Sensory Physiology Questions for Practice

Sensory receptors that respond when body temperature is below normal are called A) warm receptors. B) photoreceptors. C) cold receptors. D) All receptors respond to temperatures above and below body temperature (no unique name).

C

A receptor potential is A) an action potential. B) a graded potential. C) the resting membrane potential of a receptor cell. D) always converted to an action potential in sensory receptor cells.

B

Sharp, localized (fast) pain is rapidly transmitted to the central nervous system along A) large, unmyelinated C fibers. B) small, myelinated A-delta fibers. C) small, unmyelinated C fibers. D) large, myelinated A-beta fibers.

B

The brain's association of activation of a receptor with the perception of a particular sensation is called ________.

labeled line coding

50. Perceptions are derived from higher-order processing of sensory information. True False

t

51. The transmission of information in a sensory system is analogous to the transmission of sound in a telephone system except that, unlike the telephone system, the sensory system does not retranslate the electrical signaling code back to the specific energy of the stimulus. True False

t

54. The rate of change of a stimulus may be important in determining receptor response. True False

t

56. Highly processed sensory information is invested with emotional significance by neurons in the association cortex of the temporal lobes. True False

t

32) Which ion(s) is/are higher in concentration inside the cell compared to outside? A) potassium B) sodium C) chloride D) calcium E) more than one of the above

A

A decrease in ones perception of a stimulus whose intensity has not changed due to higher neural inhibition is A) habituation. B) convergence. C) divergence. D) adaptation.

A

All of the following must occur before a second action potential can begin, EXCEPT A) the Na+ and K+ ions that moved in/out of the cell must move back to their original compartments. B) the Na+ inactivation gate must open and the Na+ activation gate must close. C) the absolute refractory period must occur. D) A and B E) none of the above

A

An increased threshold is associated with the __________ refractory period. A) absolute B) relative

A

Excitatory neurotransmitters of the CNS usually act by opening __________ channels. A) Na+ B) K+ C) Cl- D) H+ E) Ca2+

A

How would the absolute refractory period be affected if voltage-gated sodium channels remained inactivated? A) It would be longer than normal. B) It would be shorter than normal. C) It would be the same whether the channels remained inactivated or not. D) none of the above

A

The all-or-none principle states that A) all stimuli will produce identical action potentials. B) all stimuli great enough to bring the membrane to threshold will produce action potentials of identical magnitude. C) the greater the magnitude of the stimuli, the greater the intensity of the action potential. D) only sensory stimuli can activate action potentials. E) only motor stimuli can activate action potentials

A

The inactivation gate A) quickly opens and closes after depolarization. B) is coupled to the movement of the activation gate, but is much slower. C) depends on a change of +100 mV from rest to be signaled to close. D) depends on a loss of Na+ permeability to be triggered. E) depends on a loss of K+ permeability to be triggered

A

The rising phase of the action potential is due to A) Na+ flow into the cell. B) Na+ flow out of the cell. C) K+ flow out of the cell. D) K+ flow into the cell. E) B and D

A

3) Neurotransmitter is stored and released from A) axon terminals. B) axon varicosities. C) dendritic spines. D) cell bodies. E) A and B

A and B

4) Information coming into the central nervous system is transmitted along __________ neurons. A) afferent B) sensory C) efferent D) A and B E) B and C

A and B

A chemical synapse ALWAYS includes __________. 1. axon terminal 2. presynaptic cell 3. synaptic cleft 4. postsynaptic cell 5. dendrite A) 1, 2, 3, 4, 5 B) 1, 2, 3, 4 C) 2, 3, 4 D) 2, 3, 4, 5 E) 1, 3, 4

B

Arrange the following events in the proper sequence. 1. Efferent neuron reaches threshold and fires an action potential. 2. Afferent neuron reaches threshold and fires an action potential. 3. Effector organ responds by performing output. 4. Integrating center reaches decision about response. 5. Sensory organ detects change in the environment. A) 2, 3, 5, 1, 4 B) 5, 2, 4, 1, 3 C) 5, 1, 4, 2, 3 D) 5, 3, 4, 2, 1 E) 3, 1, 4, 2, 5

B

Calcium is important in the synapse because it A) is necessary for acetylcholine synthesis. B) signals the exocytosis of the neurotransmitter. C) binds to receptors on the postsynaptic cell, opening ion channels, and triggering graded potentials. D) leaves the axon terminal, hyperpolarizing the cell.

B

If a hyperpolarizing graded potential and a depolarizing graded potential of similar magnitudes arrive at the trigger zone at the same time, what happens? A) An action potential is fired off more quickly than usual. B) Nothing. They will cancel each other out. C) The cell becomes hyperpolarized. D) The cell becomes easier to excite. E) The cell dies.

B

In order to signal a stronger stimulus, action potentials become A) higher in amplitude. B) more frequent. C) longer lasting. D) A and B E) A and C

B

Inhibitory postsynaptic potentials (IPSPs ) A) result in local depolarizations. B) result in local hyperpolarizations. C) increase membrane permeability to sodium ions. D) prevent the escape of potassium ions. E) prevent the escape of calcium ions.

B

Spatial summation refers to A) electrical signals reaching neurons from outer space. B) multiple graded potentials arriving at one location simultaneously. C) repeated graded potentials reaching the trigger zone one after the other. D) suprathreshold potentials triggering action potentials that are extra large. E) all of the above

B

The following are the main steps in the generation of an action potential. 1. sodium channels are inactivated 2. voltage-regulated potassium channels open and potassium moves out of the cell, initiating repolarization 3. sodium channels regain their normal properties 4. a graded depolarization brings an area of an excitable membrane to threshold 5. a temporary hyperpolarization occurs 6. sodium channel activation occurs 7. sodium ions enter the cell and further depolarization occurs The proper sequence of these events is A) 4, 6, 7, 3, 2, 5, 1. B) 4, 6, 7, 1, 2, 5, 3. C) 6, 7, 4, 1, 2, 3, 5. D) 2, 4, 6, 7, 1, 3, 5. E) 4, 2, 5, 6, 7, 3, 1.

B

The larger the receptive field, the A) stronger the stimulus intensity required to activate a sensory receptor. B) more primary sensory neurons synapse on a secondary sensory neuron. C) fewer primary sensory neurons are involved. D) larger the area of the somatosensory cortex in the brain that perceives the sensation.

B

The neurotransmitter thought to be involved in learning and memory is A) norepinephrine. B) glutamate. C) acetylcholine. D) GABA. E) glycine.

B

The pattern of synaptic connectivity where a large number of presynaptic neurons provide input to a single postsynaptic neuron, is known as A) divergence. B) convergence. C) integration. D) saltatory conduction. E) potentiation.

B

When a second EPSP arrives at a single synapse before the effects of the first have disappeared, what occurs? A) spatial summation B) temporal summation C) inhibition of the impulse D) hyperpolarization E) decrease in speed of impulse transmission

B

When voltage-gated K+ channels of a resting neuron open, A) K+ enters the neuron. B) K+ leaves the neuron. C) the neuron depolarizes. D) A and C E) B and C

B

Which of the following will increase the conduction rate of action potentials? A) Increase the diameter of the axon, decrease the resistance of the axon membrane to ion leakage. B) Increase the diameter of the axon, increase the resistance of the axon membrane to ion leakage. C) Decrease the diameter of the axon, decrease the resistance of the axon membrane to ion leakage. D) Decrease the diameter of the axon, increase the resistance of the axon membrane to ion leakage.

B

Which of the following would be an adequate stimulus for a mechanoreceptor? A) oxygen B) cell stretch C) photon of light D) cold temperature E) pH

B

With the exception of olfaction, all sensory pathways first travel to the ________, which acts as a relay and processing station. A) cerebrum B) thalamus C) cerebellum D) hypothalamus E) medulla oblongata

B

12) Interneurons are found A) only in the brain. B) only in the spinal cord. C) only in the CNS. D) throughout the nervous system. E) only in spinal nerves.

C

13) The multiple thin, branched structures on a neuron whose main function is to receive incoming signals are the A) cell bodies. B) axons. C) dendrites. D) somata. E) none of the above

C

20) The term axonal transport refers to A) the release of neurotransmitter molecules from the axon. B) the transport of microtubules to the axon for structural support. C) vesicle transport of proteins and organelles down the axon. D) the movement of the axon terminal to synapse with a new postsynaptic cell. E) none of the above

C

35) The total amount of neurotransmitter released at the axon terminal is directly related to A) the amplitude of the action potential. B) the length of the axon. C) the total number of action potentials. D) the amplitude of the graded potential.

C

An excitatory postsynaptic potential (EPSP) A) depolarizes a neuron, decreasing the likelihood of an action potential. B) hyperpolarizes a neuron, decreasing the likelihood of an action potential. C) depolarizes a neuron, increasing the likelihood of an action potential. D) hyperpolarizes a neuron, increasing the likelihood of an action potential.

C

Convergence describes A) the reason why receptive fields are so small. B) how one primary sensory receptor neurons synapses with a secondary neuron. C) how multiple primary sensory neurons synapse on a single secondary neuron. D) how receptive fields can overlap with one another

C

Identify the FALSE statement regarding sensory receptor cells. A) Threshold is the minimal stimulus intensity required to generate an action potential. B) Sensory transduction converts stimulus energy into a receptor potential. C) Each type of sensory receptor responds only to the stimulus that defines the receptor. D) A graded potential is referred to as a receptor potential. E) Many sensory receptor cells are NOT nerve cells.

C

Temporal summation refers to A) the temporal lobe of the brain integrating neuronal interaction. B) multiple graded potentials originating from different locations simultaneously. C) additional graded potential(s) arriving before previous ones have ceased. D) suprathreshold potentials triggering action potentials that are extra large. E) All of the above accurately describe temporal summation.

C

The falling phase of the action potential is due primarily to A) Na+ flow in the cell. B) Na+ flow out of the cell. C) K+ flow out of the cell. D) K+ flow into the cell. E) B and D

C

The ion necessary to initiate the release of acetylcholine into the synaptic cleft is A) sodium. B) potassium. C) calcium. D) chloride. E) zinc.

C

The major determinant of the resting potential of all cells is A) Ca2+ concentration in the blood and interstitial fluid. B) Na+ concentration in the blood and interstitial fluid. C) K+ gradient between the blood and interstitial fluid. D) K+ concentration inside cells. E) Na+ concentration inside cells.

C

The two-point discrimination test A) is used to determine clarity of vision. B) provides information about olfactory receptors. C) provides a measure of receptive field size for touch receptors. D) is used to test for hearing disorders. E) monitors the activity of taste buds.

C

To increase the amount of neurotransmitter released onto a postsynaptic cell, the presynaptic cell would have to A) send action potentials with higher voltage (higher amplitude). B) send action potentials with longer durations. C) send action potentials with higher frequency. D) do nothing; no change is possible since the all-or-none law is in effect.

C

Voltage-regulated channels are located A) within the cytosol. B) in the membranes of dendrites. C) in the membranes of axons. D) on the neuron cell body. E) all of the above

C

Which of the following is NOT a somatosensory modality? A) proprioception B) touch C) vision D) nociception E) temperature

C

14) The structure on the neuron that transmits electrical signals to trigger the release of neurotransmitter is the A) axon hillock. B) varicosity. C) axon. D) dendrite. E) nerve.

D

31) The resting membrane potential results from A) uneven distribution of ions across the cell membrane. B) differences in membrane permeability to Na+ and K+. C) activity of the sodium/potassium pump. D) A and B E) none of the above

D

4) A graded change in membrane potential within a sensory receptor cell is always called a(n) A) depolarization. B) hyperpolarization. C) action potential. D) receptor potential.

D

5) The afferent and efferent axons together form the A) central nervous system. B) autonomic division system. C) somatic motor division of the nervous system. D) peripheral nervous system. E) visceral nervous system.

D

Graded potentials can A) act as signals over short distances. B) act as signals over long distances. C) cause or prevent an action potential. D) A and C E) B and C

D

If an electrode is placed in the middle of a resting axon and an above-threshold voltage is applied, action potentials A) will not occur. B) will start at that point and proceed only toward the axon terminal. C) will start at that point and proceed only toward the cell body. D) will start at that point and travel in both directions in the axon.

D

Tetrodotoxin is a toxin that blocks voltage-gated sodium channels. What effect does this substance have on the function of neurons? A) Neurons depolarize more rapidly. B) Action potentials lack a repolarization phase. C) The absolute refractory period is shorter than normal. D) The neuron is not able to propagate action potentials. E) The toxin does not interfere with neuron function because the voltage-regulated sodium channels would still function.

D

The intensity of a stimulus can be determined within the central nervous system by A) population coding only. B) labeled line coding only. C) frequency coding only. D) population coding and/or frequency coding. E) labeled line coding and/or frequency coding.

D

The modality of a stimulus can be determined within the central nervous system by A) population coding. B) lateral inhibition. C) frequency coding. D) adequate stimulus for the sensory receptor cell.

D

The perception threshold describes the A) intensity of stimulus required to generate a receptor potential. B) intensity of stimulus required to generate an action potential. C) convergence of information from multiple primary sensory neuron onto a single secondary neuron. D) concept that neurons higher in the sensory pathway can dampen the intensity of a stimulus.

D

The point during an action potential when the inside of the cell has become more positive than the outside is known as the A) depolarization. B) rising phase. C) falling phase. D) overshoot. E) peak.

D

When comparing action potentials to graded potentials, an important distinguishing characteristic is A) only graded potentials can undergo summation. B) only action potentials can undergo summation. C) the rate of action potentials is limited by the refractory period. D) A and C E) B and C

D

When voltage-gated Na+ channels of a resting neuron open, A) Na+ enters the neuron. B) Na+ leaves the neuron. C) the neuron depolarizes. D) A and C E) B and C

D

Which is/are the most common inhibitory neurotransmitter(s) of the CNS? A) GABA B) glycine C) glutamate D) A and B E) all of the above

D

Which of the following statements regarding pathways for somatic perception projection is correct? A) The tertiary sensory neurons cross-over the body's midline. B) The synapse for the secondary to tertiary sensory neuron is within the medulla. C) The longest of the secondary sensory neurons transmit fine touch and proprioceptive information. D) Primary sensory neurons from the hands project to a specific region of the somatosensory cortex. E) Primary sensory neurons that respond to cold sensation project to the same region of the somatosensory cortex.

D

Choose all the items that are incorrectly matched. A) activation gate - closed at rest B) inactivation gate - open at rest C) inactivation gate - opens during repolarization D) activation gate - opens during depolarization E) All of the above are incorrectly matched

E

During the relative refractory period, __________ gates are open. A) sodium B) potassium C) calcium D) chloride E) A and B

E

During the relative refractory period, an initial threshold-level depolarization is usually not sufficient to trigger an action potential. Why? A) Only some Na+ channels have returned to their resting position. B) K+ channels are still open, so Na+ entry is offset by K+ loss. C) Only a few K+ channels have returned to their resting position. D) The statement is incorrect; a threshold-level depolarization always triggers an action potential. E) A and B

E

Graded potentials may A) initiate an action potential. B) depolarize the membrane to the threshold voltage. C) hyperpolarize the membrane. D) be called EPSPs or IPSPs. E) All of the above are true.

E

In response to binding a neurotransmitter, a postsynaptic cell can A) open chemically gated ion channels, causing graded potentials known as fast synaptic potentials. B) close ion channels via G proteins and second messenger systems, producing slow responses. C) regulate protein synthesis and affect the metabolic activities of the postsynaptic cell. D) A and C E) A, B, and C

E

Inhibitory neurotransmitters of the CNS act by opening __________ channels. A) Na+ B) Cl- C) K+ D) Ca2+ E) Cl- or K+

E

The absolute refractory period of an action potential A) ensures one-way travel down an axon. B) allows a neuron to ignore a second signal sent that closely follows the first. C) prevents summation of action potentials. D) A and B E) A, B, and C

E

The sodium-potassium exchange pump A) must re-establish ion concentrations after each action potential. B) transports sodium ions into the cell during depolarization. C) transports potassium ions out of the cell during repolarization. D) moves sodium and potassium in the direction of their chemical gradients. E) requires ATP to function.

E

Which of the following are responsible for a receptor adapting to a stimulus? A) K+ channel inactivation only B) Na+ channel inactivation only C) opening of Na+ channels only D) opening of K+ channels only E) Na+ channel inactivation or K+ channel opening

E

Which of the following does NOT influence the time necessary for a nerve impulse to be conveyed by a particular neuron? A) length of the axon B) presence or absence of a myelin sheath C) diameter of the axon D) presence or absence of nodes of Ranvier E) whether axon is sensory or motor

E

16. Which of the following statements regarding sensory pathways is correct? A. All somatic sensory information that reaches the cerebral cortex is first processed in the thalamus. B. Somatic sensory information from the left side of the body projects to the left side of the somatosensory cortex. C. All somatic sensory information travels together in a single tract in the spinal cord. D. Ascending pathways in the anterolateral column of the spinal cord carry information about fine touch discrimination. E. Ascending pathways in the dorsal column of the spinal cord carry information about pain from the back muscles.

a

9. Which of the following is most important for the determination of stimulus type? A. the relative sensitivity of different receptors to different stimulus energies B. the presence of polymodal neurons in the sensory pathway C. the intensity of a stimulus D. the location on the body where a stimulus is applied E. propagation of a signal along a nonspecific ascending pathway

a

13. Which best describes lateral inhibition in the somatic sensory system? A. The frequency of action potentials along pathways from the site of a stimulus is increased by lateral inhibition. B. The precision of locating a stimulus is increased by inhibiting signaling along nearby, parallel pathways. C. The precision of locating a stimulus is enhanced by increasing the frequency of action potentials in nearby, parallel pathways. D. Stimuli of one particular modality in a region of the body block transmission of action potentials coding for other modalities generated in the same region of the body. E. Lateral inhibition reduces the contrast between the frequency of action potentials generated at the center of a stimulus and the frequency of action potentials in surrounding pathways.

b

7. Polymodal neurons are: A. afferent neurons. B. interneurons that receive synaptic input from different kinds of sensory units. C. part of specific ascending sensory pathways. D. interneurons that receive synaptic input from only one type of sensory unit. E. efferent neurons.

b

8. Which is an accurate description of the cortical association areas? A. They are all found in the parietal lobe of the cerebral cortex. B. They integrate multiple types of sensory information and are responsible for complex processing of sensory information. C. They are the cortical locations where primary sensory information first arrives from specific ascending pathways. D. They are found deep in the cerebrum, surrounding the thalamus. E. Their main input is sensory information arriving along neurons that project directly from the thalamus.

b

1. Which of the following statements regarding sensory systems is correct? A. All sensory information that reaches the brain can be experienced as a conscious sensation. B. Sensory information that leads to conscious awareness of the stimulus is called transduction. C. The term, "sensory unit," refers to a group of receptors that receive a particular stimulus and the afferent neuron associated with those receptors. D. The term "adequate stimulus" means that a stimulus is strong enough to be detected. E. Some sensory receptors are modifications of the peripheral endings of efferent neurons.

c

10. Which of these is one reason you can distinguish between a needle prick on the foot and an ice cube on the wrist? A. The ice cube stimulates a different class of receptors than the needle prick, even though both signals go to exactly the same location in the brain. B. The action potentials from the needle prick are inherently different from the impulse generated by the ice cube. C. The region of the brain to which one receptor pathway leads is different from the region to which the other pathway leads. D. The needle prick generates a stronger action potential in any one neuron than an ice cube does. E. The needle prick generates a higher frequency of action potentials than the ice cube does.

c

15. Which of the following would NOT be categorized as a "somatic" sensation? A. pressure B. cold and warmth C. sound D. proprioception E. kinesthesia

c

18. Which of the following symptoms would a patient with a lesion (injury) that destroyed the right side of the spinal cord in the region of the neck be most likely to experience? A. loss of both pressure sense and pain in the right foot B. loss of both pressure sense and pain in the left foot C. loss of pressure sense in the right foot and pain in the left foot D. loss of pressure sense in the left foot and pain in the right foot

c

2. Which is TRUE about receptor potentials? A. They are action potentials. B. They always trigger action potentials. C. They vary in magnitude with stimulus strength. D. They propagate without decrement. E. They generally occur at the axon hillock of afferent neurons.

c

3. A sensory unit is defined as A. all of the sensory receptors in a given area of the body that respond to the same stimulus. B. a single receptor ending and its afferent nerve fiber. C. a single afferent neuron and all its receptor endings. D. an afferent neuron and its postsynaptic interneurons. E. a reflex composed of an afferent neuron, an interneuron, and an efferent neuron.

c

6. Which is TRUE regarding the ascending pathways in the sensory system? A. Specific pathways for auditory stimuli project primarily to the frontal lobes of the cerebral cortex. B. Specific pathways for all sensory information synapse in the somatosensory cortex. C. Specific pathways for olfaction synapse in the limbic system. D. Specific pathways for visual stimuli project primarily to the frontal lobes of the cerebral cortex. E. Specific pathways for pain project primarily to the occipital lobes of the cerebral cortex.

c

11. Which of the following statements regarding the determination of stimulus intensity is true? A. Stronger intensity stimuli cause rapid adaptation, while weaker stimuli cause slower adaptation. B. The amplitude of action potentials increases with increasing stimulus intensity. C. The duration of receptor potentials decreases with increasing stimulus intensity. D. The frequency of action potentials increases with increasing stimulus intensity. E. The only means of detecting intensity changes is through recruitment of greater numbers of sensory units.

d

14. A stimulus to which afferent neurons X, Y and Z are sensitive is applied in the middle of Y's receptive field. The same stimulus simultaneously activates receptors on the periphery of the receptive fields of X and Z. Which of the following is likely to be true? A. The receptor potential in neurons X and Z will be more depolarized than in neuron Y. B. It won't be possible to discriminate which neuron's receptive field was stimulated at its center. C. The frequency of action potentials in the afferent pathway from neuron Y will be increased by excitatory interneurons projecting from the afferent pathways from neurons X and Z. D. The frequency of action potentials in neuron Y will be greater than that in neurons X and Z. E. The receptor potentials in all three neurons will achieve the same, average value.

d

5. Which best describes the process of "adaptation" in sensory receptors? A. Information from sensory receptors reaches the cerebral cortex and the person becomes aware of it. B. Conversion of the energy of a stimulus into a pattern of electrical activity. C. Persistence of the sensation of a limb even after it has been severed from the body. D. A decrease in receptor sensitivity despite continuation of a stimulus. E. A depolarization of receptive membrane that increase in magnitude as the stimulus intensity increases.

d

12. Which of the following statements regarding the precision of locating a somatic stimulus is FALSE? A. The precision is greater in areas of the body that have small, overlapping receptive fields than in areas with large, nonoverlapping receptive fields. B. The precision is greater in the lips and fingers than on the back. C. The precision is greater for the skin than for the internal organs. D. Lateral inhibition of parallel afferent pathways increases the precision of locating a stimulus. E. Convergence of afferent neurons onto common ascending pathways increases acuity.

e

17. Which of the following statements regarding pain pathways is FALSE? A. Substance P is an important neurotransmitter in specific pain pathways. B. Transmission of information in pain pathways may be inhibited by activation of neurons that synthesize opiate neurotransmitters. C. Synaptic activity in afferent neurons associated with pain receptors can be inhibited by axon-axon synapses with neurons from descending pathways. D. Afferents neurons that detect painful stimuli in the skin can converge onto common ascending pathways with neurons that detect painful stimuli in internal organs. E. Substance P is released by neurons descending from the brain, and it inhibits activation of ascending pain pathways.

e

4. What is the best definition of the "receptive field" of an afferent neuron? A. The number of interneurons with which the central process of the afferent neuron makes synaptic contact via divergence. B. The type of stimulus energy to which the afferent neuron is most sensitive. C. All of the interneuron cell bodies and dendrites onto which the afferent neuron synapses. D. The area of the cerebral cortex in which information from that afferent neuron is initially received. E. The area of the body that, when stimulated, leads to activity in that particular afferent neuron.

e

49. A "sensation" is any sensory information that reaches the brain. True False

f

52. The process by which sensory receptors change various forms of energy into electrical energy is called translation. True False

f

53. The greater the magnitude of the receptor potential generated by a stimulus, the greater the amplitude of the action potentials the receptor potential induces. True False

f

55. "Somatosensory" refers to the part of the cerebral cortex that receives synaptic input from specific ascending pathways originating only with receptors for touch. True False

f

57. Information about the location of a given stimulus on or in the body is conveyed by the same mechanisms that convey information about stimulus intensity. True False

f

58. The density of receptors in a receptive field is usually greatest in the periphery of the field. True False

f

59. In the somatosensory cortex, neuronal representation of body parts is proportional to the size of the body part. True False

f

60. The precision of locating a somatosensory stimulus is greater in areas of the body that have small, overlapping receptive fields than in areas with large, nonoverlapping fields. True False

t

61. The afferent pathways for pain differ from those for other somatic sensations in that they are highly influenced by with repeated exposure, and are significantly modulated by descending neuronal pathways. True False

t

64. In the phenomenon of phantom limb, a person can perceive tingling, touch, pressure, warmth, itch, and other sensations in a body part that has been lost by amputation or accident. True False

t

Chronic pain is A) only pathological. B) only treated by analgesic drugs. C) only the result of short-term changes in the nervous system. D) pathological and treated by analgesic drugs.

A

The gate control theory of pain modulation states that pain transmission can be blocked by A) cold stimulation of the A-delta fibers. B) mechanical stimulation of A-beta fibers. C) stimulation of C-fibers. D) tonic activity of the inhibitory neurons in the dorsal horn.

B

The tactile receptor whose nerve endings are surrounded by concentric connective tissue layers is the A) Ruffini corpuscle. B) Pacinian corpuscle. C) Meissner's corpuscle. D) Merkel disc. E) root hair plexus.

B

Visceral pain is poorly localized and can be perceived to originate from a region of the body that is different from it's actual location; this is called A) analgesia. B) adaptation. C) referred pain. D) tonic reception. E) latency.

C

Nociceptors are responsible for the perception of A) pain only. B) skin stretch only. C) itch only. D) pain and itch. E) pain and skin stretch.

D