Neuroscience Fundamentals: Exploring the Nervous System, Exams of Nursing

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NSCI 175 Exam 1 Study Questions

Why are a broad perspective and an interdisciplinary approach required for understanding the brain? Choose the correct option. A. Understanding the brain requires knowledge about many things, from the structure of the water molecule to the electrical and chemical properties of the brain. B. Understanding the brain is a focused area in natural science with the brain serving as the common point of focus. C. Understanding the brain requires the analysis of one approach at a time to yield a new synthesis. D. Understanding the brain requires the study of the different species of the brain. - Answer-A. Understanding the brain requires knowledge about many things, from the structure of the water molecule to the electrical and chemical properties of the brain. A neuroscientist investigates how different neural circuits in the brain analyze sensory information, form perceptions of the external world, make decisions, and execute movements. At what level of analysis is this research conducted? Choose the correct option. A. Cognitive neuroscience level B. Cellular neuroscience level C. Molecular neuroscience level D. Systems neuroscience level - Answer-D. Systems neuroscience level

At which level of analysis do neuroscientists study the different types of neurons and their functions? Choose the correct option. A. Cellular neuroscience B. Cognitive neuroscience C. Molecular neuroscience D. Behavioral neuroscience - Answer-A. Cellular neuroscience What is the rationale behind the use of animal models to understand the human brain? A. The nervous systems of different species of animals and humans share many common mechanisms. B. Brain mechanisms that motivate any reaction are identical in animal and human brains. C. Animal brains are identical to human brains but only smaller in size. D. Animal brains are easier to obtain than human brains. - Answer-A. The nervous systems of different species of animals and humans share many common mechanisms. What is the difference between replication and verification? A. Replication can only be done once whereas verification can be done many times. B. Replication and verification are not essentially different. C. Replication tests a hypothesis whereas verification rechecks the hypothesis. D. Replication is repeating the experiment in other subjects to rule out the possibility of chance. In verification, the experiment is repeated and the same observations are obtained by any scientist following the same protocol as the original observer. - Answer-D. Replication is repeating the experiment in other subjects to rule out the possibility of chance. In verification, the experiment is repeated and the same observations are obtained by any scientist following the same protocol as the original observer. An example of an observation in the scientific process would be (select all that apply): A. cutting nerve fibers to see what happens to movement B. repeating an experiment on a different group of patients

C. verifying an observation D. lesioning the hippocampus to see what happens to memory - Answer-A & D The Institutional Animal Care and Use Committee is formed by the animal rights representatives. A. True B. False - Answer-B. False Which of the following statements are true? Select all that apply. A.Living conditions of animals should be appropriate for their species and contribute to their health and comfort. B.Proper use of animals, including the avoidance or minimization of discomfort, distress, and pain when consistent with sound scientific practices, is imperative. C.Procedures involving animals should be designed and performed with due consideration of their relevance to human or animal health, the advancement of knowledge, or the good of society D.Investigators and other personnel do not need any training to conduct animal experiments. E.Animals selected for procedures should be of an appropriate species, quality, and the minimum number required to obtain valid results. - Answer-A, B, C, & E A scientist looks through a microscope at the structure of a neuron. The scientist notices a layer of molecules separating the neuron's intracellular space from the extracellular space. What is this part of the neuron known as? A. Soma B. Nuclear envelope C. Organelle D.

Neuronal membrane - Answer-D. Neuronal membrane What is the most important function of the rough endoplasmic reticulum? A. Site of protein synthesis B. Cellular respiration C. Post-translational protein processing D. RNA splicing - Answer-A. Site of protein synthesis What is a primary function of MAPs? A. Regulate the function and assembly of cytoskeleton B. Regulate the function and assembly of neurofilaments C. Regulate the function and assembly of microtubules D. Regulate the function and assembly of microfilaments - Answer-C. Regulate the function and assembly of microtubules The neuron doctrine stipulates that neurons A. are continuous with one another through a system of tubes. B. plus glial cells form functional units. C. are not continuous with one another. D. depend on one another for their metabolic needs. - Answer-C. are not continuous with one another. Some neurons have long axon that stretches from one part of the CNS to another. What are these called? A. local circuit neurons

B.

Interneurons C. projection neurons D. Motor neurons - Answer-C. projection neurons Primary sensory neurons: A. form connections only with other neurons B. command movement C. are the most abundant cells in the brain D. have neurites in the sensory sensory surfaces of the body - Answer-D. have neurites in the sensory sensory surfaces of the body What is the function of a neurotransmitter receptor in the dendritic membrane? A. Detect neurotransmitters B. Form gap junctions C. Destroy extra neurotransmitter left in the synaptic cleft D. Release synaptic vesicles - Answer-A. Detect neurotransmitters

Neurons can be classified based on: A. number of neurites B. nodes of Ranvier C. dendritic trees D. axon length E. gene expression - Answer-A, C, D & E "Spiny" and "aspinous" refers to a property of A. myelin B. axon length C. astrocytes D. dendrites - Answer-D. dendrites The major function of Schwann cells is the A. myelination of peripheral nerve fibers. B. myelination of axons in the brain.

C. scavenging of cellular debris. D. transmission of nutrients to neurons. - Answer-A. myelination of peripheral nerve fibers. The gaps between segments of myelin are known as A. nodes of Ranvier. B. cytoplasm. C. terminal boutons. D. synaptic clefts. - Answer-A. nodes of Ranvier. These cells are the most numerous cells in the brain. A. Pyramidal cells B. Astrocytes C. Stellate cells D. Microglia - Answer-B. Astrocytes A neuron without myelin would propagate nerve impulses: A. slowly B. quickly C. only under some conditions D. not at all - Answer-A. slowly

Which of the following are a function of microglia? A. Engulfing dead cells and debris B. Release acetylcholine C. Remodeling synaptic connections D. Both A and C - Answer-D. Both A and C The primary function of oligodendroglia is: A. myelinate neuron in the brain and spinal cord B. remove debris left by dead or degenerating brain cells C. regulate chemical content of extracellular space D. myelinate cells in the peripheral nervous system - Answer-A. myelinate neuron in the brain and spinal cord Which of these are functions of astrocytes? (select all that apply) A. astrocytes participate in synaptic pruning (removal of synapses) B.astrocytes bidirectionally signal with neurons, shaping synaptic transmission C. astrocytes play a role in synaptogenesis (the formation of new synapses) D. astrocytes express NG2 and can become neurons - Answer-B & C Some glial cells have neurotransmitter receptors.

A. True B. False - Answer-A. True What kind of cells can NG2 cells become? A. neurons B. oligodendrocytes C. microglia D. A & B - Answer-D. A & B What is the resting membrane potential? Choose the correct option. A. Positive charge inside the membrane with respect to outside at rest B. Generation and conduction of action potential at rest C. Difference in electrical charge across the membrane at rest D. Isolation of the cytosol from extracellular fluid - Answer-C. Difference in electrical charge across the membrane at rest Which of the following are the major charge carriers involved in the conduction of electricity in neurons? A. Proteins B. Ions C.

Cations D. Anions - Answer-B. Ions How do the lipids of the neuronal membrane contribute to the neuronal membrane potential? A. Catalyzes chemical reactions B. Encourages chemical interactions with water C. Integrates cytosol of neuron with extracellular fluid D. Forms a barrier to water-soluble ions and water - Answer-D. Forms a barrier to water-soluble ions and water Which force other than the ionic concentration gradient determines the equilibrium potential for an ion? A. Sodium potassium pump B. Selective ionic permeability C. Electrical resistance D. Electrical conductance - Answer-B. Selective ionic permeability How does the sodium potassium pump help maintain the resting membrane potential? A. Pumps sodium in and potassium out B. Uses calcium to pump sodium and potassium against their concentration gradients C. Pumps potassium in and sodium out D. Exchanges a sodium and a potassium for a calcium - Answer-C. Pumps potassium in and sodium out What is the meaning of an ion's equilibrium potential?

A. Difference in concentration between region with high ionic concentration and region with low ionic concentration B. Net movement of ions from a region of high concentration to a region of low concentration C. Difference between the real membrane potential and equilibrium potential for a particular ion D. Electrical potential difference that exactly balances an ionic concentration gradient - Answer-D. Electrical potential difference that exactly balances an ionic concentration gradient Which of the following factors determines the ion selectivity of specific ion channels? A. Number of ion channels in the membrane B. Nature of the groups lining the ion channel C. Number of protein molecules assembling to form a pore D. Gating properties - Answer-B. Nature of the groups lining the ion channel Distinguish between the head and tail of phospholipids. A. The phospholipids have a nonpolar head and polar tail. B. The phospholipids head contains hydrophilic phosphate and tail contains a hydrophobic hydrocarbon. C. The phospholipid head is hydrophobic and the hydrocarbon tail is hydrophilic. D. The phospholipid heads face each other and tails face the watery extracellular and intracellular environments. - Answer-B. The phospholipids head contains hydrophilic phosphate and tail contains a hydrophobic hydrocarbon. How are ion channels and ion pumps different? A. Ion channels are proteins and ion pumps are not B. Ion channels allow ions to passively diffuse across the cell membrane through their pores (when open) and ion pumps require energy (ATP) to actively transport ions across the cell membrane

C.

There are many types of ion channels, and only one type of ion pump D. Ion channels are always open and allow ions to constantly flow and ion pumps require energy (ATP) to open - Answer-B. Ion channels allow ions to passively diffuse across the cell membrane through their pores (when open) and ion pumps require energy (ATP) to actively transport ions across the cell membrane A simple reflex requires the nervous system to perform three functions. Two of these functions are to collect and distribute information. What is the third function? A. Process information B. Translate information C. Disintegrate information D. Integrate information - Answer-D. Integrate information Imagine a cell with a semi-permeable membrane that is selective to K+ ions only. The internal solution contains 100 mM KCl and the external solution contains 1 mM KCl. What equation would you use to determine the potential (EK) developed across the membrane? A. Goldman equation B. Ion equation C. Molarity equation D. Nernst equation - Answer-D. Nernst equation Imagine a cell with a semi-permeable membrane that is selective to K+ ions only. The internal solution contains 100 mM KCl and the external solution contains 1 mM KCl. What potential (EK) is developed across the membrane (round to the nearest whole number)? ______ mV - Answer--123mV Imagine a cell with a semi-permeable membrane that is selective to K+ ions only. The internal solution contains 100 mM KCl and the external solution contains 1 mM KCl. If 100 mM NaCl were added to the

inside of the cell, what would be the effect on the potential difference between the inside and outside of the cell? A. there would be no effect B. the cell would depolarize C. the cell would hyperpolarize - Answer-A. there would be no effect Imagine a cell with a semi-permeable membrane that is selective to Na+ ions only. The equilibrium potential for sodium (ENa) = 58 mV if the concentration of Na+ ions on the outside of the cell is 10 times the concentration of Na+ ions on the inside of the cell. What is the equilibrium potential (ENa) if the extracellular concentration of sodium ([Na]o) is increased by a factor of 10 (round to the nearest whole number)? ______ mV - Answer- Imagine a cell with a semi-permeable membrane that is selective to Na+ ions only. The equilibrium potential for sodium (ENa) = +58 mV if the concentration of Na+ ions on the outside of the cell is 10 times the concentration of Na+ ions on the inside of the cell. What is the equilibrium potential (ENa) if the extracellular concentration of sodium ([Na]o) is decreased by a factor of 10 (round to the nearest whole number)? ______ mV - Answer- Why is the resting membrane potential so much closer to EK than it is to ENa? A. at rest, PK > PNa B. at rest, EK is more negative than ENa is positive—you simply add them up to get the resting potential C. at rest, PNa > PK - Answer-A. at rest, PK > PNa What is meant by the action potential threshold? A. Critical level at which electrical current is injected through a microelectrode B. The action potential threshold is the same as the generator potential C. Critical level of hyperpolarization required to trigger an action potential D. Critical level of depolarization required to trigger an action potential - Answer-D. Critical level of depolarization required to trigger an action potential

What is the absolute refractory period? A. The period when the firing frequency is at about 1000 Hz. B. The period when the membrane potential stays hyperpolarized until the voltage-gated potassium channels close. C. The period when it is difficult to initiate another action potential for several milliseconds due to sodium channel inactivation. D. The time period that starts 1 ms after one action potential is initiated and ends when the next one is initiated. - Answer-A, B, C & D The movement of what ion is reflected in the rising phase of the action potential? A. Outward K+ B. Inward Na+ C. Outward Na+ D. Inward K+ - Answer-B. Inward Na+ What type of channel is affected by tetrodotoxin (TTX)? A. K+ channels are blocked by TTX. B. TTX blocks Cl- ion channels. C. TTX blocks the Na+ channel by binding tightly to a specific site on the outside of the channel.

D.

TTX sensitizes voltage-gated Na+ ion channels. - Answer-C. TTX blocks the Na+ channel by binding tightly to a specific site on the outside of the channel. How long does it take for a voltage-gated potassium channel to open? A. Voltage-gated potassium channels open when action potential fire at maximal frequency. B. Voltage-gated potassium channels take about 3 msec to open after depolarization. C. Voltage-gated potassium channels do not open immediately upon depolarization; they take about 1 msec to open after the membrane is depolarized. D. Voltage-gated potassium channels open as soon as the membrane is depolarized beyond threshold. - Answer-C. Voltage-gated potassium channels do not open immediately upon depolarization; they take about 1 msec to open after the membrane is depolarized. What property of the voltage-gated potassium channels allows K+ ions to pass? A. Depolarization causes the subunits to disintegrate so K+ ions can pass through the membrane. B. The voltage-gated potassium channels open when the polypeptide sub-units are disinhibited. C. Two polypeptide subunits are synthesized when the membrane is depolarized, allowing the K+ ions to pass. D. Depolarization causes the four polypeptide subunits specific to the voltage-gated K+ channel to twist into a shape that allows the K+ ions to pass. - Answer-D. Depolarization causes the four polypeptide subunits specific to the voltage-gated K+ channel to twist into a shape that allows the K+ ions to pass. The membrane potential closest to the equilibrium potential for sodium is _______ mV. A.

B.

C.

-

D.

+100 - Answer-B.

An afterpotential is A. a brief hyperpolarization that follows an EPSP (undershoot). B. a brief depolarization that follows an action potential (overshoot). C. a brief hyperpolarization that follows an action potential (undershoot). D. the portion of an action potential between 0 and +30 mV. - Answer-C. a brief hyperpolarization that follows an action potential (undershoot). What role do voltage-gated potassium channels play in the action potential? A. Voltage-gated potassium channels restore negative membrane potential after the spike. B. Voltage-gated potassium channels help depolarize the membrane toward the threshold for an action potential. C. Voltage-gated potassium channels interfere with sodium conductance. D. Voltage-gated potassium channels maintain the resting membrane potential. - Answer-A. Voltage- gated potassium channels restore negative membrane potential after the spike. How long does an action potential last from the beginning of the rising phase to the end of the falling phase? A. 2 milliseconds B. 2 seconds C. 2 microseconds D. 2 nanoseconds - Answer-A. 2 milliseconds

Which of the following are true? A. A neuron's physiology is determined by the number and type of ion channels it has. B. A neuron's physiology is determined by it's dendrites. C. Most pyramidal cells cannot sustain steady firing rates. D. All neurons show similar electrical behavior. - Answer-A & C Myelin increases the speed of conduction because it A. offers considerable resistance to the flow of current. B. releases special chemicals that aid conduction. C. increases capacitance. D. offers little resistance to the flow of ionic current. - Answer-A. offers considerable resistance to the flow of current. How does myelin help increase conduction velocity? A. It contains voltage-gated sodium channels. B. It provides electrical insulation. C. It makes the membrane more excitable. D. It increases axonal diameter. - Answer-B. It provides electrical insulation. Why do action potentials travel in only one direction? A. The membrane proteins are destroyed when an action potential fires and it takes time to replace them.

B. The membrane just behind the action potential is refractory due to inactivated sodium channels. C. The membrane just behind the action potential is refractory due to inactivated potassium channels. D. There is not enough sodium in the extracellular space after an action potential has just fired. - Answer-B. The membrane just behind the action potential is refractory due to inactivated sodium channels. Where is the spike-initiation zone in a typical neuron? A. The axon terminal B. The part of the neuron where the axon originates from the soma C. The cell body D. The part of the neuron where the dendrites originate from the soma - Answer-B. The part of the neuron where the axon originates from the soma The mode of action potential propagation along myelinated axons is called A. ranvierian. B. saltatory. C. hyperian. D. oligodendroid. - Answer-B. saltatory. Which of the following statements about multiple sclerosis (MS) is false? A. MS is characterized by increases in conduction velocity of the optic nerve. B. Symptoms of MS may include weakness, lack of coordination, impaired vision and speech.

C. Magnetic resonance imaging can help diagnose some cases of MS. D. MS is characterized by demyelination of axons along with some axon loss. - Answer-A. MS is characterized by increases in conduction velocity of the optic nerve. In many sensory neurons, the spike-initiation zone A. is located at the axon hillock. B. contains few voltage-gated sodium channels. C. isn't necessary. D. is near the sensory nerve endings. - Answer-D. is near the sensory nerve endings. Lidocaine A. is the most widely used anesthetic B. increases depolarization of the nerve C.works more quickly at active nerves where sodium channels are frequently opening D. block sodium channels on the extracellular side - Answer-A & C What types of cells can a neuron communicate with at a synapse? A. Muscle cell B. Glandular cell C. Another neuron D. Another neuron; Muscle cell; Glandular cell - Answer-D. Another neuron; Muscle cell; Glandular cell What is a gap junction? A. Electrical synapse B. Chemical synapse C. Synapse between a neuron and a muscle cell

D. Synapse between a neuron and a glandular cell - Answer-A. Electrical synapse What is the other name for dense-core vesicles? Choose the correct option. A. Presynaptic element B. Synaptic cleft C. Synaptic vesicles D. Secretory granules - Answer-D. Secretory granules Why are neuromuscular junctions such reliable synapses? A. Because the motor end-plate contains a series of shallow folds B. Because the presynaptic terminal contains a large number of active zones C. Because the axon terminal is so large D. Because the axon terminal is so large; the presynaptic terminal contains a large number of active zones and the motor end-plate contains a series of shallow folds - Answer-D. Because the axon terminal is so large; the presynaptic terminal contains a large number of active zones and the motor end-plate contains a series of shallow folds What are vesicular transporters? What is their role? A. Special proteins embedded in the vesicle membrane; responsible for concentrating neurotransmitters inside the vesicle B. Special proteins embedded in the vesicle membrane; responsible for synthesizing neurotransmitters C. Synthesizing enzymes for both amino acid and amine neurotransmitters; responsible for concentrating neurotransmitters inside the vesicle D.

Enzymes that synthesize neurotransmitters from metabolic precursors; responsible for concentrating neurotransmitters in the synaptic cleft - Answer-A. Special proteins embedded in the vesicle membrane; responsible for concentrating neurotransmitters inside the vesicle Which of the following channels in the active zones of the synaptic terminal open when the membrane depolarizes and causes the release of synaptic vesicles? A. Sodium channels B. Potassium channels C. Voltage-gated sodium channels D. Voltage-gated calcium channels - Answer-D. Voltage-gated calcium channels Under what conditions are peptide neurotransmitters released from the synaptic terminal? A. Every action potential B. Only with high-frequency trains of action potentials C. Only in 1 in 100 action potentials D. Only with low-frequency trains of action potentials - Answer-B. Only with high-frequency trains of action potentials What are second messengers? A. Voltage-gated ion channels B. Special proteins that span a 3-nm gap between two cell membranes C. Peptide neurotransmitters D. Molecules that activate additional enzymes in the cytosol - Answer-D. Molecules that activate additional enzymes in the cytosol What do we mean when we describe synaptic transmission as quantal?

A. Each vesicle contains approximately the same amount of neurotransmitter (a quanta), so when we examine post-synaptic responses they should all be a multiple of the response to one quanta B. We're just trying to make it sound sciencey C. Each vesicle contains a different amount of neurotransmitter and how much neurotransmitter released from a single vesicle varies--this variation is called quantal - Answer-A. Each vesicle contains approximately the same amount of neurotransmitter (a quanta), so when we examine post-synaptic responses they should all be a multiple of the response to one quanta What is synaptic integration? A. Adding together all IPSPs generated by a single neuron B. A method of comparing the amplitudes of miniature postsynaptic potentials C. Adding together all EPSPs generated by a single neuron D. A process by which multiple synaptic potentials combine within one postsynaptic neuron - Answer- D. A process by which multiple synaptic potentials combine within one postsynaptic neuron Most IPSPs are attributable to the A. opening of sodium channels. B. closing of potassium channels. C. None of these. D. opening of chloride channels. - Answer-D. opening of chloride channels. Inhibitory postsynaptic potentials differ from excitatory postsynaptic potentials most significantly in their A. ease of elicitation. B. direction of membrane polarization. C. overall amplitude. D. degree of capacitance. - Answer-B. direction of membrane polarization.

Miniature postsynaptic potentials are produced A. by the smallest axons. B. in response to weak stimuli. C. by the smallest neurotransmitters. D. by spontaneous release of neurotransmitter. - Answer-D. by spontaneous release of neurotransmitter. Which of the following statements about EPSPs in the central nervous system is false? A. A single EPSP can generate an action potential. B. Multiple EPSPs arriving together at different locations on the dendritic tree can summate and help bring a neuron to threshold. C. EPSPs occurring close together in time can summate and help bring a neuron to threshold. D. Their effect in the central nervous system can be nullified by IPSPs. - Answer-A. A single EPSP can generate an action potential. Which of the following statements about length constant are false? A. The length constant is only applicable to dendrites B. The length constant is an index of how far depolarization can spread down a dendrite or axon. C. The length constant depends on internal resistance. D. The length constant depends on membrane resistance. - Answer-A. The length constant is only applicable to dendrites Modulation of synaptic transmission

A. works through activation of g-protein-coupled receptors B. always generates an action potential C. has no effect synaptic integration D. works through activation of ion-gated channels - Answer-A. works through activation of g-protein- coupled receptors Whether or not an EPSP contributes to the action potential depends on: A. the distance the synapse is from the axon hillock B. the number of coactive excitatory synapses C. the properties of the dendritic membrane D. inhibitory synapses - Answer-A, B, C & D Membrane resistance A. represents the resistance to current flowing within the axon or dendrite B. represents the resistance to current flowing across the membrane C. has been made up to torture you D. depends on the number of closed ion channels - Answer-B. represents the resistance to current flowing across the membrane Acetylcholine (ACh) is the main transmitter used at mammalian A. cerebral cortical synapses. B. neuromuscular junctions.

C. spinal cord synapses. D. visual system synapses. - Answer-B. neuromuscular junctions. The cholinergic drug atropine _______ receptors. A. blocks nicotinic B. activates nicotinic C. blocks muscarinic D. activates muscarinic - Answer-C. blocks muscarinic The NMDA receptor is a type of receptor for the neurotransmitter A. glutamate B. acetylcholine. C. dopamine. D. GABA. - Answer-A. glutamate In the mammalian brain, the major inhibitory neurotransmitter is A. GABA. B. glycine. C. serotonin. D. acetylcholine. - Answer-A. GABA. What is microionophoresis? A. Movement of ions over extremely small distances B. Method of applying small amounts of neurotransmitter candidates to the surface of neurons C. Method of miniaturizing the brain for more efficient study