A&P Chapter 12 Nervous system
98) ________ neurons are the most common neuron in the CNS. a) Multipolar b) Anaxonic c) Unipolar d) Bipolar e) none of the above
a) Multipolar
6) ___ neurons are the most common type of neurons. a) Multipolar b) Bipolar c) Unipolar d) Anaxonic e) Dendritic
a) Multipolar {internuerons or association)?
59) Aggregations of fixed and free ribosomes in neurons are referred to as a) Nissl bodies. b) Neurofibrils. c) Perikaryon. d) Microglia. e) Neurofilaments.
a) Nissl bodies.
75) The sodium-potassium exchange pump a) Requires ATP to function. b) Transports sodium ions into the cell during depolarization. c) Transports potassium ions out of the cell during repolarization. d) Moves sodium and potassium in the direction of their chemical gradients. e) Must reestablish ion concentrations after each action potential.
a) Requires ATP to function.
99) ________ neurons form the afferent division of the PNS. a) Sensory b) Neural sensory c) Somatic sensory d) Visceral sensory e) none of the above
a) Sensory
80) in which of the following would the rate of impulse conduction be the greatest a) a type A fiber b) a type B fiber c) a type C fiber d) a type D fiber e) a type E fiber
a) a type A fiber
93) neurons normally derive ATP solely through a) aerobic glycolysis b) anaerobic glycolysis c) formation of certain phosphate d) use of stored glycogen e) catabolism of DNA
a) aerobic glycolysis
30) ___ binds to ligand-regulated gates, and is the most common inhibitory neurotransmitter in the brain. a) aminobutyric acid (GABA). b) Noradrenaline c) Epinephrine d) Acetylcholine e) Norepinephrine
a) aminobutyric acid (GABA).
49) The most numerous glial cells in the central nervous system are the a) astrocytes. b) satellite cells. c) ependymal cells. d) microglia. e) oligodendrocytes.
a) astrocytes.
37) Opening of __ gates produces an ___. a) chloride; IPSP b) sodium; IPSP c) calcium; IPSP d) potassium; EPSP e) calcium and sodium; IPSP
a) chloride; IPSP
97) ________ neurons are rare, but occur in special sense organs. a) Multipolar b) Anaxonic c) Unipolar d) Bipolar e) none of the above
d) Bipolar
68) Neurons that have one axon and one dendrite are called a) Anaxonic. b) Tripolar. c) Unipolar. d) Bipolar. e) Multipolar
d) Bipolar.
66) Neurons that are small and offer no anatomical clues to distinguish axons from dendrites are called a) Anaxonic. b) Unipolar. c) Multipolar. d) Bipolar. e) Tripolar.
a) Anaxonic.
16) Most local potentials happen at the a) dendrites. b) axon hillock. c) trigger zone. d) Schwann cells.
a) dendrites.
13) Conduction speed of a nerve fiber would be the fastest in a a) large myelinated fiber. b) small myelinated fiber. c) large unmyelinated fiber. d) small unmyelinated fiber. e) small fiber with multiple Schwann cells.
a) large myelinated fiber
11) Most of the myelin sheath is composed of a) lipids. b) carbohydrates. c) glycoproteins. d) proteins. e) polysaccharides
a) lipids.
51) The myelin sheaths that surround the axons of some of the neurons in the CNS are formed by a) oligodendrocytes. b) microglia. c) astrocytes. d) satellite cells. e) ependymal cells.
a) oligodendrocytes.
3) Nerves are ___ of the nervous system. a) organs b) tissues c) organ systems d) organelles e) cells
a) organs
91) IPSPs (inhibitory postsynaptic potentials) a) result in local hyperpolarizations. b) prevent the efflux of potassium ions. c) prevent the efflux of calcium ions. d) increase membrane permeability to sodium ions. e) result in local depolarizations.
a) result in local hyperpolarizations.
34) All of these contribute to the cessation of the signal in a synaptic transmission except a) synaptic vesicles secrete neurotransmitter by exocytosis. b) neurotransmitter escapes from the synapse into the nearby extracellular fluid. c) neurotransmitters stop being released. d) the synaptic knob reabsorbs some neurotransmitters by endocytosis. e) enzymes in the postsynaptic cell break down some neurotransmitters.
a) synaptic vesicles secrete neurotransmitter by exocytosis.
78) During saltatory conduction, a) Action potentials move in all directions along an axon. b) Action potentials occur at successive nodes along the length of the stimulated axon. c) Local currents depolarize adjacent areas of membrane so that action potentials continue to form along the membrane. d) Local potentials produce a continuous outward flow of potassium ions. e) Action potentials produce a local current that is strong enough to spread along the length of the axon.
b) Action potentials occur at successive nodes along the length of the stimulated axon.
82) The ion needed to initiate the release of acetylcholine into the synaptic cleft is a) Chloride. b) Calcium. c) Sodium. d) Potassium. e) Zinc.
b) Calcium.
61) Branches that sometimes occur along the length of an axon are called a) Synapses. b) Collaterals. c) Hillocks. d) Synaptic knobs. e) Telodendria.
b) Collaterals.
73) Opening of sodium channels in the membrane of a neuron results in a) Hyperpolarization. b) Depolarization. c) Reestablishing the resting potential. d) Increased negative charge inside the membrane. e) Repolarization.
b) Depolarization.
60) The axon is connected to the soma by the a) Collaterals. b) Hillock. c) Synaptic knobs. d) Telodendria. e) Synapse
b) Hillock.
65) The rabbis virus can travel to the CNS via a) Axoplasmic transport b) Retrograde flow c) Blood vessels d) Connective tissue e) CSF
b) Retrograde flow
70) Sensory neurons of the PNS are a) Tripolar. b) Unipolar. c) Bipolar. d) Anaxonic. e) Multipolar
b) Unipolar.
95) Deteriorating changes at the distal segment of an axon as a result of a break between it and the soma is called ________ degeneration. a) Central b) Wallerian c) Peripheral d) Neural e) Conduction
b) Wallerian
38) Which of these is an example of an EPSP in a typical neuron? a) a voltage change from 0 mV to +0.35 mV b) a voltage change from -70 mV to -69.5 mV c) a voltage change from -69.5 mV to -70 mV d) a voltage change from +35 mV to 0 mV e) a voltage change from -70 mV to -70.5 mV
b) a voltage change from -70 mV to -69.5 mV
29) A cholinergic synapse employs ___ as its neurotransmitter. a) monoamine b) acetylcholine c) epinephrine d) norepinephrine e) catecholamine
b) acetylcholine
46) The part of the peripheral nervous system that brings information to the central nervous system is a) autonomic. b) afferent. c) somatic. d) motor. e) efferent
b) afferent.
4) Some ___ neurons are specialized to detect stimuli, whereas ____ neurons send signals to the effectors of the nervous system. a) efferent; afferent b) afferent; efferent c) motor; sensory d) efferent; association e) afferent; association
b) afferent; efferent
12) The myelin sheath is formed by a) fibers. b) cells. c) macromolecules. d) polymers. e) organelles
b) cells.
42) Parkinson disease is a progressive loss of motor function due to the degeneration of specific neurons. These neurons secrete an inhibitory neurotransmitter that prevents excessive activity in motor centers of the brain. This neurotransmitter is a) serotonin. b) dopamine. c) acetylcholine. d) GABA (.-aminobutyric acid). e) glutamate (glutamic acid
b) dopamine.
20) An inhibitory local potential a) depolarizes the plasma membrane. b) hyperpolarizes the plasma membrane. c) repolarizes the plasma membrane. d) neutralizes the plasma membrane. e) drifts the membrane potential towards the resting membrane potential.
b) hyperpolarizes the plasma membrane.
47) Which of the following is not a function of the neuroglia? a) support b) information processing c) isolation of neurons d) phagocytosis e) secretion of cerebrospinal fluid
b) information processing
53) Small phagocytic cells that are especially obvious in damaged tissue in the CNS are the a) ependymal cells. b) microglia. c) oligodendrocytes. d) astrocytes. e) satellite cells.
b) microglia.
56) Which of the following is not a glial cell of the nervous system? a) ependymal cells b) neurons c) Schwann cells d) satellite cells e) microglia
b) neurons
24) When the voltage of a plasma membrane shifts from +35mV towards 0 mV, we say the cell is a) depolarizing. b) repolarizing. c) hyperpolarizing. d) reaching the threshold. e) exiting the threshold.
b) repolarizing.
48) Each of the following is a type of glial cell found in the central nervous system, except a) ependymal cells. b) satellite cells. c) microglia. d) astrocytes. e) oligodendrocytes.
b) satellite cells.
55) Glial cells found surrounding the cell bodies of peripheral neurons are a) oligodendrocytes. b) satellite cells. c) ependymal cells. d) microglia. e) astrocytes
b) satellite cells.
90) EPSPs (excitatory postsynaptic potentials) occur when a) more potassium ions than usual leak out of a cell. b) sodium channels are opened. c) hyperpolarizations occur. d) more calcium ions than usual leak out of a cell. e) chloride ions enter a cell.
b) sodium channels are opened.
8) Most metabolic and regulatory functions in a neuron happen at the a) axon. b) soma. c) dendrites. d) axon hillock. e) Schwann cell
b) soma.
33) Some antidepressant drugs act by inhibiting monoamine oxidase (MAO), which is an enzyme a) that binds to chloride gates. b) that breaks down monoamines. c) that blocks sodium channels. d) that converts ATP to cyclic AMP. e) that degrades acetylcholine.
b) that breaks down monoamines.
79) Which of the following does not influence the time necessary for a nerve impulse to be transmitted? a) length of the axon b) whether the axon is sensory or motor c) presence or absence of a myelin sheath d) presence or absence of nodes e) diameter of the axon
b) whether the axon is sensory or motor
32) Which of these happens first in an adrenergic synaptic transmission? a) ATP is converted to cyclic AMP b) adenylate cyclase is activated c) G protein dissociates from the NE receptor d) G protein binds to adenylate cyclase e) cyclic AMP induces several effects in the cell
c) G protein dissociates from the NE receptor
74) Voltage-regulated channels can be found a) On the soma of neurons. b) On the surface of dendrites. c) In the membrane that covers axons. d) At the motor end plate. e) Along the perikaryon of neurons
c) In the membrane that covers axons.
54) The neurilemma of axons in the peripheral nervous system is formed by a) astrocytes. b) microglia. c) Schwann cells. d) oligodendrocytes. e) satellite cells.
c) Schwann cells.
64) The site of intercellular communication between neurons is the a) Collateral. b) Hillock. c) Synapse. d) Synaptic knob. e) Telodendria.
c) Synapse.
62) Axons terminate in a series of fine extensions known as a) Synapses. b) Collaterals. c) Telodendria. d) Synaptic knobs. e) Hillocks.
c) Telodendria.
1) ____ division carries signals to the smooth muscle in the large intestine. a) Visceral sensory b) Somatic sensory c) Visceral motor d) Somatic motor e) Afferent
c) Visceral motor
40) The best type of neural pool for producing a prolonged output is a) a converging circuit. b) a diverging circuit. c) a reverberating circuit. d) a presynaptic pool. e) an autonomic pool
c) a reverberating circuit.
44) The brain and spinal cord comprise the ________ nervous system. a) autonomic b) peripheral c) central d) afferent e) efferent
c) central
19) Local potentials are _____, meaning they vary in magnitude according to the strength of the stimulus. a) graded b) reversible c) decremental d) excitatory e) inhibitory
c) decremental
17) Opening of sodium gates typically leads to a) repolarization of the plasma membrane. b) hyperpolarization of the plasma membrane. c) depolarization of the plasma membrane. d) drifting of plasma membrane voltage toward a more negative value. e) plasma membrane voltage returning to the resting membrane potential.
c) depolarization of the plasma membrane.
22) Local potentials are ___, whereas action potentials are ___. a) irreversible; reversible b) self-propagating; local c) graded; all or none d) nondecremental; decremental e) produced by voltage-regulated channels; produced by gated channels
c) graded; all or none
36) Inhibitory postsynaptic potentials (IPSPs) are associated with a) depolarization of the cell membrane. b) repolarization of the cell membrane. c) hyperpolarization of the cell membrane. d) no change of the cell membrane potential. e) no change of the threshold.
c) hyperpolarization of the cell membrane.
45) Voluntary control of skeletal muscles is provided by the ________ nervous system. a) sympathetic b) parasympathetic c) somatic d) autonomic e) afferent
c) somatic
39) A neuron can receive thousands of EPSPs from different neurons, and responds by triggering or not triggering an action potential. This addition and response to the net effect of postsynaptic potentials is called a) temporal summation. b) neural summation. c) spatial summation. d) neuronal coding. e) recruitment.
c) spatial summation.
28) All of the following are typical characteristics of neurotransmitters except a) they are synthesized by a presynaptic neuron. b) they are released in response to stimulation. c) they are released into the bloodstream before reaching the postsynaptic cell. d) they bind to specific receptors on the postsynaptic cell. e) they alter the physiology of the postsynaptic cell
c) they are released into the bloodstream before reaching the postsynaptic cell.
84) The following are the steps involved in transmission at a cholinergic synapse. 1. Chemically regulated sodium channels on the postsynaptic membrane are activated. 2. Calcium ions enter the synaptic knob. 3. Acetylcholine is degraded by acetylcholinesterase. 4. An action potential depolarizes the synaptic knob at the presynaptic membrane. 5. The synaptic knob reabsorbs choline. 6. Acetylcholine is released from storage vesicles by exocytosis. 7. Acetylcholine binds to receptors on the postsynaptic membrane. 8. Calcium ions are removed from the cytoplasm of the synaptic knob. The correct sequence for these events is a) 4, 2, 6, 7, 8, 5, 3, 1. b) 2, 4, 6, 7, 1, 8, 3, 5. c) 2, 5, 4, 6, 7, 1, 8, 3. d) 4, 2, 6, 7, 1, 8, 3, 5. e) 6, 4, 2, 7, 1, 8, 3, 5.
d) 4, 2, 6, 7, 1, 8, 3, 5.
35) ___ excites skeletal muscle and inhibits cardiac muscle. a) Norepinephrine b) Dopamine c) Histamine d) Acetylcholine e) ß-endorphin
d) Acetylcholine
2) _______ are examples of effectors of the nervous system. a) Receptors b) Stimuli c) Reflexes d) Glands e) Sense organs
d) Glands
69) Neurons that have several dendrites and a single axon are called a) Unipolar. b) Anaxonic. c) Bipolar. d) Multipolar. e) Tripolar.
d) Multipolar.
10) ___ form myelin in the spinal cord. a) Schwann cells b) Astrocytes c) Satellite cells d) Oligodendrocytes e) Microglia
d) Oligodendrocytes
67) Neurons in which dendritic and axonal processes are continuous and the soma lies off to one side are called a) Anaxonic. b) Tripolar. c) Multipolar. d) Unipolar. e) Bipolar
d) Unipolar.
26) A traveling wave of excitation is what we know as a) a local potential. b) a graded potential. c) an action potential. d) a nerve signal. e) a depolarizing signal.
d) a nerve signal.
7) Nerve fiber refers to a) a nerve cell. b) an organelle in nerve cells. c) an organ. d) an axon. e) a bundle of macromolecules in nerve cells
d) an axon.
94) Interneurons a) carry only sensory impulses. b) carry only motor impulses. c) only connect motor neurons to other motor neurons. d) are found only in the central nervous system. e) are found between neurons and their effectors.
d) are found only in the central nervous system.
81) Which type of synapse dominates the nervous system? a) mechanical b) radioactive c) processing d) chemical e) electrical
d) chemical
43) Each of the following is a function of the nervous system, except a) coordinating voluntary and involuntary activities. b) integrating sensory information. c) providing sensation of the internal and external environments. d) directing activities that continue for extended periods, such as growth and pregnancy. e) regulating or controlling peripheral structures and systems.
d) directing activities that continue for extended periods, such as growth and pregnancy.
18) Which of the following will cause the plasma membrane to hyperpolarize when at its RMP? a) inflow of sodium b) inflow of potassium c) inflow of calcium d) inflow of chloride e) outflow of chloride
d) inflow of chloride
72) Membrane channels that are always open are called ________ channels. a) local b) regulated c) gated d) passive e) active
d) passive (leak)
23) During hyperpolarization; a) sodium ions are entering the cells. b) sodium ions are leaving the cell. c) potassium ions are entering the cell. d) potassium ions are leaving the cell. e) both sodium and potassium ions are leaving the cell.
d) potassium ions are leaving the cell.
31) Which of these happens first in an cholinergic synaptic transmission? a) acetylcholine diffuses across the synaptic cleft b) postsynaptic potential is produced c) sodium enters the postsynaptic cell d) synaptic vesicles release acetylcholine e) acetylcholine binds to ligand-regulated gates
d) synaptic vesicles release acetylcholine
87) The effect that a neurotransmitter has on the postsynaptic membrane depends on a) the quantity of neurotransmitters released. b) the nature of the neurotransmitter. c) the frequency of neurotransmitter release. d) the characteristics of the receptors. e) both A and B
d) the characteristics of the receptors.
14) In order for a peripheral nerve fiber to regenerate it must have a) all dendrites intact. b) at least half the length of the fiber intact. c) at least the entire axon and neurilemma intact. d) the soma and at least some neurilemma intact. e) at least part of the soma intact.
d) the soma and at least some neurilemma intact.
71) At the normal resting potential of a typical neuron, its ion exchange pump transports a) 3 intracellular sodium ions for 1 extracellular potassium ion. b) 1 intracellular sodium ion for 2 extracellular potassium ions. c) 3 extracellular sodium ions for 2 intracellular potassium ions. d) 2 intracellular sodium ions for 1 extracellular potassium ion. e) 3 intracellular sodium ions for 2 extracellular potassium ions
e) 3 intracellular sodium ions for 2 extracellular potassium ions
86) The following is a list of the steps that occur during transmission at an adrenergic synapse. 1. cAMP activates an enzyme that opens the chemically regulated sodium channels. 2. Norepinephrine is inactivated by the enzyme COMT. 3. Norepinephrine binds to receptors on the postsynaptic membrane. 4. An action potential depolarizes the synaptic knob. 5. Calcium ions enter the synaptic knob. 6. cAMP is activated. 7. Norepinephrine is released from the presynaptic membrane. The proper sequence of these events is a) 4, 7, 3, 6, 5, 1, 2. b) 6, 1, 4, 5, 7, 3, 2. c) 7, 3, 4, 5, 6, 1, 2. d) 5, 7, 3, 6, 1, 2, 4. e) 4, 5, 7, 3, 6, 1, 2
e) 4, 5, 7, 3, 6, 1, 2
83) Cholinergic synapses release the neurotransmitter a) Serotonin. b) GABA. c) Norepinephrine. d) Adrenalin. e) Acetylcholine
e) Acetylcholine
96) The axoplasm of the axon contains which of the following a) Neurotubules b) Mitochondria c) Lysosomes d) Neurofibrils e) All of the above
e) All of the above
76) The all-or-none principle states that a) Only motor stimuli can activate action potentials. b) The greater the magnitude of the stimuli, the greater the intensity of the action potential. c) Only sensory stimuli can activate action potentials. d) All stimuli will produce identical action potentials. e) All stimuli great enough to bring the membrane to threshold will produce identical action potentials.
e) All stimuli great enough to bring the membrane to threshold will produce identical action potentials.
9) ____ are the primary site for receiving signals from other neurons. a) Synaptic knobs b) Axons c) Axon collaterals d) Somas e) Dendrites
e) Dendrites
27) What would be the best explanation for why myelinated fibers conduct signals faster than unmyelinated fibers? a) There are no internodes in unmyelinated fibers. b) There are more internodes in unmyelinated fibers. c) Facilitated diffusion of sodium and potassium is faster in myelinated fibers. d) Active transport of sodium and potassium is faster in myelinated fibers. e) Diffusion of ions along the axoplasm is faster.
e) Diffusion of ions along the axoplasm is faster.
77) During continuous conduction, a) Action potentials move in all directions along an axon. b) Action potentials produce a local current that is strong enough to spread along the length of the axon. c) Local potentials produce a continuous outward flow of potassium ions. d) Action potentials occur at successive nodes along the length of the stimulated axon. e) Local currents depolarize adjacent areas of membrane so that action potentials continue to form along the membrane.
e) Local currents depolarize adjacent areas of membrane so that action potentials continue to form along the membrane
100) ________ account for roughly half of the volume of the nervous system. a) Dendrites b) Axons c) Efferent fibers d) Synapses e) Neuroglia
e) Neuroglia
57) Cells responsible for information processing and transfer are the a) Microglia. b) Neuroglia. c) Astrocytes. d) Schwann cells. e) Neurons.
e) Neurons.
85) Adrenergic synapses release the neurotransmitter a) Acetylcholine. b) GABA. c) Serotonin. d) Dopamine. e) Norepinephrine
e) Norepinephrine
58) The cytoplasm surrounding the nucleus of a neuron is called a a) Protoplasm b) Nucleoplasm c) Sarcoplasm d) Cytoplasm e) Perikaryon
e) Perikaryon
15) ___ has the greatest influence on the resting membrane potential. a) Sodium b) Chloride c) Calcium d) Phosphate e) Potassium
e) Potassium
63) Neurotransmitters are released from the a) Hillock. b) Collaterals. c) Telodendria. d) Synapse. e) Synaptic knobs
e) Synaptic knobs
5) About 90% of the neurons in the nervous system are ___ neurons. a) sensory b) motor c) afferent d) efferent e) association
e) association (interneurons)
89) which of the following is not a possible drug effect on synaptic function a) interfere with neurotransmitter synthesis b) alter the rate of neurotransmitter release c) prevent neurotransmitter inactivation d) prevent neurotransmitter binding to receptors e) change the type of neurotransmitter found in the synaptic vesicle
e) change the type of neurotransmitter found in the synaptic vesicle
41) Even though all action potentials are the same, the brain can differentiate a variety of stimuli by source and intensity. The mechanism by which the nervous system converts these action potentials into meaningful information is called neural a) recruitment. b) pooling. c) integration. d) facilitation. e) coding.
e) coding.
52) The type of glial cell that is found lining the ventricles and spinal canal are the a) oligodendrocytes. b) microglia. c) satellite cells. d) astrocytes. e) ependymal cells.
e) ependymal cells.
50) Functions of astrocytes include all of the following, except a) maintaining the blood-brain barrier. b) performing repairs in damaged neural tissue. c) creating a three-dimensional framework for the CNS. d) guiding neuron development. e) functioning in action potential transmission.
e) functioning in action potential transmission.
25) During the absolute refractory period a) if a neuron reaches threshold, the action potential goes to completion. b) the neuron fires at its maximum voltage if a stimulus depolarizes the neuron to threshold. c) the signal grows weaker with distance. d) it is possible to trigger a new action potential, but only with an unusually strong stimulus. e) no stimulus of any strength will trigger a new action potential
e) no stimulus of any strength will trigger a new action potential
88) Which of the following is usually an excitatory neurotransmitter? a) DOPA b) gamma aminobutyric acid c) serotonin d) dopamine e) noradrenaline
e) noradrenaline
21) While the membrane is depolarizing its a) chloride gates are partially open. b) chloride gates are fully open. c) potassium gates are fully open. d) sodium gates are partially open. e) sodium gates are fully open.
e) sodium gates are fully open.
92) When a second EPSP arrives at a single synapse before the effects of the first have disappeared, what occurs? a) decrease in speed of impulse transmission b) inhibition of the impulse c) spatial summation d) hyperpolarization e) temporal summation
e) temporal summation
