PHYSIO: chapter 7 practice questions
57. The average resting membrane potential of an axon is A. -70mV. B. -85mV. C. 0 mV D. +30mV.
A. -70mV.
64. An axon will depolarize only if the membrane potential reaches between -70mV and - 55mV. This follows the A. All-or-none law. B. recruitment law. C. graduated law. D. threshold law.
A. All-or-none law.
189. Which of the following is NOT true of long-term potentiation (LTP)? A. Associated with the removal of AMPA glutamate receptors B. Repeated stimulation enhance excitability C. Associated with insertion of AMPA glutamate receptors D. It is a form of synaptic plasticity
A. Associated with the removal of AMPA glutamate receptors
85. ______ synapses occur between axons of presynaptic cells and dendrites of postynaptic cells. A. Axodendritic B. Axosomatic C. Myoneural D. Axoaxonic
A. Axodendritic
156. Benzodiazepines act by increasing ________ activity. A. GABA B. glutamate C. ACh D. enkephalin
A. GABA
77. What is NOT true of the relative refractory period? A. Na+ channels are inactivated B. many Na+ channels are returning to a closed state C. K+ is moving out of the axon through its open channels D. a strong stimulus could cause a depolarization
A. Na+ channels are inactivated
122. ____________ is an acetylcholinesterase antagonist used to treat myasthenia gravis. A. Neostigmine B. Muscarine C. Naloxone D. Nitric oxide
A. Neostigmine
28. The myelin sheaths of PNS neurons are produced by A. Schwann cells. B. oligodendrocytes. C. ependymal cells. D. leukocytes.
A. Schwann cells.
173. What medication acts by increasing the action of nitric oxide as a treatment for erectile dysfunction? A. Viagra B. marijuana C. Prozac D. naloxone
A. Viagra
121. What is the action of the binding of muscarine to its receptors in the digestive system? A. alpha subunits bind to K+ channels, close them, leading to depolarization. B. alpha subunits bind to K+ channels, open them, leading to hyperpolarization. C. beta-gamma subunits bind to K+ channels, close them, leading to depolarization. D. beta-gamma subunits bind to K+ channels, open them, leading to hyperpolarization.
A. alpha subunits bind to K+ channels, close them, leading to depolarization.
45. The most numerous of all cells of CNS nervous tissue are the A. astrocytes. B. neurons. C. Schwann cells. D. microglia
A. astrocytes.
5. The brain and spinal cord comprise the A. central nervous system. B. peripheral nervous system. C. peripheral ganglia. D. spinal nerves.
A. central nervous system.
90. What type of proteins are present in gap junctions that form water-filled channels between neurons? A. connexins B. myelin C. terminal boutons D. cell adhesion molecules (CAMs)
A. connexins
167. The brain produces lipid neurotransmitters called A. endocannabinoids. B. endorphins. C. enkephalins. D. nitric oxide.
A. endocannabinoids.
94. Botulism toxin prevents release of ACh, causing A. flaccid paralysis. B. hemiplegia. C. spastic paralysis. D. None apply.
A. flaccid paralysis.
87. Chemical synapses A. have a delayed impulse transmission. B. utilize gap junctions. C. occur when two nerve cells are in direct contact with each other. D. do not require the release of neurotransmitters
A. have a delayed impulse transmission.
184. Enhancing the excitability of a synapse so that transmission is favored along certain pathways is called A. long-term potentiation. B. synaptic plasticity. C. excitotoxicity. D. summation.
A. long-term potentiation.
25. Which type of cell of the CNS is phagocytotic? A. microglia B. satellite cells C. ependymal cells D. oligodendrocytes
A. microglia
17. Which of the following is NOT a structural classification of neurons? A. motor neuron B. bipolar neuron C. multipolar neuron D. pseudounipolar neuron
A. motor neuron
38. Regeneration of CNS axons may be prevented in part by inhibitory proteins in the membranes of the A. myelin sheath. B. neurons. C. astrocytes. D. satellite cells.
A. myelin sheath.
36. White matter is A. myelinated axons in the CNS. B. myelinated axons in the PNS. C. nonmyelinated cell bodies and dendrites in the CNS. D. nonmyelinated axons in the CNS.
A. myelinated axons in the CNS.
165. The most abundant neuropeptide in the brain is A. neuropeptide Y. B. neuropeptide Z. C. substance P. D. CCK.
A. neuropeptide Y.
170. Relaxation of cerebral blood vessels would be stimulated by excessive ________ activity. A. nitric oxide B. acetylcholine C. norepinephrine D. glutamate
A. nitric oxide
145. Addictive drugs, as well as nicotine, activate dopamine release in the A. nucleus accumbens. B. corpus striatum. C. basal nuclei. D. corpus callosum.
A. nucleus accumbens.
146. The mesolimbic dopamine neurons arise in the midbrain and terminate in the A. nucleus accumbens. B. corpus striatum. C. basal nuclei. D. corpus callosum.
A. nucleus accumbens.
178. Temporal summation A. occurs when a single neuron releases neurotransmitter rapidly. B. occurs because of the convergence of many neurons on a single postsynaptic cell. C. only involves excitatory postsynaptic potentials. D. only involves inhibitory postsynaptic potentials.
A. occurs when a single neuron releases neurotransmitter rapidly.
126. What type of autonomic fibers release ACh at effectors? A. parasympathetic B. sympathetic C. somatic D. sensory
A. parasympathetic
140. What neurotransmitter is used by neurons with cell bodies in the raphe nuclei along the midline of the brainstem? A. serotonin B. dopamine C. glycine D. GABA
A. serotonin
111. Muscarinic ACh receptors are found in all of the following locations EXCEPT A. skeletal muscle B. smooth muscle C. cardiac muscle D. glands
A. skeletal muscle
157. Which poison inhibits glycine receptors? A. strychnine B. curare C. tetrodotoxin D. All of the choices are correct.
A. strychnine
10. Which of the following is NOT true of dendrites? A. transmits action potentials toward the cell body B. are thin extensions of the cell body C. transmit graded electrochemical impulses toward the cell body D. contain receptive areas
A. transmits action potentials toward the cell body
129. What is present at the axon hillock that allows the production of action potentials? A. voltage-gated channels B. ligand-gated channels C. muscarinic receptors D. chemical-gated channels
A. voltage-gated channels
117. Muscarinic ACh receptors act through ____________ activation of K+ channels. A. cGMP B. G-protein C. M-protein D. ATP
B. G-protein
112. What do muscarine and nicotine have in common? A. They are both antagonists for their respective receptors. B. They are both agonists for their respective receptors. C. They both activate-protein coupled channels. D. They have nothing in common.
B. They are both agonists for their respective receptors.
124. Cholinergic fibers use ____ as the neurotransmitter. A. norepinephrine B. acetylcholine C. dopamine D. serotonin
B. acetylcholine
16. Sensory neurons A. are multipolar and carry impulses toward the CNS. B. are pseudounipolar and carry impulses toward the CNS. C. are bipolar and carry impulses away from the CNS. D. are multipolar and carry impulses away from the CNS.
B. are pseudounipolar and carry impulses toward the CNS.
119. Acetylcholine can induce hyperpolarization by A. binding to nicotinic receptors. B. binding to muscarinic receptors. C. binding to -adrenergic receptors. D. binding to -adrenergic receptors.
B. binding to muscarinic receptors.
96. Neurotransmitter release would be inhibited by A. stimulating repolarization of the axon terminal. B. blocking Ca2+ influx in the axon terminal. C. blocking repolarization of the axon terminal. D. stimulating protein kinase activity.
B. blocking Ca2+ influx in the axon terminal.
43. Gliotransmitters A. include calcium ions. B. can stimulate neurons. C. form the blood-brain barrier. D. break down ATP.
B. can stimulate neurons.
180. Excitotoxicity is caused by A. insufficient synaptic release of glutamate. B. excessive synaptic release of glutamate. C. GABA inhibition. D. insufficient synaptic release of ACh.
B. excessive synaptic release of glutamate
186. Synaptic plasticity involves structural changes in neurons such as A. formation of axillary branches B. formation of dendritic spines C. formation of more axon terminals D. mitosis of neurons
B. formation of dendritic spines
151. Excitatory postsynaptic potentials are produced by A. glycine. B. glutamic acid. C. gamma-aminobutyric acid. D. benzodiazepines.
B. glutamic acid.
185. What process occurs when glutamate-releasing presynaptic neurons stimulate postsynaptic release of endocannabinoids that acts as retrograde neurotransmitters? A. long-term potentiation B. long-term depression C. depolarization-induced suppression of inhibition D. All apply.
B. long-term depression
141. The __________ dopamine system may be involved in emotional reward and drug addiction. A. nigrostriatal B. mesolimbic C. amygdala D. dentate
B. mesolimbic
150. Which of the following is NOT a type of glutamate receptor? A. NMDA receptor B. muscarinic receptor C. kainate receptor D. All of the choices are correct.
B. muscarinic receptor
161. The normal effect of -endorphin can be blocked by A. curare. B. naloxone. C. muscarine. D. nicotine
B. naloxone.
74. Repolarization is accomplished through a A. positive feedback loop. B. negative feedback loop. C. relative refractory loop. D. sodium equilibrium potential.
B. negative feedback loop.
118. Acetylcholine usually induces an excitatory postsynaptic potential when binding to ________ receptors and an inhibitory postsynaptic potential when binding to some ____________ receptors. A. NMDA, nicotinic B. nicotinic, muscarinic C. muscarinic, NMDA D. muscarinic, nicotinic
B. nicotinic, muscarinic
35. The gap of exposed axon in the myelin sheath is the A. neurilemma. B. node of Ranvier. C. sheath of Schwann. D. white matter.
B. node of Ranvier.
177. Spatial summation A. occurs when a single neuron releases neurotransmitter rapidly. B. occurs because of the convergence of many neurons on a single postsynaptic cell. C. only involves excitatory postsynaptic potentials. D. only involves inhibitory postsynaptic potentials.
B. occurs because of the convergence of many neurons on a single postsynaptic cell.
26. The myelin sheaths of CNS neurons are produced by A. Schwann cells. B. oligodendrocytes. C. ependymal cells. D. leukocytes.
B. oligodendrocytes.
63. The mechanism that allows many Na+ ions to move into the axon is A. negative feedback. B. positive feedback. C. equilibrium feedback. D. None of the choices are correct.
B. positive feedback.
168. Endocannabinoids are retrograde neurotransmitters, meaning they are A. released from presynaptic neurons and diffuse to the postsynaptic neuron. B. released from postsynaptic neurons and diffuse to the presynaptic neuron. C. released from presynaptic neurons and diffuse back to the presynaptic cell body. D. None apply.
B. released from postsynaptic neurons and diffuse to the presynaptic neuron.
82. Conduction of an action potential in a myelinated axon is called A. point to point conduction. B. saltatory conduction. C. refractory conduction. D. cable conduction.
B. saltatory conduction.
171. Nitric oxide A. is a chemical messenger activating adenylate cyclase. B. stimulates the dilation of blood vessels. C. is produced from L-asparagine. D. All apply.
B. stimulates the dilation of blood vessels.
183. The varied strength of synaptic transmission is called A. spatial summation. B. temporal summation. C. synaptic plasticity. D. EPSP.
B. synaptic plasticity.
65. The minimum depolarization needed to open Na+ gates is called the A. repolarization. B. threshold. C. refractory period. D. All-or-none law.
B. threshold.
138. MAO inhibitors may cause hypertensive crisis by a person eating foods rich in A. phenylalanine. B. tyramine. C. glutamic acid. D. tryptophan.
B. tyramine.
133. What amino acid are dopamine, norepinephrine, and epinephrine derived from? A. histidine B. tyrosine C. tryptophan D. serine
B. tyrosine
58. Ion channels that open in response to depolarization are called A. ion-gated channels. B. voltage-gated channels. C. stimulation-gated channels. D. potential-gated channels.
B. voltage-gated channels.
181. Both long-term potentiation and long-term depression requires release of ___ from the postsynaptic neuron membrane. A. Cl- B. K+ C. Ca2+ D. Mg2+
C. Ca2+
152. Which of the following is NOT an action needed for glutamate to open ion channels? A. NMDA receptor must bind to glycine B. the membrane must be partially depolarized from the action of a different neurotransmitter C. Cl- must pass through the open channel D. Mg2+ is released from NMDA channel to open it
C. Cl- must pass through the open channel
60. Blocking ____________ channels would prevent neuron depolarization. A. K+ B. Cl- C. Na+ D. Mg2+
C. Na+
61. During an action potential A. Na+ efflux causes depolarization. B. K+ influx causes repolarization. C. Na+ influx causes depolarization. D. K+ influx causes after-hyperpolarization.
C. Na+ influx causes depolarization.
70. What process is needed to return a membrane to its resting membrane potential with all ions in the correct locations? A. after-hyperpolarization B. all-or-none-law C. Na+/K+ pump D. refractory period
C. Na+/K+ pump
115. Which of the following is NOT true of nicotinic-gated channels? A. The binding of ACh allows diffusion of Na+ into and K+ out of the neuron. B. Only EPSPs are generated. C. Only action potentials are generated. D. Summation can occur because of a graded response.
C. Only action potentials are generated.
80. Action potentials would be conducted most rapidly by A. a 10 mm diameter myelinated axon. B. a 10 mm diameter unmyelinated axon. C. a 40 mm diameter myelinated axon. D. a 40 mm diameter unmyelinated axon.
C. a 40 mm diameter myelinated axon.
135. Which of the following is NOT true of histamine? A. it is derived from the amino acid histidine B. acts as a hormone that stimulates gastric secretion C. acts as a neurotransmitter in the brain to cause drowsiness D. acts as a regulator in inflammation and allergies
C. acts as a neurotransmitter in the brain to cause drowsiness
48. Which cells are needed for the formation of synapses in the CNS? A. ependymal B. microglia C. astrocytes D. dendrites
C. astrocytes
50. The blood-brain barrier results mostly from the action of __________, a type of glial cell. A. ependymal cells B. microglia C. astrocytes D. oligodendrocytes
C. astrocytes
21. Which division of the nervous system innervates involuntary effectors? A. central nervous system B. somatic nervous system C. autonomic nervous system D. associative nervous system
C. autonomic nervous system
62. Local anesthetics block conduction of action potentials in sensory neurons by A. inhibiting the release of acetylcholine. B. binding to potassium channels. C. binding to sodium channels. D. binding to calcium channels.
C. binding to sodium channels.
84. In a myelinated axon, Na+ channels are A. along the whole length of the axon. B. every 5 mm. C. concentrated at the nodes of Ranvier. D. less numerous at the nodes of Ranvier.
C. concentrated at the nodes of Ranvier.
190. What type of neural pathway involves one neuron forming synapses with several postsynaptic neurons? A. convergent B. oscillating C. divergent D. plastic
C. divergent
144. Neuroleptics, which are used to treat schizophrenia, are A. dopamine agonists. B. ACh antagonists. C. dopamine antagonists. D. glutamate agonists.
C. dopamine antagonists.
27. Which type of cell lines the ventricles of the brain and help produce cerebrospinal fluid? A. microglia B. satellite cells C. ependymal cells D. oligodendrocytes
C. ependymal cells
149. Mutation of the N-methyl-D-aspartate (NMDA) receptor would affect the ability of ____________ to regulate neural function. A. acetylcholine B. epinephrine C. glutamate D. nitric oxide
C. glutamate
132. Which of the following is NOT classified as a catecholamine? A. norepinephrine B. epinephrine C. histamine D. dopamine
C. histamine
154. Where is glycine released? A. in the PNS B. at skeletal muscleds C. in the CNS D. at the diaphragm
C. in the CNS
71. What coding system do neurons use to get a greater response? A. greater amplitude of stimuli B. greater Na+ concentration gradient C. increased frequency of stimuli D. more active Na+/K+ pump
C. increased frequency of stimuli
128. At what region of the neuron are action potentials first produced? A. dendrites B. cell body C. initial segment of an axon D. axon hillock
C. initial segment of an axon
39. The disease ______________ is characterized by destruction of CNS myelin sheaths and the formation of hardened scars. A. Parkinson's B. Alzheimer's C. multiple sclerosis. D. myasthenia gravis
C. multiple sclerosis.
18. Which of the following is NOT a functional classification of neurons? A. motor or efferent B. interneuron or association C. multipolar D. sensory or afferent
C. multipolar
30. What structure is found around PNS axons that is NOT found around CNS axons? A. nodes of Ranvier B. myelin sheath C. neurilemma D. plasma membrane
C. neurilemma
86. Chemicals that stimulate action potentials in postsynaptic cells are called A. hormones. B. enzymes. C. neurotransmitters. D. neurotrophins
C. neurotransmitters.
41. Fetal neuron growth requires the actions of a group of chemicals known as A. endorphins. B. synapsins. C. neurotrophins. D. glutamates.
C. neurotrophins.
11. Which of the following is true of axons? A. contain receptive areas B. very thin and short C. originates at the axon hillock on the cell body D. transmits graded electrochemical impulses
C. originates at the axon hillock on the cell body
69. Which ion's movements is responsible for repolarization? A. influx of K+ B. influx of Na+ C. outward diffusion of K+ D. outward diffusion of Na+
C. outward diffusion of K+
78. The ability of a neuron to transmit charge through its cytoplasm is called cable properties and is very A. good. B. strong. C. poor. D. easy.
C. poor.
55. The membrane of resting nerve cells is more permeable to ____________ ions than ____________ ions. A. sodium, potassium B. calcium, potassium C. potassium, sodium D. chloride, potassium
C. potassium, sodium
175. What type of receptors will bind ATP and adenosine? A. cotransmitter receptors B. pyrimenergic receptors. C. purinergic receptors. D. None apply.
C. purinergic receptors.
72. As the intensity of a stimulus increases, more axons will become activated. This process is called A. threshold. B. refraction. C. recruitment. D. None apply.
C. recruitment.
29. Cells supporting neuron cell bodies in ganglia are termed A. astrocytes. B. ependymal cells. C. satellite cells. D. Schwann cells.
C. satellite cells.
116. What is the predominant affect of stimulation of nicotinic-gated channels? A. stimulation due to outflow of K+ ions B. inhibition due to outflow of K+ ions C. stimulation due to influx of Na+ ions D. inhibition due to influx of Cl- ions
C. stimulation due to influx of Na+ ions
102. Which of the following is NOT true of EPSPs? A. they are graded responses B. they are capable of summation C. they have a refractory period D. they are initiated by neurotransmitters
C. they have a refractory period
23. A bundle of axons in the CNS is called a/an A. nerve. B. bundle. C. tract. D. neuron.
C. tract.
137. Serotonin is synthesized from the amino acid A. alanine. B. glycine. C. tryptophan. D. serine.
C. tryptophan.
99. Neurotransmitters A. are released by endocytosis. B. all bind to the same receptor. C. usually regulate ion channels. D. are actively transported across the synaptic cleft.
C. usually regulate ion channels.
162. Which of the following are natural analgesics? A. endorphins B. enkephalins C. dynorphins D. All apply.
D. All apply.
174. ATP and adenosine can act as neurtransmitters A. by being released from astrocytes. B. as cotransmitters. C. as paracrine regulators. D. All apply.
D. All apply.
187. What causes presynaptic inhibition? A. inactivation of Ca2+ channels B. a second neuron causes a reduction in neurotransmitter release from another neuron C. axoaxonic synapses D. All apply.
D. All apply.
9. Retrograde transport A. moves toward the cell body. B. moves membranes, vesicles, and viruses. C. uses molecular motor proteins of dynein. D. All apply.
D. All apply.
100. The binding of a neurotransmitter to its receptor protein causes ion channels to open in the post-synaptic membrane. What type of gates are these? A. chemically-regulated gates B. voltage-regulated gates C. ligand-regulated gates D. Chemically-regulated gates and ligand-regulated gates are correct.
D. Chemically-regulated gates and ligand-regulated gates are correct.
182. Postsynaptic inhibition is caused by A. acetylcholine B. GABA C. glycine D. GABA and glycine
D. GABA and glycine
158. The most common neurotransmitter in the brain is A. glycine. B. acetylcholine. C. serotonin. D. GABA.
D. GABA.
98. Hyperpolarization in the postsynaptic cell is caused by A. excitatory postsynaptic potentials. B. inhibitory postsynaptic potentials. C. movement of K+ out of the cell. D. Inhibitory postsynaptic potentials and movement of K+ out of the cell are correct.
D. Inhibitory postsynaptic potentials and movement of K+ out of the cell are correct.
22. What type of neuron is found entirely in the CNS? A. sensory neuron B. interneuron C. association neuron D. Interneuron and association neuron are correct.
D. Interneuron and association neuron are correct.
68. The period of time when Na+ channels are recovering from their inactive state and K+ channels are still open is the A. repolarization. B. absolute refractory period. C. relative refractory period. D. Repolarization and relative refractory period are correct.
D. Repolarization and relative refractory period are correct.
92. Synaptic vesicles are docked to the plasma membrane of the axon terminal by a protein complex called A. boutons. B. connexins. C. synaptotagmins. D. SNARE.
D. SNARE.
34. Action potential transmission in the PNS is decreased if which cells are damaged? A. astrocytes B. microglia C. oligodendrocytes D. Schwann cells
D. Schwann cells
110. Acetylcholine A. is always an excitatory neurotransmitter. B. can bind to adrenergic receptors. C. is an inhibitory neurotransmitter released by motor neurons. D. can bind to nicotinic receptors.
D. can bind to nicotinic receptors.
148. Which of the following is NOT true of norepinephrine? A. released in both the CNS and PNS B. released by sympathetic neurons to smooth muscle, cardiac muscle, and glands C. amphetamines stimulate norepinephrine pathways D. causes depression in the CNS
D. causes depression in the CNS
91. What type of proteins are present at chemical synapses to ensure the close proximity of the presynaptic and postsynaptic membranes? A. connexins B. myelin C. terminal boutons D. cell adhesion molecules (CAMs)
D. cell adhesion molecules (CAMs)
101. Which of the following effect(s) acetylcholine synaptic transmission? A. curare B. botulinum toxin C. strychnine D. curare and botulinum toxin.
D. curare and botulinum toxin.
42. Degeneration of spinal motor neurons in adults may be due to a lack of ____________ factor. A. brain-derived neurotrophic (BDNF) B. neurotrophin-3 C. nerve growth (NGF) D. glial-derived neurotrophic (GDNF)
D. glial-derived neurotrophic (GDNF)
139. Catecholamines activate postsynaptic cells by A. inhibition of adenylate cyclase. B. increased Ca2+ influx into the target cell. C. inhibition of calmodulin. D. increased production of cyclic AMP.
D. increased production of cyclic AMP.
166. Inhibition of neuropeptide Y synthesis would A. induce euphoria. B. induce obesity. C. stimulate leptin secretion. D. inhibit eating.
D. inhibit eating.
7. Which of the following is NOT true of axonal transport? A. uses molecular motors B. can transport anterograde or retrograde C. has one fast and two slow components D. is a passive process
D. is a passive process
169. Endogenous cannabinoids have effects similar to the active ingredient in A. cocaine. B. nicotine. C. amphetamines. D. marijuana.
D. marijuana.
40. Axonal regeneration is inhibited by A. brain-derived neurotrophic factor. B. nerve growth factor. C. neurotrophin-3. D. myelin-associated inhibitory protein.
D. myelin-associated inhibitory protein.
123. Curare is a competitive ACh antagonist at _____________ ACh receptors. A. muscarinic B. NMDA C. kainate D. nicotinic
D. nicotinic
172. Which gas(es) can function as a neurotransmitter? A. carbon dioxide B. nitric oxide C. carbon monoxide D. nitric oxide and carbon monoxide.
D. nitric oxide and carbon monoxide.
104. What action produces an IPSP on the postsynaptic membrane? A. influx of Na+ ions B. opening of Ca2+ channels into the neuron C. outflow of K+ ions D. opening of Cl- channels into the neuron
D. opening of Cl- channels into the neuron
46. Which of the following is NOT a function of astrocytes? A. can take up NT from a synapse B. can stimulate or inhibit neurons C. needed to form synapses in the CNS D. phagocytose foreign material in the CNS E. form the blood-brain barrier
D. phagocytose foreign material in the CNS
44. Which of the following is NOT a function of neurotrophins? A. maintaining sympathetic ganglion B. sustaining neurons that use the NT dopamine C. embryonic development of neurons D. regeneration of injured motor neurons
D. regeneration of injured motor neurons
159. The capacity of synapses for alteration at the molecular level is termed as A. synaptic modulation. B. synaptic alteration. C. synaptic capacitance. D. synaptic plasticity.
D. synaptic plasticity.
120. If the binding of muscarine to its receptor in the heart causes the beta-gamma complex of the G-protein to bind to a K+ channel, A. the K+ channel will close, leading to depolarization. B. the K+ channel will open, leading to depolarization. C. the K+ channel will close, leading to hyperpolarization and inhibition. D. the K+ channel will open, leading to hyperpolarization and inhibition.
D. the K+ channel will open, leading to hyperpolarization and inhibition.
130. What is NOT true of conduction through dendrites and cell bodies of neurons? A. they are EPSPs B. they are spread by cable properties C. they can summate to reach threshold D. they are action potentials
D. they are action potentials
1. The nerve is the basic structural and functional unit of the nervous system.
FALSE
103. Ligand-gated channels, when activated, allow only Na+ to move into the neuron.
FALSE
105. Once an EPSP is created on the postsynaptic neuron, a new action potential is produced down the axon.
FALSE
109. In a ligand-gated channel, the neurotransmitter receptor and the channel are separate proteins.
FALSE
113. Atropine is an antagonist to nicotine.
FALSE
114. Nicotinic receptors utilize G-proteins to regulate the opening of ion channels.
FALSE
12. Axonal transport from the cell body to the dendrites and axon is retrograde transport.
FALSE
127. Release of ACh at parasympathetic effectors is always stimulatory.
FALSE
14. Sensory nerves cause muscle contraction.
FALSE
142. The nigrostriatal dopamine system is located in part of the midbrain known as the substantia nigra and is degenerated in the disease myasthenia gravis.
FALSE
147. Cocaine blocks the release of dopamine, norepinephrine, and serotonin.
FALSE
155. Glycine is released at extensor muscles when flexor muscles are contracting.
FALSE
163. Endogenous opioids transmit impulses of pain.
FALSE
19. Somatic motor neurons innervate involuntary effectors.
FALSE
2. Glial cells normally lose their mitotic ability prior to birth.
FALSE
20. A nerve is a bundle of axons in the CNS.
FALSE
3. Both neurons and neuroglia will easily divide by mitosis.
FALSE
31. All axons in the PNS have a myelin sheath.
FALSE
32. Destruction of astrocytes would decrease the rate at which action potentials are transmitted.
FALSE
4. Most brain tumors in adults are found within neurons.
FALSE
49. The blood-brain barrier prevents hydrophobic molecules from diffusing into the brain.
FALSE
52. Excitable cells are incapable of maintaining a constant resting membrane potential.
FALSE
56. The average resting membrane potential of a neuron is -85mV.
FALSE
59. Nerve cells depolarize due to the influx of K+.
FALSE
67. During the absolute refractory period, a supramaximal stimulus can bring the cell to threshold.
FALSE
73. An inactivated ion channel will respond to a strong stimulus.
FALSE
76. Axons require ATP to produce an action potential.
FALSE
8. Anterograde transport uses dynein molecular motor proteins.
FALSE
83. The greater the number of depolarization regions on an axon, the faster the action potential will be conducted.
FALSE
88. Most synapses in the body are electrical.
FALSE
89. Electrical synapses are functionally linked by tight junctions.
FALSE
95. A lack of extracellular Ca2+ would cause increased release of neurotransmitters.
FALSE
106. An EPSP is conducted decrementally to the axon hillock, where voltage-gated Na+ and K+ channels are opened to created an action potential in the first segment of the axon.
TRUE
107. The nicotinic ACh receptor is a ligand-gated channel.
TRUE
108. An inhibitory postsynaptic potential would be produced by a neurotransmitter opening Cl- channels.
TRUE
125. Alzheimer's disease is associated with the loss of cholinergic fibers that end at the hippocampus and cerebral cortex.
TRUE
13. Retrograde axonal transport may be responsible for movement of herpes virus, rabies virus, and tetanus toxin from nerve terminals to the cell body.
TRUE
131. Serotonin is degraded in presynaptic neurons by monoamine oxidase.
TRUE
134. Serotonin is derived from the amino acid tryptophan and is an important neurotransmitter.
TRUE
136. Norepinephrine binding to a receptor stimulates the activity of adenylate cyclase.
TRUE
143. Parkinson's disease is associated with the loss of dopaminergic neurons.
TRUE
15. Most motor neurons are multipolar.
TRUE
153. Glycine and GABA stimulate opening of Cl- channels.
TRUE
160. CCK (cholecystokinin) may act as a neurotransmitter in the brain to promote feelings of satiety.
TRUE
164. Animals that cannot synthesize neuropeptide Y would be prone to seizures.
TRUE
176. ATP and adenosine can be released by nonneural cells to aid in blood clotting, taste, and pain.
TRUE
179. Both excitatory and inhibitory postsynaptic potentials undergo summation.
TRUE
188. Postsynaptic inhibition is caused by neurotransmitters that produce hyperpolarization.
TRUE
24. Schwann cells and oligodendrocytes have similar functions.
TRUE
33. Myelinated axons transmit action potentials more rapidly than unmyelinated axons.
TRUE
37. All axons in the PNS are surrounded by Schwann cells.
TRUE
47. Astrocytes can be excited by changes in intracellular Ca2+ concentration.
TRUE
51. The blood-brain barrier may prevent medications from reaching brain tissue.
TRUE
53. All cells have a membrane potential.
TRUE
54. Cells become more negative during hyperpolarization.
TRUE
6. Ganglia are clusters of nerve cell bodies located in the peripheral nervous system.
TRUE
66. Action potentials frequency encodes stimulus intensity.
TRUE
75. Both depolarization and repolarization are produced by the diffusion of ions down their concentation gradient.
TRUE
79. Conduction without decrement means that action potentials transmitted down an axon will not decrease in amplitude.
TRUE
81. Sensory neurons for muscle position are the fastest conducting neurons.
TRUE
93. Neurotransmitter release from synaptic vesicles is caused by Ca2+-synaptotagmin complex interruption of the SNARE complex.
TRUE
97. Neurotransmitter release can be inhibited by damaging the SNARE complex.
TRUE
