Deck 6: A--The Peripheral Nervous System: Afferent Division; Special Senses

Question 1

Endorphins and enkephalins

A) are endogenous morphine-like substances
B) are important in the body's natural analgesic system
C) stimulate the release of substance P by binding with opiate receptors
D) are endogenous morphine-like substances, important in the body's natural analgesic system
E) all of these

Answer 1

D

Question 2

Afferent input that does not reach the conscious level is

A) somatic
B) proprioceptive
C) somethetic
D) a special sense
E) visceral

Answer 2

E

Question 3

Receptors

A) may be either a specialized ending of an afferent neuron or a special cell closely associated with the peripheral ending of an afferent neuron
B) exist that are specific for every modality in the environment
C) when stimulated enough may cause Na⁺ channels in the afferent neuron membrane to open
D) exist that are specific for every modality in the environment, and when stimulated enough may cause Na⁺ channels in the afferent neuron membrane to open.
E) all of these

Answer 3

D

Question 4

Select the incorrect association:

A) chemoreceptor/oxygen concentration
B) mechanoreceptor/skeletal muscle stretch
C) nociceptor/solute concentration
D) photoreceptor/light
E) thermoreceptor/heat and cold

Question 5

Which is characteristic of fast pain?

A) poorly localized
B) occurs upon stimulation of polymodal nociceptors
C) impulses carried along myelinated fibers
D) persists for a long period of time
E) none of these

Question 6

In somatosensory pathways, first-order neurons usually synapse with second-order neurons in the

A) dorsal root ganglia
B) medulla oblongata
C) spinal cord
D) dorsal root ganglia and medulla oblongata
E) medulla oblongata and spinal cord

Question 7

Pacinian corpuscles

A) adapt as a result of the physical features of the receptor
B) detect temperature
C) are tonic receptors
D) do not display an "off-response"
E) measure the degree of joint flexion

Question 8

Identify the true statement(s) about sensory receptors:

A) The larger the receptor potential, the greater the frequency of action potentials initiated in the afferent neuron.
B) Tonic receptors often exhibit an "off-response."
C) Phasic receptors are important in situations where maintained information about a stimulus is valuable.
D) Receptor adaptation results from nerve fatigue.
E) Receptors are part of efferent neurons.

Question 9

Receptors

A) respond to various physical or chemical changes in their environment
B) change other forms of energy into electrical energy
C) respond more readily to their adequate stimulus
D) are found at the peripheral endings of afferent neurons
E) all of these

Question 10

Receptors

A) generate action potentials in afferent fibers in response to stimuli
B) change other forms of energy into electrical energy
C) are located in the dorsal root ganglion
D) generate action potentials in afferent fibers in response to stimuli and change other forms of energy into electrical energy
E) all of these

Question 11

Conscious interpretation of external stimuli

A) is sensation
B) rarely occurs
C) is perception
D) is processed in the diencephalon
E) none of these

Question 12

The smaller the receptive fields in a region, the

A) greater the density of receptors in the region
B) greater the acuity in the region
C) more cortical space allotted for sensory reception from the region
D) all of these
E) greater the density of receptors in the region and greater the acuity in the region

Question 13

Receptor potentials

A) are always depolarizations
B) are graded potentials
C) have refractory periods
D) are always depolarizations and are graded potentials
E) none of these

Question 14

Polymodal nociceptors

A) respond only to mechanical damage such as cutting, crushing, or pinching
B) transmit impulses along A-delta fibers
C) activate the slow pain pathway
D) release prostaglandins
E) none of these

Question 15

Which of the following receptors are rapidly adapting?

A) proprioceptors
B) nociceptors
C) Pacinian corpuscles
D) muscle receptors
E) all of these

Question 16

Coding of sensory information may result from

A) intensity of the stimuli
B) location of the stimuli
C) stimulus modality
D) all of these
E) none of these

Question 17

Tonic receptors

A) adapt rapidly
B) frequently exhibit an "off-response"
C) can measure the degree of joint flexion
D) all of these
E) none of these

Question 18

The slow pain pathway is activated by

A) stimulation of mechanical or thermal nociceptors
B) stimulation of polymodal nociceptors
C) bradykinin
D) stimulation of mechanical or thermal nociceptors and bradykinin
E) stimulation of polymodal nociceptors and bradykinin

Question 19

The conversion of stimuli into neuron potentials

A) requires an adequate level of stimulus
B) is called transduction
C) stems from generation of receptor potentials
D) all of these
E) none of these

Question 20

Phasic receptors

A) exhibit an "off-response"
B) signal a change in stimulus intensity
C) are rapidly adapting receptors
D) all of these
E) none of these

Question 21

During accommodation for near vision, the

A) ciliary muscle moves away from the lens
B) lens becomes stronger
C) suspensory ligaments become more taut
D) ciliary muscle moves away from the lens and the lens becomes stronger
E) ciliary muscle moves away from the lens and the suspensory ligaments become more taut

Question 22

In order for accommodation to occur:

A) The shape of the cornea must be changed.
B) The shape of the lens must be changed.
C) The ciliary muscle is relaxed for near vision.
D) The ciliary muscle is contracted for distant vision.
E) All of these, except the shape of the cornea must be changed.

Question 23

The blind spot

A) is the point on the retina at which the optic nerve leaves and blood vessels pass through
B) contains special photoreceptors that make only melanospin, which is not used for vision
C) is in the exact center of the retina
D) all of these
E) is the point on the retina at which the optic nerve leaves and blood vessels pass through and is in the exact center of the retina

Question 24

Rhodopsin

A) is the photopigment in the red cones
B) consists of an opsin and retinal
C) is most highly concentrated in the fovea
D) is slowly broken down in the absence of light
E) contains a derivative of vitamin B₁₂

Question 25

Natural analgesia occurs when:

A) Endogenous opiates bind to P-substance.
B) Endogenous opiates bind to receptors on afferent pain fibers.
C) The periaquaductal gray matter is stimulated.
D) Endogenous opiates bind to P-substance and to receptors on afferent pain fibers.
E) Endogenous opiates bind to receptors on afferent pain fibers and the periaquaductal gray matter is stimulated.

Question 26

Which neuromodulator is not capable of binding to opiate receptors in the analgesic pathways?

A) bradykinin
B) dynorphin
C) endogenous opiates
D) endorphins
E) enkephalins

Question 27

The retina

A) is the middle layer of the eye
B) contains the photoreceptors
C) becomes specialized anteriorly to form the cornea
D) secretes the aqueous humor
E) none of these

Question 28

The lens of the eye

A) has convex surfaces
B) is stronger when it is flatter
C) contributes most extensively to the eye's total refractive ability
D) has convex surfaces and is stronger when it is flatter
E) all of these

Question 29

The first structure to intercept light as it enters the eye is the

A) aqueous humor
B) cornea
C) lens
D) retina
E) vitreous humor

Question 30

How is glutamate important to pain pathways?

A) binds to AMPA receptors on dorsal horn cells
B) results in hypersensitivity of damaged tissue
C) causes P-substance release
D) binds to AMPA receptors on dorsal horn cells and results in hypersensitivity of damaged tissue
E) results in hypersensitivity of damaged tissue and causes P-substance release

Question 31

As light passes from one medium to a medium of a different density, it

A) is refracted
B) bends at specific angles
C) changes wavelengths
D) is refracted and bends at specific angles
E) none of these

Question 32

Which of the following structures contributes the most to the total refractive ability of the eye?

A) lens
B) cornea
C) ciliary muscle
D) retina
E) iris

Question 33

Which of the following structures normally controls the amount of light entering the eye?

A) ciliary muscle
B) suspensory ligaments
C) iris
D) cornea
E) lens

Question 34

The fovea

A) is located in the exact center of the retina
B) contains a greater abundance of rods than cones
C) is the point on the retina at which the optic nerve leaves and blood vessels pass through
D) all of these
E) is located in the exact center of the retina and is the point on the retina at which the optic nerve leaves and blood vessels pass through

Question 35

In hyperopia:

A) The eyeball is too short or the lens is too weak.
B) A near object is focused behind the retina, even with accommodation.
C) A far source of light is focused ahead of the retina.
D) The eyeball is too short or the lens is too weak, and a near object is focused behind the retina, even with accommodation.
E) The eyeball is too short or the lens is too weak, and a far source of light is focused ahead of the retina.

Question 36

The circular muscle of the iris

A) contracts in response to bright light to produce pupillary constriction
B) is innervated by the parasympathetic nervous system
C) contracts to slacken the suspensory ligaments and to increase the strength of the lens during accommodation
D) contracts in response to bright light to produce pupillary constriction and is innervated by the parasympathetic nervous system
E) all of these

Question 37

Select the incorrect statement about slow pain.

A) It is carried by large, myelinated A-delta fibers.
B) It is poorly localized.
C) It occurs by the stimulation of polymodal nociceptors.
D) It occurs for a longer time than fast pain.
E) It produces a dull, aching, burning sensation.

Question 38

The choroid

A) contains rods and cones
B) is a fluid within the eye
C) is also known as the blind spot
D) is the middle layer of the eye
E) refracts light rays

Question 39

Which of the following helps reduce internal reflection (scattering of light within the eye)?

A) sclera
B) choroid
C) blind spot
D) lens
E) iris

Question 40

Which of the following statements about myopia is correct?

A) The curvature of the lens is uneven.
B) A near source of light is focused on the retina without accommodation.
C) A convex lens is used to correct the condition.
D) The images from the two eyes are not fused within the cortex.
E) There is increased intraocular pressure.

Question 41

Incoming visual information is relayed to the appropriate cortical tissue by the

A) ganglion cells
B) lateral geniculate nuclei
C) thalamus
D) ganglion cells and thalamus
E) lateral geniculate nuclei and thalamus

Question 42

In the visual pathway:

A) The fibers from the medial halves of both retinas cross at the optic chiasm.
B) The optic nerve carries information from the lateral half of one retina and the medial half of the other retina.
C) The optic nerve carries information from both the lateral half and the medial half of the retina of the same eye.
D) The fibers from the medial halves of both retinas cross at the optic chiasm, and the optic nerve carries information from the lateral half of one retina and the medial half of the other retina.
E) The fibers from the medial halves of both retinas cross at the optic chiasm, and the optic nerve carries information from both the lateral half and the medial half of the retina of the same eye.

Question 43

Color vision

A) is perceived in the optic chiasma but is interpreted in the primary visual cortex
B) depends on the three cone types' various ratios of stimulation in response to different wavelengths of light
C) is usually lost in vitamin A deficiency
D) depends on activation of a specific cone for each visible color
E) is made possible by convergence within the cone pathways

Question 44

Which of the following does not occur in a photoreceptor during exposure to light?

A) membrane hyperpolarization
B) closure of Na⁺ channels in the outer segment
C) increased transmitter release from the synaptic terminal
D) decrease in cyclic GMP in the outer segment
E) closure of Ca²⁺ channels in the synaptic terminal

Question 45

Vitamin A deficiency causes

A) poor night vision
B) poor color vision
C) color blindness
D) presbyopia
E) poor night vision and presbyopia

Question 46

Cones have higher acuity than rods because

A) Cones respond more to long wavelengths of light.
B) There are three types of cones.
C) There is little convergence in the cone pathways within the retina.
D) There are more cones than rods.
E) The photopigment in the cones breaks down more rapidly than the photopigment in rods.

Question 47

Presbyopia is characterized by

A) the lack of a particular cone type
B) pronounced visual difficulty in the early teenage years
C) a reduction in accommodative ability as a result of a loss of lens elasticity
D) retinal damage
E) excessive refractive power in the lens system of the eye

Question 48

Which of the following statements concerning cones is not correct?

A) Cones are used for day vision.
B) Cones are very sensitive to light.
C) Cones exhibit high acuity.
D) Cones are concentrated in the fovea.
E) Cones provide color vision.

Question 49

The three types of cones are

A) black, red, and white
B) blue, green, and red
C) blue, green, and white
D) green, orange, and yellow
E) orange, yellow, and white

Question 50

Which of the following is the proper sequence of retinal processing?

A) rods and cones¾ganglion cells¾bipolar cells
B) rods and cones¾bipolar cells¾ganglion cells
C) ganglion cells¾bipolar cells¾rods and cones
D) ganglion cells¾rods and cones¾bipolar cells
E) bipolar cells¾ganglion cells¾rods and cones

Question 51

During dark adaptation:

A) Photopigments are gradually regenerated.
B) Rhodopsin is rapidly broken down.
C) The sensitivity of the photoreceptors is reduced so that the image appears dim.
D) The bipolar cells are no longer inhibited.
E) Photopigments are gradually regenerated and the sensitivity of the photoreceptors is reduced so that the image appears dim.

Question 52

What condition is caused by uneven curvatures in the lens?

A) astigmatism
B) myopia
C) presbyopia
D) hyperopia
E) none of these

Question 53

The middle layer of the retina contains

A) bipolar neurons
B) convex cells
C) ganglion cells
D) hair cells
E) rods and cones

Question 54

The optic track carries information from

A) the lateral half of the retina on the same side and the medial half of the retina on the opposite side
B) the lateral halves of both retinas
C) the medial halves of both retinas
D) the lateral half of the retina on the opposite side and the medial half of the retina on the same side
E) both the lateral and medial halves of the retina on the same side

Question 55

Cones

A) are most abundant in the periphery of the retina
B) are more numerous than rods
C) have high sensitivity to light
D) are responsible for color vision
E) more than one of these

Question 56

Rods

A) are more sensitive to light than cones
B) have low acuity
C) provide vision in shades of gray
D) have low acuity and provide vision in shades of gray
E) all of these

Question 57

Which one of the following is an anterior specialization of the choroid layer?

A) aqueous humor
B) ciliary body
C) cornea
D) lens
E) retina

Question 58

In light adaptation:

A) Phototransduction does not occur in the retinal regions outside of the fovea.
B) Rhodopsin levels decrease in rods.
C) The iris' circular muscle relaxes.
D) Phototransduction does not occur in the retinal regions outside of the fovea, and rhodopsin levels decrease in rods.
E) Rhodopsin levels decrease in rods, and the iris' circular muscle relaxes.

Question 59

Which of the following activities occurs in the presence of light within the phototransduction pathway?

A) Ganglion cells stimulate bipolar cells.
B) cGMP levels increase within photoreceptors.
C) Bipolar cells produce graded potentials.
D) Sodium channels open in photoreceptors.
E) None of these.

Question 60

Which structure(s) is/are associated with hearing?

A) ampulla
B) cochlea
C) cupula
D) cristae
E) saccule

Question 61

Transmission of sound through the middle ear results in

A) amplification of the pressure vibrations
B) stimulation of middle ear receptor cells
C) opening of the eustachian tube
D) increased firing rate in sensory axons associated with the tympanic membrane
E) none of these

Question 62

The oval window

A) attaches to the malleus
B) transfers the sound wave from the vestibule to the cochlea
C) is reflexively tightened in response to loud sounds to diminish transmission of these sounds to the inner ear
D) attaches to the malleus and is reflexively tightened in response to loud sounds to diminish transmission of these sounds to the inner ear
E) none of these

Question 63

Which of the following abnormalities could give rise to sensorineural deafness?

A) rupture of the tympanic membrane
B) disease or injury in the organ of Corti
C) restriction of ossicular movement because of adhesions between the bones
D) damage to the occipital lobes of the cortex
E) presbyopia

Question 64

The hair cells for hearing are located in the

A) ampullae
B) eustachian tube
C) scala media
D) utricle
E) vestibule

Question 65

Deflection of the basilar membrane

A) activates receptors of the scala tympani
B) occurs in response to fluid movements in the utricle
C) results in vibrations in endolymph
D) does not result from vibrations in perilymph
E) all of these

Question 66

In which structure do sound waves first pass?

A) cochlear duct
B) scala media
C) scala tympani
D) scala vestibuli
E) helicotrema

Question 67

Which type of sensory input is not integrated into the sense of equilibrium?

A) cutaneous
B) proprioceptive
C) vestibular
D) visual
E) visceral

Question 68

Which one of the following is not involved in sending the vibrational signal to the inner ear?

A) external auditory meatus
B) eustachian tube
C) malleus
D) stapes
E) tympanum

Question 69

The vibrational stimulus normally passes through the middle ear ossicles in the order:

A) incus to the malleus to the stapes
B) incus to the stapes to the incus
C) malleus to the incus to the stapes
D) malleus to the stapes to the incus
E) stapes to the malleus to the incus

Question 70

The semicircular canals

A) detect the position of the head relative to gravity
B) detect rotational or angular acceleration of the head
C) contain otoliths
D) detect the position of the head relative to gravity and contain otoliths
E) detect rotational or angular acceleration of the head and contain otoliths

Question 71

Select the structure that is not found inside the cochlear duct.

A) basilar membrane
B) endolymph
C) oval window
D) organ of Corti
E) tectorial membrane

Question 72

In response to movement of the oval window,

A) Pressure waves occur in the scala vestibuli.
B) A portion of the basilar membrane vibrates.
C) Certain hair cell receptors in the organ of Corti become excited.
D) The round window is displaced.
E) All of these.

Question 73

Which statement is false?

A) Sound waves are produced by a disturbance pattern in air molecules.
B) Sound waves gradually dissipate as they travel from the original sound source.
C) Long sound waves vibrate more hair cells near the oval window than near the helicotrema.
D) A sound at 60 decibels will always be louder than a sound at 50 cycles per second.
E) Sound waves vibrate perilymph before they vibrate endolymph.

Question 74

The ossicular system of the ear

A) serves to keep the pressure on the two sides of the tympanic membrane equal
B) increases the pressure of vibration as it transfers the sound wave from air in the outer ear to fluid in the inner ear
C) assists in determining whether a sound comes from the front or rear
D) is part of the vestibular apparatus
E) is in direct contact with the tympanic membrane and the round window

Question 75

The pitch of a sound

A) is determined by the frequency of vibrations of air molecules
B) depends on the amplitude of the waves
C) is measured in units called decibels
D) determines a sound's loudness
E) all of these

Question 76

High- and low-frequency sounds are discriminated chiefly by

A) low frequencies producing stronger vibrations
B) high frequencies producing larger action potentials
C) the middle ear bones vibrating more vigorously for low frequencies
D) low frequencies deflecting the basilar membrane at a greater distance from the oval window
E) low frequencies setting up fluid vibrations in the perilymph

Question 77

Fluid movement in the cochlea causes

A) displacement of the round window, which dissipates pressure
B) deflection of the cupula
C) the hairs of the receptor cells of the organ of Corti to be bent as they are moved in relation to the otoliths
D) displacement of the round window, which dissipates pressure, and the hairs of the receptor cells of the organ of Corti to be bent as they are moved in relation to the otoliths
E) all of these

Question 78

The human ear is most sensitive to sound frequencies within the range of

A) 0-20,000 cycles per second
B) 20-20,000 cycles per second
C) 10-100,000 cycles per second
D) 100-15,000 cycles per second
E) 1,000-4,000 cycles per second

Question 79

The tympanic membrane

A) vibrates when struck by the incus
B) contains the organ of Corti
C) produces ear wax
D) is connected to the stapes
E) none of these

Question 80

Actual conversion of sound vibrations to nerve impulses occurs in the

A) eardrum
B) ossicular system
C) eustachian tube
D) cochlea
E) oval window