Exam 6
Color blindness is caused by heritable mutations in cone photoreceptors. How many cone types does the retina of a colorblind individual typically contain? A. only one B. two C. three D. four E. five
2222222222222
What diffuses across the narrow synaptic cleft between the presynaptic axon and the postsynaptic cell to transmit a nerve impulse? A.neurotransmitter B.electrical impulse C.Na+ ion D.vesicle E. action potential
A.neurotransmitter
A typical AA battery has a potential of 1.5V. One can think of the potential in a neuron as having similarities to that of a battery. How does the resting potential of a typical neuron compare to that of a 1.5V AA alkaline battery? A. A typical neuron has a resting potential of -70mV, or about 5% the voltage of the battery. B.A typical neuron has a resting potential of -70V, or about 50x the voltage of the battery. C.A typical neuron has a resting potential of +70mV, or about 5% the voltage of the battery. D.A typical neuron has a resting potential of +70V, or about 50x the voltage of the battery.
A. A typical neuron has a resting potential of -70mV, or about 5% the voltage of the battery.
Charcot-Marie-Tooth is the most commonly inherited peripheral neuropathy, and has no known cure. Patients suffer damage to motor and sensory neurons, leading to degeneration of muscles and gradual loss of motor control. Mutation of the peripheral myelin protein 22 (PMP22) gene, which causes demyelination of peripheral neurons, is a more common cause of Charcot-Marie-Tooth disease. In which cells is the function of the PMP22 gene important for normal function? A. Schwann cells B. fibroblasts C. peripheral neurons D. oligodendrocytes E. astrocytes
A. Schwann cells
All sensory input arrives at the central nervous system in the same form, as ____________ propagated by afferent neurons. Perception of the type and intensity of a stimulus depends on which part of the brain the impulse projects to and the firing frequency of the sensory neuron. A. action potentials B. receptor potentials C. reflexes D. frequency localizations E. thresholds
A. action potentials
Charcot-Marie-Tooth is the most commonly inherited peripheral neuropathy, and has no known cure. Patients suffer damage to motor and sensory neurons, leading to degeneration of muscles and gradual loss of motor control. Genetic studies have found that Charcot-Marie-Tooth may be caused by a mutation in the gene Mitofusin-2 (MFN2), which causes mitochondria to form large clumps. In what area of a neuron are these clumps most likely to cause a problem? A. axon B. synapse C. soma D. dendrite E. myelin
A. axon
What is the elongated extension of a neuron that nerve impulses travel along? A. axon B.cell body C. dendrite D. oligodendrocyte E. synapse
A. axon
When membrane proteins on an olfactory neuron are stimulated by the binding of a specific chemical, what is the immediate result? A. membrane depolarization B. membrane repolarization C. active ion transport D. membrane E.hyperpolarization F.neurotransmitter release
A. membrane depolarization
Charcot-Marie-Tooth is the most commonly inherited peripheral neuropathy, and has no known cure. Patients suffer damage to motor and sensory neurons, leading to degeneration of muscles and gradual loss of motor control. In Charcot-Marie-Tooth neuropathy, both sensory and motor neurons are damaged. What do these two sets of neurons comprise? A. peripheral nervous system B.autonomic nervous system C.somatic nervous system D.parasympathetic nervous system E.central nervous system
A. peripheral nervous system
Botulinum toxin-- A toxin produced by the bacterium Clostridium botulinum. Known for sometimes lethal poisoning from infected meat products. In modern controlled medical or cosmetic use, the very same toxin is known as Botox. Tetanus toxin-- Another very potent neurotoxin produced by Clostridium tetani. Strichnine-- A highly poisonous alkaloid produced by the Strychnos nux-vomica tree, historically used to kill rats and other pests. In contrast to these toxins, strichnine acts postsynaptically, to block glycine from binding to receptors on motor neurons. Would you expect the symptoms of strichnine poisoning to be more similar to those of botulinum or tetanus toxin? A. tetanus toxin B. botulinum
A. tetanus toxin
Which ion channel is primarily responsible for the action potential? A. the voltage-gated sodium channel B. the voltage-gated potassium channel C. the ligand-gated sodium channel D. the ligand-gated potassium channel E. the non-gated sodium channel
A. the voltage-gated sodium channel
What does the middle ear consist of? A. three ossicle bones B. the ear canal C. the ear drum D. the vestibular canal E. the tympanic canal
A. three ossicle bones
Is the resting membrane potential of a neuron closer to the equilibrium potential for K+ or Na+? A.K+ B.Na+ C.It is an average of the two.
A.K+
Sodium ions are single atoms. Why can't they simply diffuse through the cell membrane's lipid bilayer? A.Since they are charged, ions can't cross the hydrophobic center of the membrane without a channel or pump. B.Sodium ions are covalently attached in groups of three, which are too large to diffuse easily. C. Ions do traverse the membrane easily, but the sodium-potassium pump moves them back across. D.Chelator proteins capture any ions that start to cross the bilayer.
A.Since they are charged, ions can't cross the hydrophobic center of the membrane without a channel or pump.
Which neurotransmitter is released from a motor neuron at the neuromuscular junction? A.acetylcholine B.GABA C.ephinephrine D.dopamine E.serotonin
A.acetylcholine
A typical AA battery has a potential of 1.5V. One can think of the potential in a neuron as having similarities to that of a battery. If you were to compare the resting potential of a neuron to a battery, which way is the battery oriented? A.positive terminal outside of the cell, and negative terminal inside B.positive terminal inside of the cell, and negative terminal outside C.positive terminal pointing toward the axon, negative terminal toward the dendrite D.positive terminal pointing toward the dendrite, negative terminal toward the axon E.both terminals inside the cell soma
A.positive terminal outside of the cell, and negative terminal inside
Which of the following targets is NOT regulated by the autonomic nervous system? A.skeletal muscles B.cardiac muscles C.glands of the body D. smooth muscles E. none of these
A.skeletal muscles
Nerve impulses are electrical signals produced by which structure? A.lipid sheath of Schwann cell B plasma membrane of neuron C.synapse Dneuromuscular junction
B plasma membrane of neuron
Which diagram correctly illustrates the distribution of ions in a resting neuron? (Note: A larger symbol indicates a higher concentration of that ion.) A.A B. B C. C D. D
B. B
What does the Nernst equation allow us to do? A. Predict the function of a specific type of neuron. B. Calculate the equilibrium potential for an ion. C. Use a computer program to model axonal transmission. D. Calculate the magnitude of depolarization during an action potential.
B. Calculate the equilibrium potential for an ion.
At myelinated areas of the axon (i.e. between nodes of Ranvier), which of the following statements is true? A. There is an increased number of voltage-gated sodium channels. B. There is increased resistance across the membrane. C.There is increased capacitance across the membrane. D.There is increased transport of potassium across the membrane.
B. There is increased resistance across the membrane.
What are the short retinal photoreceptors responsible for color vision called? A. rods B. cones C. bipolar cells D. glial cells E. ganglion cells
B. cones
What is the photopigment in rod cells called? A. photopsin B. rhodopsin C. opsin D. carotene E. melanin
B. rhodopsin
Three-quarters of the substantial amount of energy consumed by the brain is used to run a single molecular machine that maintains the resting potential of neurons. What is this machine called? A. K+ leak channel B. sodium-potassium pump C.acetylcholine receptor D.voltage-gated sodium channel E.voltage-gated calcium channel
B. sodium-potassium pump
Which of the following is not part of the peripheral nervous system? A. sympathetic division of the autonomic nervous system B. spinal cord C. parasympathetic division of the autonomic nervous system D. somatic nervous system E. sensory pathways
B. spinal cord
Since there is a larger concentration of potassium ions inside a neuron, why is the inside of the neuron negative (-70mV) relative to the outside? A.Potassium ions carry a negative charge. B.Negatively-charged proteins inside the cell counteract the charge of the potassium ions. C.The negative sign is just a historical convention. D.The high concentration of sodium ions outside the cell makes the inside negative by comparison.
B.Negatively-charged proteins inside the cell counteract the charge of the potassium ions.
Damage to dopamine-producing neurons can produce the muscle tremors characteristic of what disease? A.epilepsy B.Parkinson disease C.seizures D.Alzheimer disease E.insomnia
B.Parkinson disease
Botulinum toxin-- A toxin produced by the bacterium Clostridium botulinum. Known for sometimes lethal poisoning from infected meat products. In modern controlled medical or cosmetic use, the very same toxin is known as Botox. Tetanus toxin-- Another very potent neurotoxin produced by Clostridium tetani. Strichnine-- A highly poisonous alkaloid produced by the Strychnos nux-vomica tree, historically used to kill rats and other pests. Botulinum toxin, or "botox", has become popular for cosmetic surgery. The toxin prevents neurosecretory vesicles from docking at the plasma membrane and releasing neurotransmitter. How would this toxin affect the neuromuscular junction? A. Since ACh is not released, the muscles stay in a state of repeated contraction. B.Since ACh is not released, the muscles are not activated to contract and remain relaxed. C. Buildup of ACh causes promiscuous activation of all nearby sensory neurons. D. Buildup of ACh leaks back into the brain, creating a calming effect.
B.Since ACh is not released, the muscles are not activated to contract and remain relaxed.
Nodes of Ranvier are the spaces between sections of axon enwrapped with myelin. Because myelin creates an insulating layer that prevents ion flow, the progress of the action potential "jumps" from node to node, thus speeding up transmission down the axon. You are studying a gene which, when mutant, causes oligodendrocytes to enwrap shorter sections of axon, so that nodes of Ranvier are more closely spaced. What is the likely effect on nerve impulses? A.They will travel faster. B.They will travel slower. C.They will increase in amplitude. D. They will decrease in amplitude. E.They will travel laterally across connected axons.
B.They will travel slower.
Which division of the nervous system regulates the activity of smooth muscle, cardiac muscle, and glands? A.antagonistic nervous system B.autonomic nervous system C.sympathetic nervous system D.parasympathetic nervous system E. limbic nervous system
B.autonomic nervous system
In vertebrates, the ______ nervous system is composed of the brain and the spinal cord. A.peripheral B.central C.somatic D.autonomic E.sympathetic
B.central
Where did information processing become increasingly centered in terrestrial vertebrates? A. thalamus B.forebrain C. midbrain D. hindbrain E. medulla oblongata
B.forebrain
What sensory equipment is required for an animal to have binocular vision? A. eyes located to the sides of the head B.forward-facing eyes C.a camera-type eye with multiple lenses D. infrared vision E. ultraviolet vision
B.forward-facing eyes
The simplest sensory receptors are __________ that respond to mechanical distortion, changes in temperature, or specific chemicals. A.nociceptors B.free nerve endings C. gated channels D. photoreceptors E.ganglia
B.free nerve endings
A patient suffers from a disease that slows fatty acid synthesis. What is a likely impact of this disease on nervous system function? A.improved functioning due to a healthier weight B.insufficient myelination and slow axon conduction rate C.improved functioning due to better blood flow D.weaker action potentials with smaller depolarization
B.insufficient myelination and slow axon conduction rate
Which of the following constitute the vestibular apparatus? A.saccule and utricle only B.semicircular canals, saccule, and utricle C.ampullae of Lorenzini D. saccule, utricle, and Organ of Corti E. saccule, utricle, and ventricle
B.semicircular canals, saccule, and utricle
Botulinum toxin-- A toxin produced by the bacterium Clostridium botulinum. Known for sometimes lethal poisoning from infected meat products. In modern controlled medical or cosmetic use, the very same toxin is known as Botox. Tetanus toxin-- Another very potent neurotoxin produced by Clostridium tetani. Strichnine-- A highly poisonous alkaloid produced by the Strychnos nux-vomica tree, historically used to kill rats and other pests. Another toxin that also blocks neurotransmitter release is tetanus toxin; however, it primarily affects inhibitory interneurons of the spinal cord that negatively regulate motor neurons. Which would be symptoms of tetanus toxin poisoning? A.flaccid paralysis B.spastic paralysis C.slowed action potential conduction D. pupil dilation
B.spastic paralysis
What are the sensory structures that enable invertebrates to determine the orientation of the body with respect to gravity called? A.carotid bodies B.statocysts C.Ruffini endings D.baroreceptors E. interoceptors
B.statocysts
What is the name for the gap into which neurotransmitters are released? A.gap junction B.synaptic cleft C. postsynaptic membrane D. presynaptic membrane E. impulse channel
B.synaptic cleft
Your roommate is on an ultra-low fat diet to try to lose weight. Given what you know about structure of the nervous system, what advice would you give him? A. "You should drink large quantities of water, because the brain is mostly water." B. "Good for you! Losing weight by any means necessary can only help your brain." C. "You should eat some healthy unsaturated fats, like those found in fish, olive oil, and nuts, because your brain needs fatty acids to build the myelin sheaths around your axons." D. "You should eat trans fats, from donuts, because 'trans' is short for neurotransmission.
C. "You should eat some healthy unsaturated fats, like those found in fish, olive oil, and nuts, because your brain needs fatty acids to build the myelin sheaths around your axons."
For your birthday, you get a robot-building kit with three parts: 1) a set of gadgets for detecting sound, touch, and light, 2) a set of motors that can move mechanical parts, and 3) a microprocessor that can be programmed to respond to inputs according to predetermined rules. You build a robot car, and find it surprisingly lifelike as it navigates around the room. The three parts of the kit are analogous which parts of the human body? A. 1) autonomic nervous system, 2) somatic nervous system, 3) hypothalamus B. 1) sympathetic pathways, 2) parasympathetic pathways, 3) CNS Correct! C. 1) sensory pathways, 2) motor pathways and muscles, 3) CNS D. 1) motor pathways and muscles, 2) sensory pathways, 3) CNS
C. 1) sensory pathways, 2) motor pathways and muscles,
Which figure correctly illustrates the mechanism of action of the sodium-potassium pump? A. A B. B C. C D. D
C. C
Which region of the CNS listed below is NOT correctly paired with its function? A.Somatosensory cortex—receives sensory input from all parts of the body B.Hypothalamus—regulates body temperature, appetite, thirst, and emotions C. Cerebellum—relay station for ascending and descending tracts D. Corpus callosum—connects the two brain hemispheres E.Auditory cortex—interprets sound information from the ears
C. Cerebellum—relay station for ascending and descending tracts
What are the branched extensions of a neuron that receive signals called? A. axons B. cell bodies C. dendrites D. oligodendrocytes E. synapses
C. dendrites
What region of the brain integrates visceral activities, body temperature, and heartbeat? A. medulla oblongata B. cerebrum C. hypothalamus D. thalamus E. corpus callosum
C. hypothalamus
What sensory receptors sense stimuli that arise from within the body? A. gustatory receptors B. photoreceptors C. interoreceptors D. exteroreceptors
C. interoreceptors
In the vertebrate eye, what structure controls the amount of light that reaches the retina? A. fovea B. cornea C. iris D. lens E. sclera
C. iris
What are the receptors called that transmit impulses that are perceived by the brain as pain? A. baroreceptors B. chemoreceptors C. nociceptors D.thermoreceptors E.propioceptors
C. nociceptors
Botulinum toxin-- A toxin produced by the bacterium Clostridium botulinum. Known for sometimes lethal poisoning from infected meat products. In modern controlled medical or cosmetic use, the very same toxin is known as Botox. Tetanus toxin-- Another very potent neurotoxin produced by Clostridium tetani. Strichnine-- A highly poisonous alkaloid produced by the Strychnos nux-vomica tree, historically used to kill rats and other pests. You accidentally consume botulinum toxin by eating a contaminated can of sausages. What do you predict will be the most harmful physiological effect? A.slowed action potential conduction B.respiratory failure due to spastic paralysis (constant muscle contraction) C. respiratory failure due to flaccid paralysis (relaxed muscles) D. pupil dilation
C. respiratory failure due to flaccid paralysis (relaxed muscles)
In the vertebrate eye, what structure is light focused onto? A. pupil B. lens C. retina D. sclera E. iris
C. retina
What determines the direction of the voltage change that occurs at the postsynaptic membrane? A.the type of neurotransmitter B.the type of second messenger system used C. the type(s) of ions that travel through opened channels D.the number of ion channels on the postsynaptic membrane
C. the type(s) of ions that travel through opened channel
Palytoxin is incredibly toxic, perhaps the second most dangerous non-peptide toxin. It targets the sodium-potassium pump, locking it open and forming a channel through which the ions can passively flow. Palytoxin is produced by zoanthid cnidarians (soft coral), and there have been incidents of poisoning from zoanthids within marine aquaria tanks in people's homes. It is also thought to be the source of the legend of the Limu make o hana ("Seaweed of Death from Hana"). What is the likely impact of this toxin on the resting potential of a neuron? A.The resting potential will require more energy to maintain. B.The resting potential will be more negative. C.It will destroy the ion gradients necessary for the resting potential. D.The resting potential will promote action potentials with a larger depolarization.
C.It will destroy the ion gradients necessary for the resting potential.
The outside of a neuron is positively charged at resting potential. Why do K+ ions leave the cell when K+ channels open during an action potential? A.The diffusion gradient is the only factor that affects ion movement. B.K+ ions are actively pumped out by the sodium-potassium pump acting in reverse. C.Voltage-gated K+ channels open when membrane potential reaches +50 mV during the depolarization phase. The diffusion gradient and electrical force cooperate to drive K+ ions out of the cell. D.Negatively charged proteins leave the cell at the onset of the action potential.
C.Voltage-gated K+ channels open when membrane potential reaches +50 mV during the depolarization phase. The diffusion gradient and electrical force cooperate to drive K+ ions out of the cell.
Palytoxin is incredibly toxic, perhaps the second most dangerous non-peptide toxin. It targets the sodium-potassium pump, locking it open and forming a channel through which the ions can passively flow. Palytoxin is produced by zoanthid cnidarians (soft coral), and there have been incidents of poisoning from zoanthids within marine aquaria tanks in people's homes. It is also thought to be the source of the legend of the Limu make o hana ("Seaweed of Death from Hana"). What is the likely impact of this toxin on action potentials? A.They will occur more frequently. B.They will be stronger and more unpredictable. C.Without ion gradients, action potentials are not possible. D.They will have longer refractory periods.
C.Without ion gradients, action potentials are not possible.
A neuron that engages in spatial summation acquires a mutation that causes dendrite overgrowth and promiscuous synapsing. What is the likely outcome? A. abnormally low frequency of action potentials B. summation will not occur C.abnormally high frequency of action potentials D. action potentials with stronger depolarization
C.abnormally high frequency of action potentials
Which is NOT a stimulus that interoceptors can sense? A.limb position B.pain C.gravity D.body temperature E.muscle length
C.gravity
Which of the following structures is NOT a component of the hindbrain? A.pons B.medulla oblongata C.hypothalamus D.cerebellum
C.hypothalamus
Which sequence of events is required for the brain to interpret sound? I. Vibration of the basilar membrane relative to the tectorial membrane causes cilia on hair cells to bend and triggers depolarization. II. Hair cells stimulate the production of action potentials in sensory neurons that project to the brain. III. Ganglion cell axons transmit action potentials to the occipital lobe. A. II then I B. III then I then II C. III then I D. I then II E. I then II then III
D. I then II
The membrane of a resting neuron is most permeable to which of the following ions? A. Cl- B.Ca2+ C.Na+ D. K+ E. H+
D. K+
If K+ can exit the cell through leak channels, why don't they flow out until there are equal concentrations on both sides of the membrane? A. K+ can act as an enzymatic cofactor, and most K+ ions are bound to cellular enzymes. B.The leak channels allow a very slow leak that cannot keep pace with active import of K+ ions. C. Chelator molecules trap K+ on the inside of the membrane. D. The negative electrical potential inside the cell creates a force that holds the K+ ions in.
D. The negative electrical potential inside the cell creates a force that holds the K+ ions in.
Which is NOT a part of the vertebrate eye? A. cornea B. retina C. iris D. cochlea E. pupil
D. cochlea
When acetylcholine stimulates the opening of ligand-gated ion channels on a postsynaptic cell, what is this event called? A. neuromuscular junction B. temporal summation C. inhibitory postsynaptic potential (IPSP) D. excitatory postsynaptic potential (EPSP) E. synaptic integration
D. excitatory postsynaptic potential (EPSP)
Which of the following cells are NOT found in the retina? A. rods B. cones C. bipolar cells D. hair cells E. ganglion cells
D. hair cells
In early vertebrates, which component of the brain was devoted largely to coordinating motor reflexes? A. thalamus B.forebrain C.midbrain D. hindbrain E. medulla oblongata
D. hindbrain
Which of the following receptors does not trigger depolarization of a sensory neuron? A.mechanoreceptors B.G-protein receptors C.chemoreceptors D. photoreceptors E. exteroceptors and interoceptors
D. photoreceptors
Which of the following is NOT an example of a mechanoreceptor? A.Meissner's corpuscles B. Ruffini endings C. Merkel cells D. red corpuscles E. Pacinian corpuscles
D. red corpuscles
What limits the frequency of action potentials? A.chloride ions B.spike amplitude C. nodes of Ranvier D. refractory period
D. refractory period
Which is NOT a stimulus that the simplest sensory receptors, free nerve endings, will respond to? A. bending of the sensory neuron membrane B. changes in temperature C. changes in the oxygen content of the extracellular fluid D. release of odorants from freshly baked bread E.stretching of the sensory neuron membrane
D. release of odorants from freshly baked bread
What is the site of primary sensory integration in the brain? A. medulla oblongata B. cerebrum C. cerebellum D. thalamus E. corpus callosum
D. thalamus
Which of the following do humans NOT have taste buds specialized to sense? A. salty B. sour C. sweet D. vitamins E. bitter
D. vitamins
Nodes of Ranvier are the spaces between sections of axon enwrapped with myelin. Because myelin creates an insulating layer that prevents ion flow, the progress of the action potential "jumps" from node to node, thus speeding up transmission down the axon. What other cells should you examine for effects from this mutant gene? A.prefrontal neurons B.gustatory neurons C.cholinergic neurons D.Schwann cells
D.Schwann cells
How do temporal and spatial summation improve the processing power of the brain? A. Temporal summation allows circadian rhythms to regulate neuronal activity. Spatial summation allows latitude to regulate neuronal activity. B. Temporal summation allows a neuron to fire prolonged action potentials, and spatial summation allows a neuron to synapse onto new targets. C. Temporal and spatial summation both make the neuron more likely to fire action potentials. D.Temporal summation allows a neuron to recognize a persistent signal from a single presynaptic cell, and spatial summation allows a neuron to recognize a broad signal from multiple presynaptic cells.
D.Temporal summation allows a neuron to recognize a persistent signal from a single presynaptic cell, and spatial summation allows a neuron to recognize a broad signal from multiple presynaptic cells.
The outside of a neuron is positively charged at resting potential. Why don't negative ions exit from the cell to normalize charge across the membrane? A.The positive charge outside the cell repels negative ions. B.There are no negative ions inside the cell. C.All of the chloride ions are already outside the cell. D.The negative charge inside the cell is carried by large proteins that cannot diffuse through the membrane.
D.The negative charge inside the cell is carried by large proteins that cannot diffuse through the membrane.
Where do correlation, association, and learning occur in the brain? A. cerebellum B. corpus callosum C. medulla D.cerebrum E. pons
D.cerebrum
What branched structure allows a neuron to take in information from more than one source? A. node of Ranvier B. axon C.myelin D.dendrite
D.dendrite
To process information, postsynaptic neurons often add up simultaneous signals from several presynaptic neurons. Which structure and process allow them to do so? A.axons; temporal summation B.axons; spatial summation C.dendrites; temporal summation D.dendrites; spatial summation
D.dendrites; spatial summation
Cutaneous receptors are classified as interoceptors. These specialized skin receptors can respond to which of the following stimuli? A.heat, cold, and light B.pain, pressure, and sound C.chemicals, light, and sound D.heat, cold, pain, touch, and pressure E. heat, cold, pain, pressure, light, and sound
D.heat, cold, pain, touch, and pressure
Which of the following stimuli do vertebrates NOT have a specialized receptor for? A.hearing B.taste C.smell D.humidity E.vision
D.humidity
The spinal cord is enclosed by the vertebral column and layers of protective membranes. What are these membranes called? A.neural net B.white matter C.dorsal root D.meninges E.viscera
D.meninges
Which is NOT a stimulus that exteroceptors can sense? A.gravity B.smell C.light D.muscle tension E.sound
D.muscle tension
Dr. Robinson tapped on a patient's knee with the little hammer, but failed to see the usual kick of the patellar reflex. Since this reflex only involves a few neurons, what part of the nervous system might the doctor became concerned about? A.parasympathetic nervous system B.central nervous system C.sympathetic nervous system D.peripheral nervous system
D.peripheral nervous system
When neurons are not producing electrical signals, there is still a voltage difference across their membranes. What is this voltage called? A.channel-gate bias B.electrolyte voltage C.equilibrium potential D.resting potential E ion current
D.resting potential
The word hyponatremia derives from the words hypo ("under" or "less") and natrium ("sodium"). The word natrium is the basis for the abbreviation Na for sodium. Hyponatremia is a rare condition, but has become of more concern with the rise in amateur runners participating in marathons. Since they run slower, they spend longer on the course and have more opportunity to drink water and sweat out additional sodium. Marathon runners are encouraged to stop at water stations along the course to stay hydrated. However, occasionally a runner drinks too much water and suffers from hyponatremia, or "water intoxication". While water itself is not toxic, drinking too much can upset ion balance in the extracellular space. Based on what you know about ions and nerve signaling, the levels of which important ion are most likely to be disrupted in hyponatremia? A.hydrogen B.potassium C.calcium D.sodium E.oxygen
D.sodium
Palytoxin is incredibly toxic, perhaps the second most dangerous non-peptide toxin. It targets the sodium-potassium pump, locking it open and forming a channel through which the ions can passively flow. Palytoxin is produced by zoanthid cnidarians (soft coral), and there have been incidents of poisoning from zoanthids within marine aquaria tanks in people's homes. It is also thought to be the source of the legend of the Limu make o hana ("Seaweed of Death from Hana"). A Hawaiian legend tells of a village that angered a shark god. In revenge, a "seaweed" began to grow in the tidepools that killed anyone who touched it. In fact, this "limu-make-o-Hana" -- a zoanthid cnidarian -- contains a palytoxin that locks the sodium-potassium pump open, allowing free flow of ions. If a villager suffers palytoxin poisoning, which way will the ions in his neurons flow? A.all ions will flow out B.potassium in, sodium out C.chloride and sodium out, potassium in D.sodium in, potassium out
D.sodium in, potassium out
What part of the neuron is responsible for most of the "house-keeping" tasks of the cell, including protein synthesis? A.myelin B.axon C.dendrite D.soma E.synapse
D.soma
Which correctly represents the sequence of steps involved to convey sensory information to the CNS? A.stimulation and ion flow through the synaptic cleft B.neurotransmitter release and interpretation C.neurotransmitter release and ion flow through the synaptic cleft D.stimulation, transduction, transmission, and interpretation E.stimulation, transmission, and neurotransmitter release
D.stimulation, transduction, transmission, and interpretation
Which of the following are components of vertebrate gravity receptors? I-Utricle and saccule chambers of a membranous labyrinth. II-Hair cells with stereocilia and kinocilium. III-Hairlike processes embedded with otolith membrane, a gelatinous membrane containing calcium carbonate crystals. IV-Peripheral chemoreceptors. A. I and II only B. II, III, and IV C. I and IV only D. I, II, and IV E. I, II, and III
E. I, II, and III
Which of the following characteristics are true for an action potential? I-A threshold potential must be exceeded for an action potential to occur. II-A stimulus either produces a full action potential or none at all. III-During the refractory period it is less likely that stimuli can produce another action potential. A. I only B. I and II C. II and III D. I and III E. I, II, and III
E. I, II, and III
What are examples of cells that support neurons both structurally and functionally? A. dendrites and nodes of Ranvier B.neuroglia and nodes of Ranvier C. Schwann cells and dendrites D. dendrites, nodes of Ranvier, and neuroglia E. Schwann cells, oligodendrocytes, and other neuroglia
E. Schwann cells, oligodendrocytes, and other neuroglia
What is the primary function of the hindbrain in vertebrates? A. temperature control B. integration of sensory data C. memory storage D. control of the heartbeat E. coordination of motor reflexes
E. coordination of motor reflexes
Which of the following are example of biogenic amines? A.epinephrine and endorphins B. GABA and serotonin C. epinephrine, dopamine, and GABA D. epinephrine, dopamine, and serotonin E. epinephrine, norepinephrine, dopamine, and serotonin
E. epinephrine, norepinephrine, dopamine, and serotonin
Which major regions compose the contemporary vertebrate brain? A. rhombencephalon and prosencephalon only B. mesencephalon and rhombencephalon only C. prosencephalon and metencephalon only D. metencephalon, rhombencephalon, and prosencephalon E. rhombencephalon, mesencephalon, and prosencephalon
E. rhombencephalon, mesencephalon, and prosencephalon
What is the process in which impulses jump from node to node? A.facilitated transmission B.refractory action C. incomplete transfer D. repolarization E. saltatory conduction
E. saltatory conduction
Place the following events that occur at the vertebrate neuromuscular junction in the correct order. I-Depolarization of the muscle fiber membrane. II-Generation of an action potential in the neuron. III-Stimulation of Ca2+ entry into the neuron. IV-Release of acetylcholine into the synapse. A.I, II, III, IV B. III, II, IV, I C.I, III, IV, II D.IV, II,III, I E.II, III, IV, I
E.II, III, IV, I
Rapid inward diffusion of Na+ produces a dramatic change in membrane potential. What is this event called? A.hyperpolarization B.excitatory postsynaptic potential C.saltatory conduction D.monosynaptic reflex E.depolarization
E.depolarization
Which of the following stimuli will NOT activate a nociceptor? A.extremes in temperature B.very intense mechanical stimulation C.specific chemicals in the extracellular fluid D.chemicals released by injured cells E.external odorant molecules
E.external odorant molecules
The lateral line system provides ________ with a sense of "distant touch," enabling these animals to sense objects that reflect pressure waves and low-frequency vibrations. A.adult amphibians B.reptiles C.birds D.mammals E.fish
E.fish
Which includes all of the components that make up the Organ of Corti? A.the basilar membrane only B.the tectorial and basilar membranes C. hair cells and associated neurons only D.hair cells and the tectorial membrane E.hair cells and the basilar and tectorial membranes
E.hair cells and the basilar and tectorial membranes
What important resource do Schwann cells and oligodendrocytes provide to neurons? A.oxygen B.nutrients C.physical strength from microtubules D.Ca2+ currents E.insulating layers of membrane
E.insulating layers of membrane