Deck 43: The Nervous System

Question 1

What other cells should you examine for effects from this mutant gene?

A)prefrontal neurons
B)gustatory neurons
C)cholinergic neurons
D)Schwann cells

Answer 1

D

Question 2

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

Answer 2

B

Question 3

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

Answer 3

C

Question 4

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)

Question 5

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.

Question 6

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

Question 7

Which neurotransmitter is released from a motor neuron at the neuromuscular junction?

A)acetylcholine
B)GABA
C)ephinephrine
D)dopamine

Question 8

What is the elongated extension of a neuron that nerve impulses travel along?

A)axon
B)cell body
C)dendrite
D)oligodendrocyte

Question 9

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

Question 10

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

Question 11

Place the following events involved in drug addiction in the correct sequence.I-The synapse becomes less sensitive, and normal function can only continue in the presence of the drug.II-CNS responds to increased firing by decreasing the number of drug receptors on the cell membrane.III-Drug molecule prevents receptor endocytosis and causes overstimulation of the postsynaptic cell.

A)I, II, III
B)III, II, I
C)II, III, I
D)III, I, II

Question 12

The hippocampus, amygdala, and hypothalamus are the major components of the ______ system.

A)sympathetic
B)reflex
C)parasympathetic
D)limbic

Question 13

The membrane of a resting neuron is most permeable to which of the following ions?

A)Cl^-
B)Ca²⁺
C)Na⁺
D)K⁺

Question 14

In vertebrates, the ______ nervous system is composed of the brain and the spinal cord.

A)peripheral
B)central
C)somatic
D)autonomic

Question 15

Which figure correctly illustrates the mechanism of action of the sodium-potassium pump?

A)A
B)B
C)C
D)D

Question 16

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.

Question 17

You dissect the brain of a mutant mouse and find that parts of the "white matter" look gray.What is a likely cause?

A)defects in myelination
B)peripheral nerve damage
C)oversized dendrites
D)excess myelination

Question 18

Nerve impulses are electrical signals measured across which structure?

A)lipid sheath of Schwann cell
B)plasma membrane of neuron
C)synapse
D)neuromuscular junction

Question 19

What is the name for the gap into which neurotransmitters are released?

A)gap junction
B)synaptic cleft
C)postsynaptic membrane
D)presynaptic membrane

Question 20

What are the branched extensions of a neuron that receive signals called?

A)axons
B)cell bodies
C)dendrites
D)oligodendrocytes

Question 21

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

Question 22

The doctor informs you that your grandmother's stroke has caused damage to Wernicke's area.Which activity is likely to become more difficult for her?

A)walking
B)doing laundry
C)having a conversation
D)sleeping

Question 23

What region of the brain integrates visceral activities, body temperature, and heartbeat?

A)medulla oblongata
B)cerebrum
C)hypothalamus
D)thalamus

Question 24

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 most likely be concerned about?

A)parasympathetic nervous system
B)central nervous system
C)sympathetic nervous system
D)peripheral nervous system

Question 25

What additional factor is required to mediate the parasympathetic effects of acetylcholine?

A)G-protein coupled receptor
B)GABA
C)AMPAR
D)habituation

Question 26

A cheetah is chasing a gazelle.What division of the vertebrate nervous system is regulating the stress response in both animals?

A)somatic nervous system
B)parasympathetic nervous system
C)sympathetic nervous system
D)parasymbiotic nervous system

Question 27

Which area of the cerebral cortex is important for the formulation of thoughts into speech?

A)Broca's area
B)the pons
C)the medulla oblongata
D)Wernicke's area

Question 28

Damage to the substantia nigra, a specific region of the basal ganglia, can produce the resting muscle tremors characteristic of what disease?

A)epilepsy
B)Parkinson disease
C)seizures
D)Alzheimer disease

Question 29

A cheetah has succeeded in catching a gazelle and has just finished feeding on the carcass.What division of the nervous system has increased in activity?

A)somatic nervous system
B)parasympathetic nervous system
C)sympathetic nervous system
D)parasymbiotic nervous system

Question 30

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

Question 31

Where do correlation, association, and learning occur in the brain?

A)cerebellum
B)corpus callosum
C)medulla
D)cerebrum

Question 32

In early vertebrates, which component of the brain was devoted largely to coordinating motor reflexes?

A)thalamus
B)forebrain
C)midbrain
D)hindbrain

Question 33

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

Question 34

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

Question 35

Which animal phylum lacks a network of nerve cells for gathering information from the environment?

A)Porifera - sponges
B)Cnidaria - jellyfish, sea anenomes
C)Platyhelminthes -- flatworms
D)Nematoda - roundworms

Question 36

What is the site of primary sensory integration in the brain?

A)medulla oblongata
B)cerebrum
C)cerebellum
D)thalamus

Question 37

Which region of the CNS listed below is NOT correctly paired with its function?

A)Broca's and Wernicke's areas-language and speech
B)Hypothalamus-regulates body temperature, appetite, and sleep
C)Cerebellum-relay station for ascending and descending tracts
D)Corpus callosum-connects the two brain hemispheres

Question 38

Where did information processing become increasingly centered in terrestrial vertebrates?

A)thalamus
B)forebrain
C)midbrain
D)hindbrain

Question 39

Which of the following structures is NOT a component of the hindbrain?

A)pons
B)medulla oblongata
C)ascending tracts
D)cerebellum

Question 40

A region of the brain receives both sensory information from ascending nerve tracts and motor commands from the cortex and cerebellum.This region plays an important role in motor control.Which region is it?

A)basal ganglia
B)pituitary gland
C)parietal lobe
D)thalamus

Question 41

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 PMP22 gene important for normal function?

A)Schwann cells
B)preganglionic neurons
C)postganglionic neurons
D)oligodendrocytes

Question 42

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

Question 43

What do the two sets of neurons damaged in Charcot-Marie-Tooth neuropathy comprise?

A)peripheral nervous system
B)autonomic nervous system
C)somatic nervous system
D)parasympathetic nervous system

Question 44

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.

Question 45

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

Question 46

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

Question 47

You are an EMT on duty for the marathon.It is an extremely hot day.You say to your partner, "This weather is likely to _____________ the risk of hyponatremia, because ______________ will cause the athletes to lose ______________."

A)increase, sweating, sodium
B)decrease, urination, calcium
C)decrease, shivering, potassium
D)increase, panting, oxygen

Question 48

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

Question 49

Subsequent to motor neuron degeneration in Charcot-Marie-Tooth disease, muscles begin to weaken and degenerate as well.What is the likely cause?

A)Muscles will atrophy if they don't receive regular stimulation from motor neurons.
B)Muscles require healthy Schwann cells for myelination as well.
C)Muscles contain large numbers of mitochondria.
D)Toxins leak out from the dying motor neurons onto the muscles.

Question 50

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

Question 51

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

Question 52

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.

Question 53

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."

Question 54

True or false: When a neuron is not firing, the sodium-potassium pump is inactive.

Question 55

True or false: neurons are the only electrically-active cells.

Question 56

How can mutations in different genes, functioning in different cells, lead to the same disease? From the following, choose the best responses to complete the sentences: "Physiological function requires that multiple cells work together.Various defects in different cells can impair function, leading to ___________ that are indistinguishable at the level of the whole organism.In Charcot-Marie-Tooth disease, motor nerve function can be impaired either by a problem within _______________ , or a problem in __________________ causing _______________."

A)defects; somatic cells; oligodendrocytes; demyelination
B)symptoms; motor neurons; Schwann cells; demyelination
C)symptoms; sensory neurons; Schwann cells; fast axonal transport
D)genotypes; dendrites; axons; fast axonal transport

Question 57

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

Question 58

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

Question 59

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

Question 60

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

Question 61

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.

Question 62

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.

Question 63

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.

Question 64

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.

Question 65

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.

Question 66

How do somatic neurons and autonomic neurons differ? (Check all that apply.)
_____ Somatic neurons innervate the body surface, while autonomic neurons innervate internal structures.__X__ Somatic neurons control skeletal muscle, while autonomic neurons control smooth and cardiac muscle._____ Somatic neurons control exocrine glands, while autonomic neurons do not.__X__

Question 67

What would happen if the G-protein coupled receptor in heart cells that binds to ACh had a mutation that caused it to bind more tightly to the G-protein alpha subunit?

A)G-protein activation and K+ channel opening would happen more quickly.Heart rate may remain abnormally low, impairing response to stress.
B)This would lead to K+ flow out of heart cells, causing increased hyperpolarization.
C)G-protein activation and K+ channel opening would be slowed.Heart rate may remain abnormally high, especially following stress.
D)This would lead to K+ flow into heart cells, causing increased depolarization.

Question 68

What limits the frequency of action potentials?

A)chloride ions
B)spike amplitude
C)nodes of Ranvier
D)refractory period

Question 69

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

Question 70

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.

Question 71

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.

Question 72

In contrast to these toxins, strychnine acts postsynaptically, to block glycine from binding to receptors on motor neurons.Would you expect the symptoms of strychnine poisoning to be more similar to those of botulinum or tetanus toxin?

A)botulinum
B)tetanus toxin
C)botulinum

Question 73

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.

Question 74

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.

Question 75

A patient of yours is injured in a car accident.The surgeon reports that while there is damage to the dorsal roots, the spinal cord and nerves otherwise appear intact.What functions would you expect to be affected in the patient?

A)The patient may lose somatic function, but should retain autonomic function.
B)The patient may lose motor function, but should retain sensory perception.
C)The patient may lose some sensory perception, but should retain motor function.However, lack of proprioceptive input may make muscle control difficult.
D)The patient may lose parasympathetic function, but should retain sympathetic function.They should avoid stressful situations.

Question 76

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.

Question 77

K⁺ channels in the heart do not have binding sites for ACh, yet parasympathetic release of ACh causes outward flux of K⁺ from heart cells.How does this occur?

A)ACh triggers release of epinephrine from the adrenal glands, which in turn causes K+ flux out of heart cells.
B)ACh binds to a G-protein coupled receptor on heart cells, and the G protein alpha subunit binds to a separate K⁺ channel and causes it to open.
C)Parasympathetic neurons activate sympathetic neurons, which directly cause K⁺ flux from heart cells.
D)ACh binds and activates a K⁺ pump on heart cells.

Question 78

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