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1 | | The central nervous system (CNS) includes the brain and the cranial nerves. |
| | A) | True |
| | B) | False |
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2 | | The nervous system is composed of two principal types of cells - neurons and neuroglia. |
| | A) | True |
| | B) | False |
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3 | | After birth, the neurons do not undergo further division by mitosis, although some neurons can regenerate severed portions or sprout new branches under some conditions. |
| | A) | True |
| | B) | False |
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4 | | The Nissl bodies of the perikaryon contain densely staining areas of active mitochondria. |
| | A) | True |
| | B) | False |
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5 | | A mixed nerve contains both sensory and motor fibers. |
| | A) | True |
| | B) | False |
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6 | | The longer process of a neuron that conducts impulses away from the cell body is called a dendrite. |
| | A) | True |
| | B) | False |
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7 | | Orthograde (forward flow)and retrograde (reverse flow) transport in neurons is characteristic of the more rapid form of molecular movement in the neuron called axonal transport. |
| | A) | True |
| | B) | False |
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8 | | Association neurons (interneurons) are located entirely within the central nervous system. |
| | A) | True |
| | B) | False |
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9 | | Somatic motor neurons are responsible for both reflex and voluntary control of skeletal muscle. |
| | A) | True |
| | B) | False |
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10 | | The sheaths of Schwann surround all axons in the peripheral nervous system, but not in the central nervous system. |
| | A) | True |
| | B) | False |
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11 | | Gaps of exposed axon between the adjacent Schwann cells for the purpose of producing nerve impulses are called nodes of Ranvier. |
| | A) | True |
| | B) | False |
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12 | | Each Schwann cell can myelinate axons from many neurons. |
| | A) | True |
| | B) | False |
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13 | | Spaces (pores) are found between the endothelial cells lining the capillary wall in the brain. These pores help form the blood-brain barrier. |
| | A) | True |
| | B) | False |
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14 | | Myelin sheaths around the high number of axons in the CNS give this tissue a white color; so is called the white matter of the brain and spinal cord. |
| | A) | True |
| | B) | False |
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15 | | Unlike a Schwann cell, which forms a myelin sheath around only one axon, each oligodendrocyte has extensions like the tentacles of an octopus. |
| | A) | True |
| | B) | False |
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16 | | Experiments suggest that central nervous system axons may neuron nourishing" molecules are present. |
| | A) | True |
| | B) | False |
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17 | | Astrocytes have been shown to be important in the formation of synapses in the developing nervous system. |
| | A) | True |
| | B) | False |
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18 | | Bacterial infection of the brain would stimulate the actions of the microglial cells. |
| | A) | True |
| | B) | False |
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19 | | The tight junctions located between adjacent endothelial cells in brain capillaries that form the blood-brain barrier presents an obstacle to the use of polar drugs in the treatment of many brain diseases, such as Parkinson's disease. |
| | A) | True |
| | B) | False |
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20 | | Although all cells have a membrane potential, only muscle fibers, neurons, and a few other cell types are able to alter their membrane potential in response to stimulation. |
| | A) | True |
| | B) | False |
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21 | | The instrument that displays images of the upward and downward changes in the membrane potential on a cathode-ray fluorescent screen is called a voltmeter. |
| | A) | True |
| | B) | False |
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22 | | The return of the membrane potential toward the resting potential is called hyperpolarization. |
| | A) | True |
| | B) | False |
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23 | | When the inside of the cell becomes more negative due to the inward flow of negative charges, the membrane will be depolarized. |
| | A) | True |
| | B) | False |
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24 | | During depolarization, that potential at which the Na+ gates open causing a sudden and very rapid change in the membrane potential as Na+ ions diffuse down their concentration gradient, is known as the threshold potential. |
| | A) | True |
| | B) | False |
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25 | | During neuron stimulation, a fraction of a second after the Na+ gates open, they close again. Meanwhile, the resulting depolarization causes the K+ gates to open, allowing the efflux (outward flow) of K+. |
| | A) | True |
| | B) | False |
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26 | | A negative feedback loop is created as the rate of Na+ entry increases as the rate of membrane depolarization increases in an explosive fashion. |
| | A) | True |
| | B) | False |
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27 | | Since K+ is positively charged, the diffusion of K+ down its concentration gradient and out of the cell results in hyperpolarization. |
| | A) | True |
| | B) | False |
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28 | | A neuron poisoned with cyanide so that no ATP can be made will still produce action potentials for a period of time since active transport of ions is not directly involved in impulse conduction. |
| | A) | True |
| | B) | False |
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29 | | The amplitude (height) of an action potential is always the same, resulting in the "all-or-none" law of action potentials. |
| | A) | True |
| | B) | False |
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30 | | The greater the strength of the stimulus the greater the amplitude of action potentials; therefore the code for stimulus strength is amplitude modulated (AM), not frequency modulated (FM). |
| | A) | True |
| | B) | False |
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31 | | A low-intensity stimulus to a collection of axons (or a nerve) will only activate those few fibers in the group with lower thresholds, whereas a high-intensity stimulus can activate many more fibers including those with higher thresholds. |
| | A) | True |
| | B) | False |
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32 | | The absolute refractory period occurs before the relative refractory period. |
| | A) | True |
| | B) | False |
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33 | | The term cable properties of neurons refers to the ability of a neuron to transmit charges through its cytoplasm; a property that is quite poor due to the cell's high internal resistance. |
| | A) | True |
| | B) | False |
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34 | | Compared to metal wires, the axon is a very poor electrical conductor. |
| | A) | True |
| | B) | False |
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35 | | Every patch of membrane in an unmyelinated axon contains Na+ and K+ gates that must regenerate or remake a separate, completely new action potential that will move along the axon, usually in a direction away from the cell body. |
| | A) | True |
| | B) | False |
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36 | | The high-speed conduction of neural impulses is made possible due to the cable properties of the axon. |
| | A) | True |
| | B) | False |
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37 | | The action potential generated at the end of the axon looks different from that formed at the beginning of the axon. |
| | A) | True |
| | B) | False |
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38 | | Action potentials conducted along thicker, unmyelinated fibers are conducted faster than those along thin, unmyelinated fibers. |
| | A) | True |
| | B) | False |
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39 | | As opposed to thin, unmyelinated nerve fibers, thick myelinated fibers would be expected to mediate (to come in the middle of or to control) rapid responses of skeletal muscles. |
| | A) | True |
| | B) | False |
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40 | | Saltatory conduction of action potentials is made possible by the interruptions in the myelin sheath along axons, known as nodes of Ranvier. |
| | A) | True |
| | B) | False |
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41 | | A neuron-to-muscle synapse can also be called a myoneural and neuromuscular junction. |
| | A) | True |
| | B) | False |
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42 | | All synaptic transmission is electrical rather than chemical. |
| | A) | True |
| | B) | False |
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43 | | Acetylcholine, discovered by Otto Loewi, was one of the first neurotransmitter chemicals identified and is released from nerve endings to decrease heart rate. |
| | A) | True |
| | B) | False |
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44 | | Gap junctions are characteristic features of smooth and cardiac muscle cells (fibers), brain neurons, and even many embryonic tissues. |
| | A) | True |
| | B) | False |
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45 | | The term terminal boutons refers to the swollen ending of the presynaptic axon terminal. |
| | A) | True |
| | B) | False |
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46 | | Chemically-regulated channels are found in the postsynaptic membrane and open in response to binding of neurotransmitter molecules (ligands) to their postsynaptic receptor proteins. |
| | A) | True |
| | B) | False |
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47 | | Botulinum toxin contains enzymes that prevent the release of neurotransmitter molecules by cleaving and inactivating specific synapsin proteins that are required for exocytosis. |
| | A) | True |
| | B) | False |
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48 | | Depolarization of the postsynaptic membrane by specific neurotransmitter chemicals (ligands) results in an EPSP, whereas hyperpolarization of the postsynaptic membrane results in an IPSP. |
| | A) | True |
| | B) | False |
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49 | | At autonomic nerve endings, the effects of acetylcholine can be either excitatory or inhibitory, depending on the subtype of acetylcholine receptors present in that organ. |
| | A) | True |
| | B) | False |
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50 | | The two major subtypes of acetylcholine receptors are nicotinic and muscarinic, named after the particular toxin that bind and interact with each subtype of receptor. |
| | A) | True |
| | B) | False |
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51 | | Acetylcholie is transported into the postsynaptic cell cytoplasm, where it produces its effects, such as opening ion channels. |
| | A) | True |
| | B) | False |
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52 | | When neurotransmitters bind to the appropriate receptor on the postsynaptic cell the direct response is not an action potential, but rather ae graded potentials such as an EPSP or an IPSP. |
| | A) | True |
| | B) | False |
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53 | | Acetylcholinesterase is an enzyme found in the presynaptic cell that degrades acetylcholine. |
| | A) | True |
| | B) | False |
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54 | | The bond between the ligand, actylcholine and its receptor protein is relatively weak bond. |
| | A) | True |
| | B) | False |
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55 | | Unlike action potentials, excitatory postsynaptic potentials (EPSPs) have no threshold potential, can be summed, and have no refractory period. |
| | A) | True |
| | B) | False |
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56 | | Curare, a drug first used on poison darts by South American Indians, interrupts neuromuscular transmission at the synapse and thereby results in a spastic (causes muscles to spasm, or tighten) form of paralysis. |
| | A) | True |
| | B) | False |
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57 | | Exposure to nerve gas would lead to spastic paralysis. |
| | A) | True |
| | B) | False |
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58 | | Somatic motor neurons only make synapses with skeletal muscle fibers, resulting in postsynaptic depolarizations called end plate potentials. |
| | A) | True |
| | B) | False |
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59 | | The most common cause of senile dementia, Alzheimer's disease, is thought to be caused by a loss of CNS neurons that release the neurotransmitter called dopamine. |
| | A) | True |
| | B) | False |
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60 | | Some antidepressant drugs act to block the reuptake of serotonin. |
| | A) | True |
| | B) | False |
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61 | | Epinephrine is also known as adrenalin, a hormone secreted by the adrenal cortex. |
| | A) | True |
| | B) | False |
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62 | | As a neurotransmitter, norepinephrine binds to a G-coupled receptor. |
| | A) | True |
| | B) | False |
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63 | | Of the catecholamines, dopamine acts only as a neurotransmitter molecule and not as a hormone. |
| | A) | True |
| | B) | False |
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64 | | Drugs that inhibit the action of the enzymes that breakdown catecholamines, ultimately end up promoting the effects of monoamine neurotransmitter action on the postsynaptic membrane. |
| | A) | True |
| | B) | False |
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65 | | Instead of opening ionic channels directly in the postsynaptic membrane, monoamine neurotransmitters act through a second messenger molecule, such as cyclic adenosine monophosphate. |
| | A) | True |
| | B) | False |
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66 | | Schizophrenia may be caused, in part, by the mesolimbic dopaminergic pathways in the brain secreting too much dopamine or by the presence of increased numbers of D2 dopamine receptors in the forebrain. |
| | A) | True |
| | B) | False |
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67 | | Parasympathetic neurons of the peripheral nervous system use norepinephrine as the neurotransmitter at their synapses with smooth muscles, cardiac muscle, and glands. |
| | A) | True |
| | B) | False |
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68 | | Certain amino acids (such as glycine) act as excitatory neurotransmitters in the CNS by forming EPSPs, while others (such as glutamic acid) inhibit CNS neurons by producing IPSPs. |
| | A) | True |
| | B) | False |
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69 | | GABA (gamma-amino butyric acid) and glycine are excitatory neurotransmitters in the central nervous system, depolarizing the postsynaptic membrane and forming EPSPs. |
| | A) | True |
| | B) | False |
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70 | | Most inhibitory neurotransmitters act to hyperpolarize the postsynaptic membranes of their target cells, producing inhibitory postsynaptic potentials (IPSPs). |
| | A) | True |
| | B) | False |
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71 | | Animals poisoned with strychnine die from asphyxiation because their glycine receptor proteins are specifically blocked and they are unable to relax the diaphragm muscle (spastic paralysis). |
| | A) | True |
| | B) | False |
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72 | | Interestingly, many polypeptides that function as hormones secreted by the small intestine and other endocrine glands, can also be made and serve as neurotransmitters in the brain. |
| | A) | True |
| | B) | False |
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73 | | Synaptic plasticity is believed to be due in part to the release of neuromodulators and neurotransmitters from the same presynaptic cell. |
| | A) | True |
| | B) | False |
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74 | | Excessive release of glutamate may produce excitotoxicity. |
| | A) | True |
| | B) | False |
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75 | | The family of polypeptides produced by the brain and pituitary gland called opioids include β-endorphin, the enkephalins, and the neurotransmitter, dynorphin. |
| | A) | True |
| | B) | False |
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76 | | Spacial summation requires the actions of two synapses. |
| | A) | True |
| | B) | False |
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