Chapter 15 - Sensory Pathways and the Somatic Nervous System

Which structure conducts action potentials directly from a sensory receptor? A) 1 B) 2 C) 3 D) 5 E) 7

A) 1

Tactile receptors located in the reticular dermis that are tonic and show little if any adaptation are called A) Bulbous corpuscles. B) lamellar corpuscles. C) tactile (Meissner) corpuscles. D) tactile discs. E) root hair plexuses.

A) Bulbous corpuscles

Why is it that one cannot identify the location of internal organs, although joints and bone location can be identified? A) The internal organs have no proprioceptors like joints, bones, and muscles. B) Internal organs have no pain receptors. C) Although internal organs have some receptors, the information is not interpreted by the brain. D) Internal organs have no receptors of any kind. E) Sensory information from internal organs is processed by a different part of the brain than the joints, bones, and muscles.

A) The internal organs have no proprioceptors like joints, bones, and muscles

Which of the following statements is true about general senses? A) They are distributed all over the body. B) They are all mechanoreceptors. C) All receptors involved in general sensation consist of free nerve endings. D) They are located in sense organs. E) The reception of the stimulus occurs slowly with these receptors.

A) They are distributed all over the body.

Stimulation of a neuron that terminates in the superior region of the left postcentral gyrus would produce A) a sensation in the right leg. B) a sensation in the lips. C) a muscle twitch in the right leg. D) a muscle twitch in the lips. E) both sensations and muscle twitches in the right leg.

A) a sensation in the right leg.

Which motor pathway does not end in the spinal cord? A) corticobulbar tract B) corticospinal tract C) vestibulospinal tract D) tectospinal tract E) rubrospinal tract

A) corticobulbar tract

The pyramids on the ventral surface of the medulla oblongata are formed by fibers of the ________ tracts. A) corticospinal B) corticobulbar C) reticulospinal D) vestibulospinal E) tectospinal

A) corticospinal

Peripheral adaptation ________ the number of action potentials that reach the CNS. A) decreases B) increases C) stabilizes D) neutralizes E) amplifies

A) decreases

Which neuron delivers sensations to the CNS? A) first-order B) second-order C) third-order D) fourth-order E) sensory receptor

A) first-order

The general senses A) involve receptors that are relatively simple in structure. B) are located in specialized structures called sense organs. C) are localized to specific areas of the body. D) cannot generate action potentials. E) include taste and smell.

A) involve receptors that are relatively simple in structure

In order for a sensation to become a perception, A) it must be received by the somatosensory cortex. B) the individual must vocalize about it. C) it must arrive over fast-conducting nerve fibers. D) the other senses must be silent. E) it must be received by the pulvinar nucleus of the thalamus.

A) it must be received by the somatosensory cortex

The descending spinal tract that crosses to the opposite side of the body within the medulla oblongata is the ________ tract. A) lateral corticospinal B) anterior corticospinal C) rubrospinal D) reticulospinal E) vestibulospinal

A) lateral corticospinal

Endorphins can reduce perception of sensations initiated by A) nociceptors. B) mechanoreceptors. C) thermoreceptors. D) chemoreceptors. E) proprioceptors.

A) nociceptors

Pain is to ________ as cold is to ________. A) nociceptors; thermoreceptors B) baroreceptors; chemoreceptors C) baroreceptors; nociceptors D) chemoreceptors; nociceptors E) baroreceptors; thermoreceptors

A) nociceptors; thermoreceptors

For the last few weeks, you have had an odd sensation on your upper thigh. When you touch the naked skin, it feels very strange, like you are touching your skin through layers of cloth. The surrounding area feels normal. Your doctor thinks that this may be related to spinal nerve damage related to a herniated disc. The doctor calls this change in sensation A) paresthesia. B) anesthesia. C) hypesthesia. D) synesthesia. E) kinesthesia.

A) paresthesia.

Sensory neurons that adapt quickly are called ________ receptors. A) phasic B) tonic C) intracellular D) chemical-channel E) opioid

A) phasic

Two types of receptors that are least likely to adapt are the A) proprioceptors and nociceptors. B) free nerve endings and the root hair plexus. C) tactile discs and the free nerve endings. D) lamellar corpuscles and baroreceptors. E) chemoreceptors and baroreceptors.

A) proprioceptors and nociceptors

Gustatory receptors are sensitive to dissolved chemicals but insensitive to light. This is due to A) receptor specificity. B) accessory cells. C) the fact that they are interoceptors. D) receptor potentials. E) receptor speciation.

A) receptor specificity

Your uncle was just diagnosed with a heart attack. One of his major symptoms is left arm pain. You are not surprised because you are familiar with the phenomenon of ________ pain. A) referred B) phantom C) psychosomatic D) somatic E) neurogenic

A) referred

Ascending tracts in the spinal cord relay ________ information. A) sensory B) motor C) sensory and motor D) only somatic E) autonomic

A) sensory

The ________ nervous system carries impulses to skeletal muscles. A) somatic B) sympathetic C) parasympathetic D) afferent E) autonomic

A) somatic

A receptor that contains many mechanically-gated ion channels would function best as a A) tactile receptor. B) chemoreceptor. C) photoceptor. D) thermoreceptor. E) light receptor.

A) tactile receptor.

Identify the structure labeled "5." A) thalamus B) cerebral cortex C) primary motor cortex D) primary sensory cortex E) autonomic ganglion

A) thalamus

Sensory neurons that are always active are called ________ receptors. A) tonic B) static C) phasic D) isometric E) isotonic

A) tonic

The conversion of a sensory input to a change in membrane potential in the receptor is known as A) transduction. B) reception. C) effection. D) potential. E) stimulation.

A) transduction

The pyramidal system provides A) voluntary control over skeletal muscles. B) voluntary control over smooth muscles. C) involuntary control over skeletal muscles. D) involuntary control over smooth muscles. E) involuntary control over cardiac muscle.

A) voluntary control over skeletal muscles

A reduction in sensitivity in the presence of a constant stimulus is referred to as A) transduction. B) adaptation. C) negation. D) exhaustion. E) transformation.

B) adaptation

Mechanoreceptors that respond to changes in blood pressure are called A) nociceptors. B) baroreceptors. C) chemoreceptors. D) proprioceptors. E) thermoreceptors.

B) baroreceptors

Bladder fullness is to ________ as blood pH is to ________. A) nociceptors; thermoreceptors B) baroreceptors; chemoreceptors C) baroreceptors; nociceptors D) chemoreceptors; nociceptors E) baroreceptors; thermoreceptors

B) baroreceptors; chemoreceptors

General sense receptors are typically the A) dendrites of motor neurons. B) dendrites of sensory neurons. C) axons of motor neurons. D) axons of sensory neurons. E) cell bodies of sensory neurons.

B) dendrites of sensory neurons

The afferent neuron that carries the sensation and enters the CNS is a ________ neuron. A) receptor B) first-order C) second-order D) third-order E) fourth-order

B) first-order

A very large, fast-adapting tactile receptor that is composed of a single dendrite enclosed by concentric layers of collagen is a A) Bulbous corpuscle. B) lamellar (Pacinian) corpuscle. C) tactile (Meissner) corpuscle. D) tactile (Merkel) disc. E) root hair plexus.

B) lamellar (Pacinian) corpuscle.

Activity of neurons in the spinothalamic pathway may still send signals even if the first order sensory receptor does not receive a signal such as in amputation. This situation might cause A) referred pain. B) phantom limb pain. C) pain adaptation. D) paresthesia. E) anesthesia.

B) phantom limb pain.

The corticospinal pathway begins in which area of the brain? A) somatosensory cortex B) primary motor cortex C) midbrain D) vestibular nuclei E) red nuclei

B) primary motor cortex

Action potentials from receptors involved in general sensations are interpreted in the A) premotor cortex. B) primary sensory cortex. C) general interpretive area. D) mesencephalon. E) reticular activating system.

B) primary sensory cortex.

The ________ tract provides subconscious regulation of upper limb muscle tone and movement and is part of the ________ pathway. A) tectospinal; lateral B) rubrospinal; lateral C) reticulospinal; medial D) vestibulospinal; lateral E) corticobulbar; medial

B) rubrospinal; lateral

Sensory neurons synapse in the CNS with an interneuron known as a A) first-order neuron. B) second-order neuron. C) third-order neuron. D) motor neuron. E) efferent neuron.

B) second-order neuron

We can localize sensations that originate in different areas of the body because A) sensory neurons carry only one modality. B) sensory neurons from specific body regions project to specific cortical regions. C) incoming sensory information is first processed by the thalamus. D) different types of sensory receptors produce action potentials of different sizes and shapes. E) of the many types of tactile receptors.

B) sensory neurons from specific body regions project to specific cortical regions.

The term general senses refers to sensitivity to all of the following, except A) temperature. B) taste. C) touch. D) vibration. E) pain.

B) taste.

The medial pathway that controls involuntary movements of head, neck, and arm position in response to sudden visual and auditory stimuli is the ________ tract. A) lateral corticospinal B) tectospinal C) rubrospinal D) reticulospinal E) vestibulospinal

B) tectospinal

Free nerve endings detect which stimulus/stimuli? A) chemical B) temperature, pain, stretch and touch C) pain only D) stretch E) deep pressure

B) temperature, pain, stretch and touch

Upper motor neurons of the corticospinal tract synapse with neurons in A) autonomic ganglia. B) the anterior gray horns of the spinal cord. C) the spinothalamic tract. D) the lateral gray horns of the spinal cord. E) the dorsal root ganglia.

B) the anterior gray horns of the spinal cord

The conversion of the stimulus into an action potential to be interpreted by the brain is called A) transformation. B) transduction. C) translation. D) transcription. E) transpotential.

B) transduction

Descending (motor) pathways always involve at least ________ motor neuron(s). A) one B) two C) three D) four E) spinal

B) two

________ are receptors in the aorta that monitor the blood pressure. A) Chemoreceptors B) Nociceptors C) Baroreceptors D) Proprioceptors E) Hair cells

C) Baroreceptors

The sensory receptors, neurons and pathways make up the ________ division of the nervous system. A) voluntary B) efferent C) afferent D) involuntary E) somatic

C) afferent

Where in the spinal cord is the structure labeled "2" located? A) anterior gray horns B) dorsal root ganglion C) anterior white column D) anterior median fissure E) posterior white column

C) anterior white column

All of the following are true of fast pain sensations except that they A) are carried by type A fibers. B) reach the CNS quickly. C) are interpreted by the pre-frontal cortex. D) receive conscious attention. E) often trigger somatic reflexes.

C) are interpreted by the pre-frontal cortex

In motor pathways, the only portion of the pathway that is outside of the CNS is the A) lower motor neuron. B) upper motor neuron. C) axon of the lower motor neuron. D) axon of the upper motor neuron. E) interneuron.

C) axon of the lower motor neuron.

Which areas of the brain monitor and adjust activities of the motor pathways? A) basal nuclei B) cerebellum C) basal nuclei and cerebellum D) midbrain E) pons

C) basal nuclei and cerebellum

Chemoreceptors of the general senses do not send information to the primary sensory cortex but instead send information to the ________ to control autonomic function. A) cerebellum B) cerebrum C) brain stem D) spinal cord E) corpus callosum

C) brain stem

Sensations of burning or aching pain A) are carried by type A fibers. B) reach the CNS quickly. C) cause a generalized activation of the reticular formation and the thalamus. D) are well localized. E) are fast adapting.

C) cause a generalized activation of the reticular formation and the thalamus.

Identify the neuron labeled "1." A) lower motor neuron B) upper motor neuron C) first-order neuron D) second-order neuron E) ganglionic neuron

C) first-order neuron

Central adaptation refers to A) the decline in activity of peripheral receptors when stimulated. B) a characteristic of phasic receptors. C) inhibition of nuclei located along a sensory pathway. D) increases in conscious perception of a sensory stimulus. E) a change in motor receptivity of a neuron.

C) inhibition of nuclei located along a sensory pathway.

What loss would result from cutting through the medial lemniscus on the right side? A) loss of pain sensation on the left side of the body B) loss of pain sensation on the right side of the body C) loss of fine touch sensation on the left side of the body D) loss of fine touch sensation on the right side of the body E) complete hemiplegia (paralysis) on the left side of the body

C) loss of fine touch sensation on the left side of the body

The area of the motor cortex that is devoted to a particular region of the body is proportional to the A) size of the body area. B) distance of the body area from the brain. C) number of motor units in that region. D) number of sensory receptors in the area of the body. E) size of the nerves that serve the area of the body.

C) number of motor units in that region

Which ascending tract carries the sensations for fine touch and vibration? A) corticobulbar B) corticospinal C) posterior (dorsal) column D) spinothalamic E) spinocerebellar

C) posterior (dorsal) column

The third-order neuron in this pathway synapses in what structure labeled "7"? A) cerebellum B) thalamus C) primary sensory cortex D) pons E) medulla oblongata

C) primary sensory cortex

You cannot tell when your small intestines shift position as food enters because you do not have any ________ there. A) chemoreceptors B) nociceptors C) proprioceptors D) thermoreceptors E) photoreceptors

C) proprioceptors

The basal nuclei A) initiate conscious motor activity. B) activate spinal reflexes. C) provide the background patterns of movement involved in voluntary motor activities. D) exert direct control over lower motor neurons. E) act as gatekeepers, filtering out unnecessary sensorimotor activity.

C) provide the background patterns of movement involved in voluntary motor activities

The neurons of the primary motor cortex are ________ cells. A) neuroglial B) dendritic C) pyramidal D) cortical E) astrocyte

C) pyramidal

The spinal tract that normally plays a role in the subconscious regulation of the muscles of the arms is the ________ tract. A) lateral corticospinal B) anterior corticospinal C) rubrospinal D) reticulospinal E) vestibulospinal

C) rubrospinal

The sense of proprioception passes along the ________ pathway. A) rubriocerebellar B) corticospinal C) spinocerebellar D) decussation pathways E) ganglion

C) spinocerebellar

A tactile receptor composed of highly coiled dendrites that are surrounded by modified Schwann cells and a fibrous capsule is a A) lamellar corpuscle. B) Bulbous corpuscle. C) tactile (Meissner) corpuscle. D) tactile (Merkel) disc. E) root hair plexus.

C) tactile (Meissner) corpuscle.

All of the following pathways require third-order neurons synapsing in the thalamus except A) the lateral spinothalamic tract. B) the anterior spinothalamic tract. C) the anterior and posterior spinocerebellar tracts. D) the gracile fasciculus. E) the cuneate fasciculus.

C) the anterior and posterior spinocerebellar tracts

Chemoreceptors are located in all of the following except A) carotid bodies. B) aortic bodies. C) the skin. D) the organs of taste. E) the organs of smell.

C) the skin.

Sensory encoding of the perceived location of a stimulus depends on A) the frequency of action potentials. B) which labeled line is active. C) the specific location of the cortical neuron that is stimulated. D) the specific sensitivity of the peripheral receptor. E) the number of receptors stimulated.

C) the specific location of the cortical neuron that is stimulated

In the spinothalamic pathway, the sensory neuron that synapses with a neuron in the cerebral cortex is called the ________ neuron. A) first-order B) second-order C) third-order D) fourth-order E) receptive

C) third-order

The heart muscle is a ________ effector. A) somatic B) sympathetic C) visceral D) afferent E) higher-order

C) visceral

Which of the following is true of all the sensory pathways? A) They all have third-order neurons. B) They all synapse in the thalamus. C) They all synapse in the cerebellum. D) They all enter through dorsal roots. E) Axons in each pathway decussate.

D) They all enter through dorsal roots.

Which of the following is a progressive, degenerative disorder that affects upper and lower motor neurons causing skeletal muscle atrophy? A) cerebral palsy B) stroke C) paralysis D) amyotrophic lateral sclerosis E) multiple sclerosis

D) amyotrophic lateral sclerosis

Identify the axon labeled "3." A) axon of a lower motor neuron B) axon of a upper motor neuron C) axon of a first-order neuron D) axon of a second-order neuron E) axon of a ganglionic neuron

D) axon of a second-order neuron

Based on the motor homunculus, which of the following body regions has the fewest number of motor units involved? A) tongue B) face C) hands D) back trunk

D) back trunk

If a friend is talking about someone she knows who lost his special senses, you would correct her when you hear her mention ________ because it is not a special sense. A) smell B) sight C) balance D) cold E) hearing

D) cold

Identify the type of information that travels along the structure labeled "2." A) motor commands to skeletal muscles B) proprioception to the cerebral cortex C) fine touch to the cerebral cortex D) crude touch and pressure sensations E) visceral motor commands to smooth muscle

D) crude touch and pressure sensations

Which of the following is/are sometimes called "prickling pain"? A) mechanical damage B) proprioception C) extremes of temperature D) fast pain E) fast and slow pain

D) fast pain

A ________ potential is a depolarization of a sensory dendrite that can lead to an afferent nerve impulse if strong enough. A) resting B) refractory C) postsynaptic D) generator E) presynaptic

D) generator

The spinal tract that relays information concerning pain and temperature to the CNS is the A) gracile fasciculus. B) cuneate fasciculus. C) posterior spinocerebellar. D) lateral spinothalamic. E) anterior spinothalamic.

D) lateral spinothalamic

Axons of the corticobulbar tract terminate in the A) sensory neurons. B) somatic motor neurons in the spinal cord. C) autonomic motor neurons in the spinal cord. D) motor nuclei of cranial nerves. E) nuclei in the thalamus.

D) motor nuclei of cranial nerves

A sensory receptor characterized peripherally as a free nerve ending which centrally uses glutamate and/or substance P as neurotransmitters would most likely be a A) chemoreceptor. B) mechanoreceptor. C) thermoreceptor. D) nociceptor. E) free receptor.

D) nociceptor

Your brain is not constantly bombarded with signals telling it that you are wearing socks. This is because the touch receptors around your ankle are A) tonic receptors. B) tonic receptors and slow-adapting. C) phasic receptors and slow-adapting. D) phasic receptors and fast-adapting. E) nociceptors.

D) phasic receptors and fast-adapting

Which of the following is a property of thermoreceptors? A) involves specialized receptors B) monitor heat stimuli, not cold C) found in skin only D) project to reticular formation E) cold receptors are less numerous than warm receptors

D) project to reticular formation

Receptors that monitor the position of joints belong to the category called A) nociceptors. B) chemoreceptors. C) baroreceptors. D) proprioceptors. E) thermoreceptors.

D) proprioceptors

The corticospinal system is often referred to as the A) red nucleus. B) reticular formation. C) spinothalamic tracts. D) pyramidal system. E) medullary centers.

D) pyramidal system

Using the two-point discrimination test you can fairly accurately determine whether you have been touched with one point or two because of the density of the A) effectors. B) perception. C) labeled line. D) receptor fields. E) action potential.

D) receptor fields

The rubrospinal tracts originate in the A) primary motor cortex. B) vestibular nuclei. C) thalamus. D) red nuclei. E) reticular formation.

D) red nuclei

Each of the following is an ascending tract in the spinal cord except the A) gracile fasciculus. B) cuneate fasciculus. C) posterior spinocerebellar. D) reticulospinal tract. E) anterior spinothalamic.

D) reticulospinal tract

A highly sensitive tactile receptor composed of dendritic processes of a single myelinated fiber that makes contact with specialized cells of the stratum basale is a A) lamellar corpuscle. B) tactile (Meissner) corpuscle. C) Bulbous corpuscle. D) tactile (Merkel) disc. E) root hair plexus.

D) tactile (Merkel) disc

Sensory information from all parts of the body is routed to A) the prefrontal cortex. B) the cerebellum. C) the primary motor cortex. D) the somatosensory cortex. E) Broca's area.

D) the somatosensory cortex

Thalamic neurons that project to the primary sensory cortex are ________ neurons. A) receptor B) first-order C) second-order D) third-order E) fourth-order

D) third-order

We are constantly bombarded by a variety of stimuli inside and outside of our bodies. Why are we not overwhelmed by sensory information? A) We do not have receptors for most stimuli. B) Stimuli are blocked from the receptors by our immune systems. C) Most stimuli are external to our bodies and we have very few exteroceptors on the outside of the body. D) A particular receptor type can have different sensitivities to different stimuli. E) A very tiny percentage of incoming sensory information is received by the cerebral cortex.

E) A very tiny percentage of incoming sensory information is received by the cerebral cortex.

The spinal tract that relays information concerning crude touch and pressure to the CNS is the A) gracile fasciculus. B) cuneate fasciculus. C) posterior spinocerebellar. D) lateral spinothalamic. E) anterior spinothalamic.

E) anterior spinothalamic.

Receptors in your stomach that determine when food enters because the pH changes would be classified as A) mechanoreceptors. B) nociceptors. C) proprioceptors. D) baroreceptors. E) chemoreceptors.

E) chemoreceptors.

The motor homunculus shows larger structures in areas of the body that A) have more surface area. B) have more sensory receptors. C) have bigger skeletal muscles. D) are highly sensitive. E) have more motor units.

E) have more motor units.

The link between peripheral receptor and cortical neuron is called a(n) A) efferent pathway. B) spinocortical line. C) sympathetic chain. D) adaptation pathway. E) labeled line.

E) labeled line.

Which is an example of a slow-adapting receptor? A) phasic B) touch C) smell D) temperature E) pain

E) pain

A mechanoreceptor in the papillary layer of the dermis that responds to fine touch is a A) tactile (Merkel) disc. B) root hair plexus. C) free nerve ending. D) Bulbous corpuscle. E) tactile (Meissner) corpuscle.

E) tactile (Meissner) corpuscle

All of the following can contribute to receptor specificity except A) the structure of the receptor cell. B) characteristics of the receptor cell membrane. C) accessory cells that function with the receptor. D) accessory structures and tissues that shield the receptors from other stimuli. E) the metabolism of the receptor cell.

E) the metabolism of the receptor cell

A receptor potential may cause all of the following responses except A) increase neurotransmitter release. B) decrease neurotransmitter release. C) cause hyperpolarization. D) cause depolarization. E) turning off the original stimulus.

E) turning off the original stimulus.

The spinal tract that unconsciously maintains balance and muscle tone is the ________ tract. A) lateral corticospinal B) anterior corticospinal C) rubrospinal D) reticulospinal E) vestibulospinal

E) vestibulospinal