cell

e

Which cells line the central cavities of the brain and spinal cord and provide a fairly permeable barrier between the CSF and nervous tissue? astrocytes oligodendrocytes Schwann cells microglia cells ependymal cells

e

Which of the following characteristics is NOT associated with a myelinated nerve fiber? formation by oligodendrocytes in the central nervous system formation by Schwann cells in the peripheral nervous system the presence of nodes of Ranvier rapid conduction of nerve impulses slow conduction of nerve impulses

e

Which is best described by "myelinates nerve fibers in the PNS"? a. astrocyte b. ependymal cell c. microglial cell d. oligodendrocyte e. satellite cell f. Schwann cell

f

A reverberating circuit involves an incoming signal that travels along a chain of neurons and quickly dies out. a. True b. False

false

An action potential is a phenomenon that either happens completely or doesn't happen at all. True False

true

Dendrites and axons are both armlike processes that extend from neuron cell bodies. True False End of Question 7

true

The most abundant neurotransmitter in the body is acetylcholine. a. True b. False

true