Deck 6: The Peripheral Nervous System: Afferent Division Special Senses

Question 1

Afferent input that does not reach the conscious level is

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

Answer 1

E

Question 2

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)exhibit both a and b characteristics
E)exhibit both a and c characteristics

Answer 2

D

Question 3

Receptors

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

Answer 3

E

Question 4

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 5

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 6

Which of the following receptors are rapidly adapting?

A)proprioceptors
B)nociceptors
C)Pacinian corpuscles
D)muscle receptors
E)All of the above

Question 7

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

A)dorsal root ganglia or basal nuclei
B)medulla oblongata or thalamus
C)spinal cord or cerebellum
D)dorsal root ganglia or medulla oblongata
E)spinal cord or medulla oblongata

Question 8

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)produces burning sensation

Question 9

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)do not react in any of the above ways

Question 10

Phasic receptors

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

Question 11

Identify the true statement(s) about receptors:

A)They may be a specialized ending of an afferent neuron
B)They exist that are specific for every modality in the environment
C)When stimulated enough may cause Na+ channels in the afferent neuron to open
D)They may be cells closely associated with the peripheral endings of afferent neurons
E)All of the above are true.

Question 12

Receptor potentials

A)are always depolarizations
B)are graded potentials
C)have refractory periods
D)are always action potentials
E)are not any of the above

Question 13

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 14

The smaller the receptive fields in a region,

A)the lower the density of receptors in the region
B)the lower the acuity in the region
C)the more likely of feeling two separate stimuli occurring close together on the skin
D)all of the above will be true
E)only a and b will be true

Question 15

Receptors

A)experience action potentials in response to stimuli
B)receive signals from the afferent division of the PNS
C)can initiate action potentials in afferent neurons
D)sends efferent information to the CNS
E)perform all of the above

Question 16

The slow pain pathway is activated by

A)stimulation of mechanical or thermal nociceptors
B)stimulation of polymodal nociceptors
C)bradykinin
D)only a and c
E)only b and c

Question 17

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 18

Tonic receptors

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

Question 19

Conscious interpretation of external stimuli

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

Question 20

Coding of sensory information may result from

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

Question 21

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 22

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 23

Accommodation in the eye requires

A)the shape of the cornea to change
B)the shape of the lens to change
C)the ciliary muscle to be relaxed for near vision
D)the ciliary muscle to be contracted for distant vision
E)b, c, and d

Question 24

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 25

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 26

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)exhibits both a and b
E)exhibits none of the above

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)is not characterized by any of the above\

Question 28

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)exhibits all of the above
E)exhibits only a and b

Question 29

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 30

Natural analgesia occurs when

A)endogenous opiates bind to P-substance
B)endogenous opiates bind to nociceptors in the spinal cord
C)the periaquaductal gray matter stimulates afferent pain fibers in the spinal cord
D)endogenous opiates bind to excitatory interneurons in the dorsal horns
E)periaquaductal gray matter causes interneurons to release endogenous opiates that bind to receptors on afferent pain fibers

Question 31

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 32

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)both a and b are the cause
E)both a and c are the cause

Question 33

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)exhibits all of the above
E)exhibits only a and c

Question 34

During accommodation for near vision,

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

Question 35

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)is made of vitreous humor
E)has all of the characteristics above

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 loosen the suspensory ligaments and to increase the strength of the lens during accommodation
D)is characterized by a and b
E)is characterized by b and c

Question 37

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)Both a and b
E)Both a and c

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

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

Question 40

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 41

Identify the incorrect statement about cones in the retina:

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

Question 42

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 cones breaks down more rapidly than the photopigment in rods.

Question 43

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)both a and b occur
E)both b and c occur

Question 44

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)exhibit more than one of the above characteristics

Question 45

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

A)rods and cones-ganglion cells-bipolar cells
B)rods and cones-bipolar cells-ganglion cells
C)ganglion cells-bipolar cells-rods and cones
D)ganglion cells-rods and cones-bipolar cells
E)bipolar cells-ganglion cells-rods and cones

Question 46

What condition is caused by uneven curvatures in the lens?

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

Question 47

In the visual pathway,

A)fibers from the medial side of a retina pass to the opposite side of the brain
B)fibers from the lateral side of a retina pass to the opposite side of the brain
C)fibers from the medial side of the retina pass to the same side of the brain
D)both a and b are true
E)both b and c are true

Question 48

An optic track carries information from

A)the lateral half of one retina and the medial half of the other retina
B)the lateral halves of both retinas
C)the medial halves of both retinas
D)an entire retina of one eye
E)half of the retina of one eye and the entire retina of the other eye

Question 49

Identify the structure required for hearing:

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

Question 50

Color vision

A)is perceived in the optic chiasma but is interpreted in the primary visual cortex
B)depends on various ratios of stimulation of the three cone types 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 51

Vitamin A deficiency causes

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

Question 52

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 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

Incoming visual information is relayed to the appropriate cortical tissue by

A)the ganglion cells
B)the lateral geniculate nuclei
C)thalamus
D)both a and b
E)both b and c

Question 55

Rods

A)are more sensitive to light than cones
B)have low acuity compared to cones
C)provide vision in shades of gray
D)exhibit all of the above
E)exhibit only characteristics a and c

Question 56

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 57

Emmetropia 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)excessive refractive power in the lens system of the eye
E)none of the above

Question 58

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 neurotransmitter release from the synaptic terminal
D)Decrease in cyclic GMP in the outer segment
E)Closure of Ca₂₊ channels in the synaptic terminal

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 the above.

Question 60

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)only b and c occur

Question 61

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 62

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 63

In which structure do sound waves first pass?

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

Question 64

Actual conversion of sound vibrations to nerve impulses occurs in the

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

Question 65

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)is characterized by all of the above

Question 66

The hair cells for hearing are located in the

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

Question 67

The oval window

A)attaches to the malleus
B)transfers the sound wave from the vestibule to the cochlea
C)is reflexively loosened in response to loud sounds to diminish transmission of these sounds to the inner ear
D)attaches to the stapes and relieves pressure inside the scala media
E)is not characterized by any of the above

Question 68

Deflection of the basilar membrane

A)activates receptors of the scala tympani
B)occurs in response to fluid movements in the utricle
C)results from vibrations in the round window
D)results from vibrations in perilymph around the scala media
E)causes otoliths to move back and forth

Question 69

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)is not characterized by any of the above

Question 70

The ossicular system of the ear

A)keeps 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 71

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

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

Question 72

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 73

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

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

Question 74

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
D)both a and c
E)none of the above

Question 75

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 76

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 the above

Question 77

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 78

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 the above occur

Question 79

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)are characterized by a and c
E)are characterized by b and c

Question 80

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