Chapter 12 Neural Tissue
1) Which of the following is not a function of the nervous system?
D) direct long-term functions, such as growth
2) The ________ nervous system is composed of the brain and spinal cord.
3) The ________ nervous system controls the skeletal muscles.
4) The part of the peripheral nervous system that carries sensory information to the CNS is designated
5) The efferent division of the peripheral nervous system innervates ________ cells.
E) All of the answers are correct
E) All of the answers are correct
6) The axoplasm of the axon contains which of the following?
E) All of the answers are correct
7) Which of the following is not a recognized structural classification for neurons?
D) pseudopolar
8) The most abundant class of neuron in the central nervous system is
C) multipolar
9) The cytoplasm that surrounds the nucleus of a neuron is called the
E) perikaryon
10) Clusters of RER and free ribosomes in neurons are called
D) Nissl bodies
11) The axon is connected to the soma at the
E) synapse.
D) axon hillock
12) Branches that may occur along an axon are called
C) collaterals
13) Axons terminate in a series of fine extensions known as
A) telodendria.
14) Neurotransmitters ready for release are stored in synaptic
C) vesicles
15) The site of intercellular communication between a neuron and another cell is the
E) synapse
16) The rabies virus travels to the CNS via
E) cerebrospinal fluid
B) retrograde axoplasmic transport
17) Neurons that are rare, small, and lack features that distinguish dendrites from axons are called
A) anaxonic.
18) Neurons in which dendritic and axonal processes are continuous and the soma lies off to one side are called
B) unipolar
19) Neurons that have one axon and one dendrite, with the soma in between, are called
E) multipolar
C) bipolar.
20) Neurons that have several dendrites and a single axon are called
E) multipolar.
21) Sensory neurons of the PNS are
E) tripolar.
A) unipolar
22) Which of the following activities or sensations is/are not monitored by interoceptors?
E) urinary activities
A) sight
23) ________ neurons are small and have no anatomical features that distinguish dendrites from axons.
B) Anaxonic
24) ________ neurons are short, with a cell body between dendrite and axon, and occur in special sense organs.
D) Bipolar
25) In a(n) ________ neuron, the dendrites and axon are continuous or fused.
C) unipolar
26) ________ neurons are the most common structural class in the CNS.
E) Sensory
A) Multipolar
27) ________ neurons form the afferent division of the PNS.
B) Sensory
28) ________ are the most numerous type of neuron in the CNS.
E) Interneurons
29) Most CNS neurons lack centrioles. This observation explains
B) why CNS neurons cannot divide to regenerate damaged tissue
30) How does blocking retrograde axoplasmic transport in an axon affect the activity of a neuron?
D) The soma becomes unable to respond to changes in the distal end of the axon
39) Deteriorating changes in the distal segment of an axon as a result of a break between it and the soma is called ________ degeneration.
D) Wallerian
40) Which of the following is not a function of the neuroglia?
B) memory
41) Which of the following is a type of glial cell found in the peripheral nervous system?
B) satellite cells
42) The largest and most numerous of the glial cells in the central nervous system are the
E) ependymal cells
A) astrocytes.
43) Functions of astrocytes include all of the following except
B) conducting action potentials.
44) ________ account for roughly half of the volume of the nervous system.
C) Neuroglia
45) The function of the astrocytes in the CNS includes which of the following?
E) All of the answers are correct
46) The neuroglial cells that participate in maintaining the blood-brain barrier are the
A) astrocytes
47) The myelin sheath that covers many CNS axons is formed by
C) oligodendrocytes
48) ________ line the brain ventricles and spinal canal.
E) Ependymal cells
49) Small, wandering cells that engulf cell debris and pathogens in the CNS are called
D) microglia
50) The neurilemma of axons in the peripheral nervous system is formed by
E) Schwann cells.
51) Glial cells that surround the neurons in ganglia are
B) satellite cells
52) Many medications introduced into the bloodstream cannot directly affect the neurons of the CNS because
E) astrocytes form a capsule around neurons.
B) the endothelium of CNS capillaries forms a blood-brain barrier.
53) Extensive damage to oligodendrocytes in the CNS could result in
E) loss of sensation and motor control
E) loss of sensation and motor control
54) Damage to ependymal cells would most likely affect the
E) transport of neurotransmitters within axons
B) formation of cerebrospinal fluid
55) When pressure is applied to neural tissue, all of the following effects are possible except
E) neurons are triggered to divide
E) neurons are triggered to divide
56) In the peripheral nervous system, Schwann cells participate in the repair of damaged nerves by
E) producing more satellite cells that fuse to form new axons.
C) forming a cellular cord that directs axonal regrowth.
57) After a stroke, what type of glial cell accumulates within the affected brain region?
D) microglia
58) Which of the following is not true regarding the establishment of a neuron's resting potential?
A) Chemical and electrical forces both favor sodium ions entering the cell.
B) Electrical forces push sodium ions into the cell.
C) The chemical gradient for potassium ions tends to drive them out of the cell.
D) Ion pumps in the plasma membrane eject sodium ions as fast as they cross the membrane.
E) Resting membrane permeability to Na+ is very low.
B) Electrical forces push sodium ions into the cell.
59) At the normal resting potential of a typical neuron, its sodium-potassium exchange pump transports
A) 1 intracellular sodium ion for 2 extracellular potassium ions.
B) 2 intracellular sodium ions for 1 extracellular potassium ion.
C) 3 intracellular sodium ions for 1 extracellular potassium ion.
D) 3 intracellular sodium ions for 2 extracellular potassium ions.
E) 3 extracellular sodium ions for 2 intracellular potassium ions.
D) 3 intracellular sodium ions for 2 extracellular potassium ions.
60) Ion channels that are always open are called ________ channels.
C) leak
61) Opening of sodium channels in the axon membrane causes
A) depolarization
62) Voltage-gated channels are present
C) in the membrane that covers axons
63) The sodium-potassium ion exchange pump
D) moves sodium and potassium opposite to the direction of their electrochemical gradients
64) Integral membrane proteins that connect electrical synapses are called
A) connexons
65) The equilibrium potential for potassium ion occurs at approximately
A) -90 mV
66) ________ open or close in response to binding specific molecules.
A) Leak channels
B) Activated channels
C) Chemically gated channels
D) Voltage-gated channels
E) Voltage-gated and chemically gated channels
C) Chemically gated channels
67) ________ channels open or close in response to physical distortion of the membrane surface.
D) Mechanically gated
68) Any stimulus that opens a ________ ion channel will produce a graded potential.
A) voltage-gated
B) chemically gated
C) sodium
D) mechanically gated
E) All of the answers are correct
E) All of the answers are correct
69) If the permeability of a resting axon to sodium ion increases,
E) inward movement of sodium will increase and the membrane will depolarize
E) inward movement of sodium will increase and the membrane will depolarize
70) Which of the following is not involved in creating the resting potential of a neuron?
A) diffusion of potassium ions out of the cell
B) diffusion of sodium ions into the cell
C) membrane permeability for sodium ions greater than potassium ions
D) membrane permeability for potassium ions greater than sodium ions
E) The interior of the plasma membrane has an excess of negative charges.
C) membrane permeability for sodium ions greater than potassium ions
71) If the sodium-potassium pumps in the plasma membrane fail to function, all of the following occur except
A) the intracellular concentration of potassium ions will increase
72) Graded potentials
E) cause repolarization
C) may be either a depolarization or a hyperpolarization.
73) When potassium channels open and the ions diffuse through the membrane,
E) the membrane will depolarize to threshold
B) the inside of the membrane will become more negative
74) Ions can move across the plasma membrane in which of the following ways?
E) All of the answers are correct
E) All of the answers are correct
75) Raising the potassium ion concentration in the extracellular fluid surrounding a nerve cell will have what effect?
E) both hyperpolarize it and decrease the magnitude of the potassium equilibrium potential
76) Voltage-gated sodium channels have both an activation gate and a(n) ________ gate.
A) inactivation
77) If acetylcholine (ACh) causes inhibition of a postsynaptic neuron, to what type of membrane channel did the ACh bind?
D) chemically-regulated potassium channel
78) A stimulus that changes a postsynaptic neuron's membrane from resting potential to -85 mV is a(n) ________ stimulus.
E) inhibitory
79) If the axolemma becomes more permeable to potassium ion,
B) a stronger stimulus will be required to cause an action potential.
80) The following are the main steps in the generation of an action potential.
What is the proper sequence of these events?
B) 4, 6, 7, 1, 2, 3, 5
81) The all-or-none principle states that
E) only motor stimuli can activate action potentials
82) The same ________ can have different effects depending on the properties of the ________.
A) neurotransmitter; receptor
83) Which of the following statements about the action potential is false?
A) The rapid depolarization phase is caused by the entry of potassium ions
84) How would the absolute refractory period be affected if voltage-regulated sodium channels failed to inactivate?
A) It would last indefinitely
85) During repolarization of a neuron
B) potassium ions move out of the cell
86) How would a chemical that prevents the opening of voltage-regulated Na+ channels affect the function of a neuron?
E) The neuron will only be capable of producing graded potentials.
E) The neuron will only be capable of producing graded potentials
87) A threshold stimulus is the
E) electrical current that crosses the synaptic cleft
A) depolarization necessary to cause an action potential
88) Which of the following is true about threshold for an action potential?
E) Threshold for a typical neuron is approximately -30 mV
A) It is more positive than the resting potentia
89) Puffer fish poison blocks voltage-gated sodium channels like a cork. What effect would this neurotoxin have on the function of neurons?
D) The axon would be unable to generate action potentials
99) Rapid impulse conduction from "node" to "node" is called
B) saltatory propagation
100) Which of the following does not influence the time necessary for a nerve impulse to be transmitted?
E) whether or not the impulse begins in the CNS
101) Which of the following types of nerve fiber possesses the fastest speed of impulse propagation?
A) type A
102) Type ________ fibers have the largest diameter axons.
C) A
103) Sensory information from skeletal muscles travels over ________ fibers.
A) type A
104) In which of the following would the rate of impulse conduction be the greatest?
E) It would be the same in all because of the all-or-none principle
A) a myelinated fiber of 10-µm diameter
105) A neuron that receives neurotransmitter from another neuron is called
E) the postsynaptic neuron
E) the postsynaptic neuron
106) Which type of synapse is most common in the nervous system?
A) chemical
107) The ion that triggers the release of acetylcholine into the synaptic cleft is
C) calcium
108) Cholinergic synapses release the neurotransmitter
D) acetylcholine
109) The following are the steps involved in transmission at a cholinergic synapse. What is the correct sequence for these events?
B) 4, 2, 6, 7, 1, 8, 3, 5
110) If the chemically gated sodium channels in the postsynaptic membrane were completely blocked,
A) synaptic transmission would fail
111) The effect that a neurotransmitter has on the postsynaptic membrane depends on the
E) All of the answers are correct
E) All of the answers are correct
112) When cholinergic receptors are stimulated,
E) norepinephrine deactivates acetylcholine
A) sodium ions enter the postsynaptic neuron.
113) If the axon terminal of a motor neuron suddenly became permeable to calcium ion,
B) the motor end plate will be depolarized.
114) Each of the following is an example of a synapse between neurons and effector cells except the junction between a neuron and a(n)
E) nerve cell
115) What triggers the release of acetylcholine from a synaptic terminal?
E) diffusion of calcium ions into the synaptic terminal
116) Adrenergic synapses release the neurotransmitter
B) norepinephrine
117) Which of the following is the most important excitatory neurotransmitter in the brain that is important in learning and memory?
E) glycine
A) glutamate
118) Which of the following is not a possible drug effect on synaptic function?
E) change the type of receptor found in the postsynaptic membrane
119) Opioids relieve pain by blocking the release of
B) substance P.
120) Which of the following is a recognized class of opioid neuromodulators?
E) All of the answers are correct
E) All of the answers are correct
121) Active neurons need ATP to support which of the following?
E) All of the answers are correct.
122) After acetylcholinesterase acts, the synaptic terminal
E) pinches off and a new terminal grows
C) reabsorbs the choline
123) A postsynaptic neuron will have an excitatory postsynaptic potential (EPSP) when
E) more potassium ions than usual diffuse out of the neuron
C) chemically regulated sodium channels are open and sodium is diffusing into the cell.
124) Presynaptic facilitation by serotonin is caused by
D) calcium channels in the presynaptic membrane remaining open longer.
125) The site in the neuron where EPSPs and IPSPs are integrated is the
C) axon hillock
126) EPSPs (excitatory postsynaptic potentials) occur when
D) extra sodium ions enter a cell
127) IPSPs (inhibitory postsynaptic potentials)
E) block the efflux of calcium ions.
B) are local hyperpolarizations
128) When a second EPSP (excitatory postsynaptic potential) arrives at a single synapse before the effects of the first have disappeared, what occurs?
B) temporal summation
129) Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated
A) spatial summation
1) The nervous tissue outside of the central nervous system composes the ________ nervous system.
B) peripheral
2) The ________ division of the peripheral nervous system brings sensory information to the central nervous system.
D) afferent
3) The ________ division of the nervous system carries motor commands to muscles and glands.
E) efferent
4) The ________ nervous system provides involuntary regulation of smooth muscle, cardiac muscle, and glandular activity.
C) autonomic
5) ________ carry motor information to peripheral effectors.
E) Interneurons
B) Efferent neurons
6) ________ nerves are nerves that connect to the spinal cord.
A) Spinal
7) ________ nerves are nerves that connect to the brain.
D) Cranial
8) ________ monitor the position of skeletal muscles and joints
A) Proprioceptors
9) ________ carry sensory information to the CNS.
D) Afferent neurons
10) ________ provide information about the external environment.
E) Proprioceptors
D) Exteroceptors
11) ________ monitor the digestive, respiratory, cardiovascular, urinary, and reproductive systems.
A) Spinal nerves
B) Unipolar neurons
C) Internoceptors
D) Exteroceptors
E) Proprioceptors
C) Internoceptors
12) The plasma membrane of an axon is called the
E) axolemma
13) The basic functional unit of the nervous system is the
E) receptor
A) neuron
14) The most common neuron of the nervous system is the
E) microglial cell.
A) interneuron.
15) Most neurons lack ________ and so are permanently blocked from undergoing cell division.
D) centrioles
16) Products from the soma of a neuron are transported to the synaptic terminals by ________ transport.
A) anterograde
17) A change in the conditions in the synaptic terminal can influence the soma as a result of ________ transport.
B) retrograde
18) Neuron cell bodies in the PNS are clustered together in masses called
E) ganglia
E) ganglia
19) The tiny gaps between adjacent Schwann cells are called
E) vesicles.
B) nodes of Ranvier
20) Regions of the CNS with an abundance of myelinated axons constitute the ________ matter.
B) white
21) Regions of the CNS where neuron cell bodies dominate constitute the ________ matter.
B) gray
22) A movement of charges in response to a potential difference is called
E) electricity
A) current
23) The separation of positive and negative charges across the membrane creates a ________ difference, or voltage.
E) potential
24) The sum of the electrical and chemical forces acting on an ion is known as its
E) summation difference
C) electrochemical gradient
25) A shift of the resting transmembrane potential toward 0 mV is called
B) depolarization
26) The minimum stimulus required to trigger an action potential is known as the
A) threshold
27) The ________ principle states that the size and speed of the action potential are independent of the stimulus strength.
E) potential
B) all-or-none
28) The period during which an excitable membrane cannot respond to further stimulation is the ________ period.
B) absolute refractory
29) The period during which an excitable membrane can respond again, but only if the stimulus is greater than the threshold stimulus, is the ________ period.
A) relative refractory
30) The presence of ________ dramatically increases the speed at which an action potential moves along an axon.
E) myelin
31) The sensory loss and muscle weakness associated with multiple sclerosis are a consequence of
E) too few nodes of Ranvier
B) demyelination
32) At a(n) ________ synapse, a neurotransmitter is released to stimulate the postsynaptic membrane.
C) chemical
33) In a(n) ________ synapse, current flows directly between cells.
A) electrical
34) Compounds that alter the rate of neurotransmitter release by the presynaptic neuron or change the postsynaptic cell's response to neurotransmitters are called
D) neuromodulators
35) The buildup of depolarization when EPSPs arrive in rapid succession is called ________ summation.
E) perforal
A) temporal
36) The buildup of depolarization when EPSPs arrive at several places on the neuron is called ________ summation.
B) spatial