Exam 1 Quizzes
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. Organelle B. Neuronal membrane C. Nuclear envelope D. Soma
B
An afterpotential is A. a brief hyperpolarization that follows an EPSP (undershoot). B. a brief hyperpolarization that follows an action potential (undershoot). C. the portion of an action potential between 0 and +30 mV. D. a brief depolarization that follows an action potential (overshoot).
B
An agonist A. only works on GABA receptors B. mimics the effects of a neurotransmitter C. breaks down acteylcholine D. blocks the effects of a neurotransmitter
B
In the mammalian brain, the major inhibitory neurotransmitter is A. serotonin. B. GABA. C. acetylcholine. D. glycine.
B
Inhibitory postsynaptic potentials differ from excitatory postsynaptic potentials most significantly in their A. ease of elicitation. B. direction of membrane polarization. C. degree of capacitance. D. overall amplitude.
B
Membrane resistance _____ A. represents the resistance to current flowing down the dendrite B. represents the resistance to current flowing across the membrane
B
Primary sensory neurons: A. form connections only with other neurons B. have neurites in the sensory surfaces of the body C. command movement D. are the most abundant cells in the brain
B
The NMDA receptor is a type of receptor for the neurotransmitter A. acetylcholine. B. glutamate. C. GABA. D. dopamine.
B
We now understand that most differences between neurons ultimately can be explained by differences in gene expression A. False B. True
B
What is the absolute refractory period? A. The period when the firing frequency is at about 1000 Hz. B. The time period of 1 msec after one action potential is initiated and before the next one is initiated. C. The period when the membrane potential stays hyperpolarized until the voltage-gated potassium channels close.
B
What is the function of a neurotransmitter receptor in the dendritic membrane? A. Destroy extra neurotransmitter left in the synaptic cleft B. Detect neurotransmitters C. Release synaptic vesicles D. Form gap junctions
B
What is the rationale behind the use of animal models to understand the human brain? A. Animal brains are easier to obtain than human brains. B. The nervous systems of different species of animals and humans share many common mechanisms. C. Animal brains are identical to human brains but only smaller in size. D. Brain mechanisms that motivate any reaction are identical in animal and human brains.
B
What property of amino-acid gated channels determines the duration of a neurotransmitter's effect? A. The pharmacology of the binding site B. The kinetics of the binding process C. The selectivity of the ion channels D. The conductance of the open channels
B
When an equilibrium state is reached, which of the following is true? A. The electrical force is greater than the diffusional force. B. The the diffusional and electrical forces are equal. C. All ion channels are closed. D. The membrane potential is 0mV.
B
Where is the spike-initiation zone in a typical neuron? A. The cell body B. The part of the neuron where the axon originates from the soma C. The axon terminal D. The part of the neuron where the dendrites originate from the soma
B
Which cells are involved in neurogenesis and also serve as scaffolds for the migration of newly generated neurons? A. ependymal cells B. radial glia cells C. microglia D. Satellite cells
B
Which equation can be used to calculate the equilibrium potential for an ion? A. The Goldman Equation B. Nernst Equation
B
Which of the following factors determines the ion selectivity of specific ion channels? A. Number of protein molecules assembling to form a pore B. Nature of the groups lining the ion channel C. Number of ion channels in the membrane D. Gating properties
B
Which of the following statements about length constant are false? A. The length constant depends on membrane resistance. B. The length constant is an index of how far hyperpolarization spread down a dendrite or axon. C. The length constant depends on internal resistance. D. The length constant is an index of how far depolarization spread down a dendrite or axon.
B
Which of the following statements about multiple sclerosis (MS) is false? A. Symptoms of MS may include weakness, lack of coordination, impaired vision and speech. B. MS is characterized by increases in conduction velocity of the optic nerve. C. Magnetic resonance imaging can help diagnose some cases of MS. D. MS is characterized by demyelination of axons along with some axon loss.
B
Why do action potentials travel in only one direction? A. There is not enough sodium in the extracellular space after an action potential has just fired. 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. The membrane proteins are destroyed when an action potential fires and it takes time to replace them.
B
In a metabotropic receptor, the g-protein receptor is on the ___ side of the membrane, and the transmitting binding site is on the ___ side of the membrane. A. extracellular; intracellular B. intracellular; intracellular C. intracellular; extracellular D. extracellular; extracellular
C
Miniature postsynaptic potentials are produced A. in response to weak stimuli. B. by the smallest neurotransmitters. C. by spontaneous release of neurotransmitter. D. by the smallest axons.
C
Myelin increases the speed of conduction because it A. releases special chemicals that aid conduction. B. increases capacitance. C. offers considerable resistance to the flow of current across the membrane. D. offers little resistance to the flow of ionic current across the membrane.
C
One advantage of G-protein coupled receptors is A. fast response B. simple process C. signal amplification
C
The major function of Schwann cells is the A. myelination of axons in the brain. B. scavenging of cellular debris. C. myelination of peripheral nerve fibers. D. transmission of nutrients to neurons.
C
What are second messengers? A. Special proteins that span a 3-nm gap between two cell membranes B. Peptide neurotransmitters C. Molecules that activate additional enzymes in the cytosol D. Voltage-gated ion channels
C
What is a gap junction? A. Synapse between a neuron and a glandular cell B. Synapse between a neuron and a muscle cell C. Electrical synapse D. Chemical synapse
C
What is a primary function of MAPs? A. Regulate the function and assembly of microfilaments B. Regulate the function and assembly of neurofilaments C. Regulate the function and assembly of microtubules D. Regulate the function and assembly of cytoskeleton
C
What is microionophoresis? A. Movement of ions over extremely small distances B. Method of miniaturizing the brain for more efficient study C. Method of applying small amounts of neurotransmitter candidates to the surface of neurons D. Method of removing small amounts of neurotransmitter from the synaptic terminal
C
The Institutional Animal Care and Use Committee is formed by the animal rights representatives. True or False
False
What is the meaning of an ion's equilibrium potential? A. Difference between the real membrane potential and equilibrium potential for a particular ion B. Difference in concentration between region with high ionic concentration and region with low ionic concentration C. Electrical potential difference that exactly balances an ionic concentration gradient D. Net movement of ions from a region of high concentration to a region of low concentration
C
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
D
Acetylcholine (Ach) is the main transmitter used at mammalian A. cerebral cortical synapses. B. spinal cord synapses. C. visual system synapses. D. neuromuscular junctions.
D
Dendrites do not generate action potential because A. they have too many potassium channels. B. they are not myelinated. C. there are too many of them. D. they have few voltage-gated sodium channels.
D
How do the lipids of the neuronal membrane contribute to the neuronal membrane potential? A. Integrates cytosol of neuron with extracellular fluid B. Catalyzes chemical reactions C. Encourages chemical interactions with water D. Forms a barrier to water-soluble ions and water
D
How does myelin help increase conduction velocity? A. It makes the membrane more excitable. B. It increases axonal diameter. C. It contains voltage-gated sodium channels. D. It provides electrical insulation
D
How long does an action potential last from the beginning of the rising phase to the end of the falling phase? A. 2 seconds B. 2 microseconds C. 2 nanoseconds D. 2 milliseconds
D
In many sensory neurons, the spike-initiation zone A. is located at the axon hillock. B. isn't necessary. C. contains few voltage-gated sodium channels. D. is near the sensory nerve endings.
D
Most IPSPs are attributable to the A. None of these. B. opening of sodium channels. C. closing of potassium channels. D. opening of chloride channels.
D
The equilibrium potential for sodium is about _______ mV. A. -42 B. -80 C. +100 D. +62
D
The gaps between segments of myelin are known as A. terminal boutons. B. synaptic clefts. C. cytoplasm. D. nodes of Ranvier.
D
The mode of action potential propagation along myelinated axons is called A. ranvierian. B. oligodendroid. C. hyperian. D. saltatory.
D
The movement of what ion is reflected in the rising phase of the action potential? A. Inward K+ B. Outward K+ C. Outward Na+ D. Inward Na+
D
The neuron doctrine stipulates that neurons A. plus glial cells form functional units. B. depend on one another for their metabolic needs. C. are continuous with one another through a system of tubes. D. are not continuous with one another.
D
The relative ability of an electrical charge to migrate from one point to another is the ___ A. Electrical potential B. Electrical equilibrium C. Electrical voltage D. Electrical conductance
D
Under what conditions are peptide neurotransmitters released from the synaptic terminal? A. Only with low-frequency trains of action potentials B. Only in 1 in 100 action potentials C. Every action potential D. Only with high-frequency trains of action potentials
D
What is synaptic integration? A. A process by which multiple synaptic potentials combine within one postsynaptic neuron B. A method of comparing the amplitudes of miniature postsynaptic potentials C. Adding together all IPSPs generated by a single neuron D. Adding together all EPSPs generated by a single neuron
A
A neuron without myelin would propagate nerve impulses: A. quickly B. slowly
B
"Spiny" and "aspinous" refers to a property of A. dendrites B. myelin C. astrocytes D. axon length
A
ACh binds to the __ subunits on a nicotinic ACh receptor. A. alpha B. beta C. gamma D. delta
A
An argument against using computer models rather than animal models is: A. you must understand what you are modeling before you can make a good model B. computers aren't that useful in neuroscience research C. computer models are outdated D. All of these are good arguments against using computer models
A
How does the sodium potassium pump help maintain the resting membrane potential? A. Pumps potassium in and sodium out B. Pumps sodium in and potassium out C. Uses calcium to pump sodium and potassium against their concentration gradients D. Exchanges a sodium and a potassium for a calcium
A
If the extracellular concentration of K+ increased, what would happen to the neuron's membrane potential? A. Depolarization B. Hyperpolarization C. Nothing
A
Some neurons have long axon that stretches from one part of the CNS to another. What are these called? A. Golgi type I neurons B. Motor neurons C. Golgi type II neurons D. Interneurons
A
Some neurons have short axons that do not extend beyond the vicinity of the cell body. What are these called? Choose the correct option. A. Golgi type II neurons B. Golgi type I neurons
A
The cholinergic drug atropine _______ receptors. A. blocks muscarinic B. activates muscarinic C. activates nicotinic D. blocks nicotinic
A
The primary function of oligodendroglia is: A. myelinate neuron in the brain and spinal cord B. myelinate cells in the peripheral nervous system C. regulate chemical content of extracellular space D. remove debris left by dead or degenerating brain cells
A
The process that couples a neurotransmitter to activation of a downstream enzyme is referred to as ___ A. second messenger cascade B. apoptosis C. the downstream hypothesis D. protein-coupling
A
These cells are the most numerous cells in the brain. A. Astrocytes B. Pyramidal cells C. Microglia D. Stellate cells
A
What indicates an equilibrium state has been reached? A. The net flow of K+ ions across the membrane ceases. B. The net flow of Cl- ions across the membrane ceases. C. The membrane potential is at exactly -80mV. D. The membrane potential is at exactly -64mV.
A
What is the difference between replication and verification? A. 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. B. Replication tests a hypothesis whereas verification rechecks the hypothesis. C. Replication can only be done once whereas verification can be done many times. D. Replication and verification are not essentially different.
A
What is the other name for dense-core vesicles? Choose the correct option. A. Secretory granules B. Synaptic cleft C. Synaptic vesicles D. Presynaptic element
A
What type of channel is affected by tetrodotoxin (TTX)? A. TTX blocks the Na+ channel by binding tightly to a specific sight on the outside of the channel. B. TTX sensitizes voltage-gated Na+ ion channels. C. TTX blocks Cl- ion channels. D. K+ channels are blocked by TTX.
A
What types of cells can a neuron communicate with at a synapse? A. Another neuron; Muscle cell; Glandular cell B. Glandular cell C. Muscle cell D. Another neuron
A
Which of the following is the major charge carriers involved in the conduction of electricity in neurons? A. Ions B. Proteins
A
Why are neuromuscular junctions such reliable synapses? A. All of these are reasons! B. Because the presynaptic terminal contains a large number of active zones C. Because the axon terminal is so large D. Because the motor end-plate contains a series of shallow folds
A
Convergence of effects can take place at the level of the A. G-protein B. second messenger cascade C. type of ion channel D. None of these
A,B,C
Whether or not an EPSP contributes to the action potential depends on: A. the properties of the dendritic membrane B. the number of coactive excitatory synapses C. the distance the synapse is from the axon hillock D. inhibitory synapses
A,B,C,D
Which of the following statements are true about transporters? Select all that apply. A. They are the molecular site at which many psychoactive drugs work B. They shuttle transmitter from extracellular fluid to the presynaptic terminal C. They are large proteins that span cell membranes D. They only transport glutamate E. They pack transmitter into synaptic vesicles
A,B,C,E
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. 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 C. Investigators and other personnel do not need any training to conduct animal experiments. D. Proper use of animals, including the avoidance or minimization of discomfort, distress, and pain when consistent with sound scientific practices, is imperative. E. Animals selected for procedures should be of an appropriate species, quality, and the minimum number required to obtain valid results.
A,B,D,E
Neurons can be classified based on (select all that apply): A. axon length B. nodes of Ranvier C. dendritic trees D. number of neurites
A,C,D
An example of an observation in the scientific process would be (select all that apply): A. verifying an observation B. lesioning the hippocampus to see what happens to memory C. cutting nerve fibers to see what happens to movement D. repeating an experiment on a different group of patients
B and C
The following are characterized by progressive degeneration of specific neurons in the brain (Select all that apply): A. Autism B. Alzheimer's disease C. Parkinson's disease D. Epilepsy
B and C
Select the differences between AMPA and NMDA receptors. A. Glutamate binds to AMPA but not to NMDA. B. NMDA receptors are permeable to calcium, but AMPA receptors are not C. AMPA receptors are permeable to calcium, but NMDA receptors are not D. NMDA receptors are both voltage and ion gated, whereas AMPA receptors are only ion gated.
B,D
At rest, which of the following is true about ion concentrations? A. K+ and Na+ are more concentrated on the inside; Cl- is more concentrated on the outside. B. K+ is more concentrated on the outside; Na+ and Cl- are more concentrated on the inside. C. K+ is more concentrated on the inside; Na+ and Cl- are more concentrated on the outside. D. Na+ is more concentrated on the inside; K+ and Cl- are more concentrated on the outside.
C
Distinguish between the head and tail of phospholipids. A. The phospholipid heads face each other and tails face the watery extracellular and intracellular environments. B. The phospholipid head is hydrophobic and the hydrocarbon tail is hydrophilic. C. The phospholipids head contains hydrophilic phosphate and tail contains a hydrophobic hydrocarbon. D. The phospholipids have a nonpolar head and polar tail.
C
How do action potentials differ from passively conducted electrical signals? A. Action potentials diminish over distance; passively conducted signals do not diminish over distance B. Action potentials are transmitted over short distances; passively conducted signals are conducted over long distances C. Action potentials are signals of fixed size and duration; passively conducted signals are not signals of fixed size and duration D. Action potentials occur only in nerve cells; passively conducted signals occur only in muscle cells
C
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 open as soon as the membrane is depolarized beyond threshold. C. Voltage-gated potassium channels do not open immediately upon depolarization; they take about 1 msec to open after the membrane is depolarized.
C
What property of the voltage-gated potassium channels allows K+ ions to pass? A. The voltage-gated potassium channels open when the polypeptide sub-units are disinhibited. B. Depolarization causes the subunits to disintegrate so K+ ions can pass through the membrane. C. 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. D. Two polypeptide subunits are synthesized when the membrane is depolarized, allowing the K+ ions to pass.
C
What role do voltage-gated potassium channels play in the action potential? A. Voltage-gated potassium channels interfere with sodium conductance. B. Voltage-gated potassium channels help depolarize the membrane toward the threshold for an action potential. C. Voltage-gated potassium channels restore negative membrane potential after the spike. D. Voltage-gated potassium channels maintain the resting membrane potential.
C
Which of the following are a function of microglia? A. Myelination of neurons B. Release acetylcholine C. Remodeling synaptic connections D. Both A and C
C
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. Potassium channels B. Voltage-gated sodium channels C. Voltage-gated calcium channels D. Sodium channels
C
Which of the following is not a catecholamine neurotransmitter? A. Norepinephrine B. Epinephrine C. Serotonin D. Dopamine
C
What are vesicular transporters? What is their role? A. Special proteins embedded in the vesicle membrane; responsible for synthesizing neurotransmitters B. Enzymes that synthesize neurotransmitters from metabolic precursors; responsible for concentrating neurotransmitters in the synaptic cleft C. Synthesizing enzymes for both amino acid and amine neurotransmitters; responsible for concentrating neurotransmitters inside the vesicle D. Special proteins embedded in the vesicle membrane; responsible for concentrating neurotransmitters inside the vesicle
D
What is meant by the action potential threshold? A. Critical level of hyperpolarization required to trigger an action potential B. The action potential threshold is the same as the generator potential C. Critical level at which electrical current is injected through a microelectrode D. Critical level of depolarization required to trigger an action potential
D
What is resting membrane potential? Choose the correct option. A. Isolation of the cytosol from extracellular fluid B. Generation and conduction of action potential at rest C. Positive charge inside the membrane with respect to outside at rest D. Difference in electrical charge across the membrane at rest
D
What is the most important function of the rough endoplasmic reticulum? A. RNA splicing B. Cellular respiration C. ATP production D. Site of protein synthesis
D
Which of the following statements about EPSPs in the central nervous system is false? A. EPSPs occurring close together in time can summate and help bring a neuron to threshold. B. Their effect in the central nervous system can be nullified by IPSPs. C. Multiple EPSPs arriving together at different locations on the dendritic tree can summate and help bring a neuron to threshold. D. EPSPs are often caused by the influx of Cl- into the neuron
D
A neurotransmitter only has one effect. True or False
False
GABA and glycine receptors gate a Cl- channel. True or False
True
A membrane at rest is sensitive to changes in extracellular potassium. True or False
True
