Phys Test (Multiple Choice + T/F, Cha 10)

___ 38. During the processing and identification of odors such as that of a flower, neuron impulses passing through the spherically shaped glomeruli of the olfactory bulb are dulled by the phenomenon known as lateral inhibition. ___ 39. When odorant molecules bind to its specific olfactory receptor proteins embedded in the dendritic cilia of the bipolar sensory neurons, G-protein subunits are released that lead to the synthesis of cyclic AMP, the influx of Na+ and Ca2+ ions, local graded depolarization and firing of action potentials. ___ 40. Despite the recent discovery of a large family of genes (thousands in number) that code for about 300 olfactory receptor proteins, the fact that humans can distinguish up to 10,000 different odors continues to be unexplained. ___ 41. Sensory neurons in the olfactory bulb project action potentials from odorant molecules to the olfactory cortex in the medial temporal lobes and to the associated hippocampus and amygdaloid nuclei, thereby associating smells with emotion and memory.

False (sharpened, not dulled) True True True

___ 54. The utricle is most sensitive to vertical acceleration, while the saccule is most sensitive to horizontal acceleration. ___ 55. The portion of the vestibular apparatus featuring an ampulla, crista ampullaris, and cupula, is known as the saccule. ___ 56. When a gymnast performs forward somersaults, the hair cells located in the anterior semicircular canal of the vestibular apparatus are stimulated, whereas when doing cartwheels, those cells of the posterior semicircular canals are stimulated. ___ 57. Vestibular nystagmus refers to involuntary oscillations of the eyes, which may occur after a spinning person is stopped abruptly, and is also a symptom of Meniere's disease. ___ 58. The duct of Hensen is a tiny hole that permits the continuous flow of endolymph from the vestibular apparatus to the cochlea, thereby linking symptoms of vertigo to those of hearing deficits, such as in Meniere's disease.

False (utricle is horizontal, saccule is vertical) False (semicircular canals, not saccule) True True True

___ 111. The three types of cones responsible for human color vision contain retinene, as in rhodopsin; unlike rods, the retinene in the cones is associated with unique proteins called photopsins. ___ 112. Since the red (L) or green (M) types of cones are coded for by the Y chromosome in males, lack of such cones causes the more common red-green color blindness to occur in males rather than in females. ___ 113. The convergence of photoreceptors onto ganglion cells in the fovea centralis region of the retina is lower for the cones (1:1) than for the rods. ___ 114. The axons from the retina that pass through the superior colliculus of the midbrain (optic tectum) is needed to activate motor pathways and answer the visual question "What is it?". ___ 115. Smooth pursuit movements, saccadic eye movements, and vergence movements are three types of eye movements coordinated by the activity of neurons located in the midbrain, pons, and medulla oblongata regions of the brain.

True False (L & M are coded by male X-chromosome) True False (it answers 'Where') True

True or False/Edit ___ 82. Light of longer wavelengths (infrared) or shorter wavelengths (ultraviolet) than the visible light spectrum cannot be seen by the human eye. ___ 83. The anterior and posterior chambers are filled with a fluid called the vitreous body. ___ 84. The optic disc region (blind spot) of the eyeball contains neurons of the retina that exit only, whereas blood vessels are also present that both enter and exit from the optic disc. ___ 85. Both the visual field and the retina of each eye are divided into halves because light entering the eye is bent (refracted). ___ 86. The normal lens is composed of about a thousand layers of cells that are completely clear since they have no organelles, are not associated with blood vessels and their cytoplasm is filled with a protein called crystalline.

True False (aqueous humor, not vitreous body) True True True

___ 106. The visual cycle of retinal describes the interaction that occurs between the the photoreceptors that produce the all-trans form of retinal in response to light exposure and the nearby pigment epithelium cells that have the enzyme cis-trans isomerase, which is needed to re-convert the all-trans form back into the 11-cis form of retinal. ___ 107. During the bleaching reaction, there is a gradual increase in photoreceptor sensitivity, which reaches a maximum at about twenty minutes. ___ 108. The dark current describes the continuous leakage of Na+ through special Na+ channels as these ions diffuse into the photoreceptor cells. ___ 109. Light appears to hyperpolarize (inhibit) the rod and cone photoreceptors, causing the release of lower amounts of inhibitory neurotransmitter chemicals, and ultimately resulting in stimulation of the bipolar cells. ___ 110. The outer segment membranes of rods or cones have hundreds of regulatory G-proteins known as transducins that are activated by light, leading to the closure of Na+ channels, hyperpolarization of that rod or cone, release of less inhibitory neurotransmitter, and the eventual firing of action potentials to the brain.

True False (dark adaptation, not bleaching adaptation) True True True

True or False/Edit ___ 49. The sense of equilibrium can be described as the orientation of the body with respect to the pull of gravity. ___ 50. The sensory receptors of the vestibular apparatus and cochlea are located within a tubular "membranous labyrinth" filled with fluid, called perilymph. ___ 51. Perilymph is similar in ionic composition to cerebrospinal fluid (CSF). ___ 52. Rotational or angular acceleration is sensed by the semicircular canals. ___ 53. Hyperpolarization of hair cell membranes reduces the quantity of synaptic transmitter released that, in turn, reduces the frequency (impulses per minute) of action potentials.

True False (endolymph, not perilymph) True True True

True or False/Edit ___ 65. The intensity or loudness of a sound is directly related to the amplitude of the sound waves, and it is measured in units known as decibels. ___ 66. The auditory (eustachian) tube is a normally collapsed passageway leading from the inner ear to the nasopharynx. ___ 67. Damage to the tympanic membrane or middle ear ossicles, such as that caused by otitis media or otosclerosis, results in conduction deafness. ___ 68. The cochlear duct conducts pressure waves created by sound, and contains endolymph that bathes the sensory hair cells of the organ of Corti. ___ 69. The greater the displacement of the basilar mebrane and the bending of the stereocilia, the greater the frequency of action potentials produced which will be perceived as a louder sound.

True False (middle, not inner) True True True

True or False/Edit ___ 33. Chemoreceptors can be characterized as interoceptors or exteroceptors based on the source of the chemical stimuli. ___ 34. Both salt and sour tastes are mediated by membrane receptors that are coupled to G-proteins that, in turn, activate second-messenger systems within the cytoplasm of the taste receptor cell. ___ 35. The particular type of G-protein receptor found in the membranes of taste buds involved in the sensation of sweet, bitter, and umami has been identified and given the name transducin. ___ 36. Although all sweet taste receptors act via G-proteins that, in turn, activate second messenger systems, the sweet taste of sugar molecules may trigger a different second messenger system than does the sweet taste of artificial sweeteners (such as saccharin and cyclamate). ___ 37. Smell is the only sensation which does not generate action potentials that relay (synapse) in the thalamus region of the brain; instead, impulses generated by odorant molecules are transmitted directly to the cerebral cortex for processing.

True False (salt = Na+ ion, sour = H+ ion) False (gustducin, not transducin) True True

True or False/Edit ___ 121. Ganglion cells with on-center receptive fields are stimulated by light at the center of their visual fields, whereas those inhibited by light at the center and stimulated by light in the surround have off-center fields. ___ 122. Lateral geniculate neuron receptive fields of the thalamus, like ganglion cell receptive fields of the retina, are circular with an antagonistic center and surround areas.

True True

___ 24. Referred pain, such as that of angina pectoris, is believed to occur because seldom-used incoming neurons from the viscera can intersect with often-used somatic sensory neurons, resulting in pain from an internal organ being "felt" as coming from some remote somatic region, such as the left arm. ___ 25. Current theories regarding the phenomenon of the phantom limb propose that such sensations perceived may be produced by brain reorganization after the limb has been amputated and normal sensations are no longer present. ___ 26. In the fingertips, where a small area of skin is served by a large number of cutaneous receptors, the receptive field of each sensory neuron is correspondingly large. ___ 27. The two-point threshold test is used to measure the minimum distance on the skin between neighboring receptive fields for touch. ___ 28. Helping the brain distinguish borders of visual light and dark more sharply, or distinguish sounds of different pitch, or distinguish closely related odors, are all phenomena made possible by lateral inhibition.

True True False True True

___ 70. High pitched sounds produce peak displacement closer to the base of the basilar membrane, while lower pitched sounds cause peak displacement further toward the apex. ___ 71. As was true of the phantom limb syndrome, the brain shows a plasticity or an ability to reorganize the auditory cortex following trauma or deficit, such as in those with sensorineural deafness requiring implants. ___ 72. Nerve or sensory deafness can be caused by otitis media.

True True False (causes conduction deafness, not sensory deafness)

___ 88. An image will be seen in perfect focus only when the light waves from an object are bent (refracted) to a point on the retina itself. ___ 89. As an object moves away from you, the ciliary muscle relaxes, placing tension on the zonular fibers that pull the lens flatter or less convex to keep the image in focus. ___ 90. Myopia is also known as farsightedness. ___ 91. Astigmatism can be an abnormal curvature of either the cornea or the lens or both.

True True False (myopia is shortsightedness) True

True or False/Edit ___ 9. The term "modality" refers to the quality of sensation, such as sound, light, pressure, and so on. ___ 10. Sensory receptors are actually specialized neurons or dendrites of such neurons that may be free or encapsulated within nonneural structures. ___ 11. Nociceptors provide us with a sense of body position. ___ 12. Receptors that produce a relatively constant rate of firing as long as the stimulus is maintained are known as phasic receptors. ___ 13. Receptor potentials are the same as generator potentials since they are formed in sensory nerve endings (receptors) and serve to generate action potentials. ___ 14. All generator potentials reach threshold and fire action potentials from the periphery toward the brain.

True True False (proprioreceptors, not nociceptors) False (tonic, not phasic) True False (generator potentials are graded, and thus may be subthreshold)

___ 116. The superior colliculus (tectal system) is involved in the parasympathetic stimulation and contraction of the ciliary muscles of the iris during both accommodation and the pupillary reflex. 127 ___ 117. Fixational movements are very tiny and imperceptible movements of the eye that constantly "refresh" the visual fields of the eyes and prevents sensory adaptation due to bleaching or photodissociation reaction that would cause vision to fade. ___ 118. The pupillary reflex appears to be initiated by light striking the ganglion cell layer of the retina resulting in the release of a photoreceptive pigment, melanopsin, that also plays a role in regulation of the body's circadian (daily) rhythms.

True True True

True or False/Edit ___ 19. The capsaicin receptor for pain is activated by intense heat, whereas other pain receptors (nociceptors) may be activated by ATP molecules released from damaged cells or by a local fall in pH during infection or inflammation. ___ 20. Similar to the way capsaicin evokes heat sensation, cold or menthol can activate a membrane ion channel (receptor) of certain sensory neurons producing depolarization and the formation of sensory action potentials. ___ 21. Somatesthetic sensors include sensations from cutaneous receptors and proprioceptors. ___ 22. Somatesthetic information is projected to the postcentral gyrus of the ipsilateral cerebral hemisphere for interpretation. ___ 23. The larger area of the cortex devoted to the interpretation of face and hand sensation is due to the higher density of sensory receptors in the face and hands.

True True True False (contralateral, not ipsilateral) True

True or False/Edit ___ 101. Light must pass through several neuron cell layers before striking the photoreceptors (rods and cones) located in the retina. ___ 102. Ganglion cells of the retina synapse with, and are interconnected laterally to, amacrine cells. ___ 103. Within the retina are the pigment epithelial cells that are required for normal visual functions because they remove the old tip regions from photoreceptors cells and because they contain melanin pigment to absorb light. ___ 104. Cones contain a purple pigment known as rhodopsin, which is partially derived from vitamin A obtained from food in the diet. ___ 105. Since rods degenerate before cones, people with macular degeneration of the eye lose their peripheral (rod) vision first, whereas people with retinitis pigmentosa lose their central (cone) vision first and therefore must try to see from the "corners fo their eyes."

True True True False (rods = rhodopsin) False (retinitis pigmentosa affects rods, macular degeneration affects cones)

Which of the following is not part of the functional unit of the cochlea known as the organ of Corti? a. Reissner's membrane b. basilar membrane c. tectorial membrane d. inner and outer hair cells with sensory fibers

a. Reissner's membrane

A cylindrical lens is prescribed to correct for a. astigmatism. b. myopia. c. hyperopia. d. presbyopia. e. Cylindrical lenses are not used for correction.

a. astigmatism.

Which of the following is not part of the vestibular apparatus? a. cochlea b. otolith organs c. utricle d. saccule e. semicircular canals

a. cochlea

The portion of the eye with the greatest refractive index (where light is refracted most) is the a. cornea. b. aqueous humor. c. lens. d. vitreous body. e. retina.

a. cornea.

The structures of the eye that transmit and refract light are the a. lens and cornea. b. lens and choroids. c. cornea and iris. d. cornea and choroids. e. lens and sclera.

a. lens and cornea.

The difference between a strong stimulus (for example, hot) and a weak stimulus (for example, warm) is that the strong stimulus a. produces a greater number of action potentials per unit of time (frequency). b. produces action potentials having greater strength (amplitude). c. routes action potentials to more sensitive brain areas. d. produces action potentials that last a longer period of time (duration).

a. produces a greater number of action potentials per unit of time (frequency).

The medial lemniscus is a sensory fiber tract of second-order neurons relaying cutaneous information to the a. thalamus. b. medulla oblongata. c. spinal cord. d. cerebral cortex. e. None of these regions receives information from the medial lemniscus.

a. thalamus.

The otolith membrane is an important part of the a. utricle and saccule. b. vestibular apparatus. c. semicircular canals. d. cochlea.

a. utricle and saccule.

Which of the following about myopia is false? a. It is also known as nearsightedness. b. It may result from an eyeball that is too short. c. It is corrected by glasses with concave lenses. d. The blurry image is focused in front of the retina.

b. It may result from an eyeball that is too short.

Which of the following is not characteristic of taste buds? a. They have long microvilli at their apical (top) opening to the surface. b. They are characterized as interoceptors. c. They respond to chemicals dissolved in saliva. d. Along the tongue, they are innervated by two different cranial nerves. e. Although taste bud cells are not neurons, they are able to depolarize and release chemical transmitters when stimulated.

b. They are characterized as interoceptors.

Accommodation, the ability of the eyes to keep the image focused on the retina as distance is changed, results from contraction of the a. circular muscles. b. ciliary muscles. c. radial muscles. d. pupil.

b. ciliary muscles.

Which of the following types of neurons is not a cortical neuron found in the striate cortex region of the occipital lobe (Brodmann's areas 17, 18, and 19)? a. simple b. circular c. complex d. hypercomplex e. rectangular

b. circular

Which of the following statements about the rod and cone photoreceptors is false? a. each consists of an inner and an outer segment b. each inner segment contains hundreds of flattened membranous sacs, or discs c. each outer segment contains photopigment molecules required for vision d. retinal pigment epithelial cells have important interactions with rods and cones during vision e. All of these statements about photoreceptors are true.

b. each inner segment contains hundreds of flattened membranous sacs, or discs

The pitch of a sound is directly related to the ______ of sound waves and is measured in units called ______. a. amplitude; hertz b. frequency; hertz c. amplitude; decibels d. frequency; decibels

b. frequency; hertz

The outer layer of neurons in the retina whose axons gather to form the optic nerve tract are called a. bipolar cells. b. ganglion cells. c. horizontal cells. d. amacrine cells. e. photoreceptor cells.

b. ganglion cells.

Which of the following is not a cutaneous receptor? a. touch receptor b. joint receptor c. pain receptor d. temperature receptor e. All of these are cutaneous receptors.

b. joint receptor

Most (70% to 80%) of the ganglion cell axons from the retina exit the eye as the optic nerve and pass immediately to the a. superior colliculus of the midbrain (optic tectum). b. lateral geniculate nucleus of the thalamus. c. striate cortex of the occipital lobe. d. Brodmann areas 17, 18, and 19 of the occipital lobe.

b. lateral geniculate nucleus of the thalamus.

A common visual impairment in older people whose vision loses clarity within the central fovea portion of the visual field, perhaps due to the loss of retinal pigment epithelium in this region, is a. retinitis pigmentosa. b. macular degeneration. c. cataracts. d. glaucoma. e. Meniere's disease.

b. macular degeneration.

Which is not one of the four basic taste modalities? a. bitter b. metallic c. salty d. sour e. sweet

b. metallic

Which of the following is not a mechanoreceptor? a. touch receptor b. pain receptor c. pressure receptor d. inner ear hair cell (for hearing) e. vestibular hair cell (for balance)

b. pain receptor

Arrange the following events in proper sequence. 1. Hair cell membrane is depressed; hair cells depolarize. 2. Stereocilia are bent in the direction of the kinocilium. 3. Newly generated action potentials race along the eighth cranial nerve. 4. The body (and head) move or accelerate linearly. 5. Hair cells release synaptic transmitter substances. a. 2, 5, 4, 1, 3 b. 4, 3, 2, 1, 5 c. 4, 2, 1, 5, 3 d. 2, 3, 1, 5, 4

c. 4, 2, 1, 5, 3

Which statement about lateral inhibition is false? a. It occurs via inhibitory interneurons in the central nervous system (CNS). b. Weaker, neighboring input is inhibited from reaching the brain. c. It is characteristic only of receptors in the skin (cutaneous). d. It results in a sharpening of sensation with perception that is more well-defined than the original stimulus that was applied.

c. It is characteristic only of receptors in the skin (cutaneous).

Glaucoma is best described as a condition in which the a. lens and cornea may become cloudy or translucent, making it difficult for light to be transmitted. b. retina may become detached, resulting in blindness. c. canal of Schlemm is blocked, causing the intraocular pressure to rise. d. normal pigments of the retina are not synthesized, so that light reflection interferes with vision.

c. canal of Schlemm is blocked, causing the intraocular pressure to rise.

The structure of the eye that is darkly pigmented to absorb light within the eyeball, and thereby prevent reflection, is the a. cornea. b. sclera. c. choroids. d. ciliary body. e. retina.

c. choroids.

The pitted portion of the retina upon which the image of the objects we look at falls, and which contains almost all cones for greatest visual acuity, is called the a. ganglion cell layer. b. optic disc. c. fovea centralis. d. pigmented epithelium. e. choroid layer.

c. fovea centralis.

As light enters the eye, the neurons of the retina directly responsible for generating the all-or-none action potentials that are conveyed out optic nerve are the a. photoreceptor cells only. b. bipolar cells and horizontal cells. c. ganglion cells and amacrine cells. d. horizontal cells only.

c. ganglion cells and amacrine cells.

Which of the following is not a chemoreceptor? a. taste bud b. olfactory epithelium c. hot and cold receptors d. aortic and carotid bodies e. All of these are chemoreceptors.

c. hot and cold receptors

Which of the following sensations does not adapt quickly, if at all, to constant stimuli? a. temperature b. touch c. pain d. odor e. All of these sensations adapt quickly.

c. pain

Hair cells, ampulla, and cupula are located in the a. utricle and saccule. b. vestibular apparatus. c. semicircular canals. d. cochlea.

c. semicircular canals.

Angular or rotational acceleration is sensed by a. the utricle only. b. the saccule only. c. the semicircular canals. d. both the utricle and saccule.

c. the semicircular canals.

Which of the following is not a proprioceptor? a. muscle spindle b. Golgi tendon organ c. touch and pressure receptors d. joint receptors

c. touch and pressure receptors

Which color (wavelength of light) is not designated as one of the three (trichromatic) types of cones? a. blue b. red c. yellow d. green

c. yellow

The tip of the index finger is very sensitive because a. the size of each receptive field is very small. b. the density of its touch receptors is very high. c. its representative area on the cortex is very large. d. All of these help explain this fingertip sensitivity.

d. All of these help explain this fingertip sensitivity.

Which of the following is not true of conduction deafness? a. It impairs hearing at all sound frequencies. b. It results when the transmission of sound waves from the air through the middle ear to the oval window is impaired. c. It may be caused by otitis media or otosclerosis. d. It is the cause of age-related hearing deficits known as presbycusis. e. All of these are true regarding conduction deafness.

d. It is the cause of age-related hearing deficits known as presbycusis.

Which of the following statements about the autonomic nerve control over smooth muscles of the pupil is true? a. Parasympathetic stimulation of circular muscles causes the iris to dilate. b. Parasympathetic stimulation of radial muscles causes the iris to constrict. c. Sympathetic stimulation of the radial muscles causes the iris to constrict. d. Sympathetic stimulation of the radial muscles causes the iris to dilate.

d. Sympathetic stimulation of the radial muscles causes the iris to dilate.

Information about linear acceleration is sensed by a. the utricle only. b. the saccule only. c. the semicircular canals. d. both the utricle and saccule.

d. both the utricle and saccule.

Somatesthetic action potentials are perceived by the a. thalamus. b. medulla oblongata. c. spinal cord. d. cerebral cortex (postcentral gyrus).

d. cerebral cortex (postcentral gyrus).

Neurons of the visual (occipital) cortex respond to all of the following forms of stimuli except a. slits or bars of light. b. straight lines with a specific orientation and direction. c. particular lengths, corners or edges. d. circles with on and off centers with surrounds.

d. circles with on and off centers with surrounds.

The receptors for the sense of equilibrium are modified epithelial cells called a. chemoreceptors. b. proprioceptors. c. stereocilia. d. hair cells. e. kinocilia.

d. hair cells.

The pacinian, or lamellated corpuscle, is a cutaneous receptor for perception of a. heat. b. cold. c. touch. d. pressure. e. pain.

d. pressure.

Which of the following taste modality evokes a pleasant, "meaty" sensation in response to specific amino acid molecules in food proteins? a. salty b. sour c. bitter d. umami e. sweet

d. umami

Which of the following does not apply to the law of specific nerve energies? a. Stimulation of a sensory nerve fiber produces only one sensation, such as touch, cold, pain, and so on. b. Each sensory neuron responds to its own normal, or adequate, stimulus with a characteristic sensation. c. Sensory neurons may respond to "injury currents" as readily as they do to "normal" stimuli. d. Paradoxical cold is an example of the law of specific nerve energies. e. All of these apply.

e. All of these apply.

Which is not a characteristic of olfactory sensation? a. Olfactory receptors can be classified as chemoreceptors and exteroceptors. b. Olfactory receptors are bipolar neurons that are unique, dividing by mitosis to replace themselves every month or two. c. Olfactory information (smell) is perceived in the limbic system region of the cerebral cortex. d. Smells can affect both memory and emotion. e. All of these are characteristic of olfactory sensation.

e. All of these are characteristic of olfactory sensation.

Which of the following is not considered an important function of the pigment epithelium of the retina? a. phagocytosis of the shed outer segments of the rods and cone photoreceptors b. produce melanin pigments to absorb light and improve vision in the retina c. help deliver nutrients (and molecules such as retinal) from the blood to the photoreceptors d. help suppress immune attacks against the retina e. All of these are functions of the pigmented epithelium.

e. All of these are functions of the pigmented epithelium.

Which of the following is not part of the neural pathway leading to the interpretation of sound by the brain? a. the sensory inner hair cells of the organ of Corti b. the inferior colliculus of the midbrain (corpora quadrigemina) c. the vestibulocochlear (eighth cranial) nerve d. the thalamus (medial geniculate) e. All of these are part of the neural pathway for sound.

e. All of these are part of the neural pathway for sound.

As opposed to rods, the cones a. are less sensitive in low light conditions. b. provide color vision. c. provide greater visual acuity (sharpness of detail). d. are more responsive in the daylight. e. All of these correctly describe cones.

e. All of these correctly describe cones.

Which of the following does not occur during pitch discrimination of sound performed by the spiral organ (Organ of Corti)? a. At low sound intensities outer hair cells seem to function as cochlear amplifiers by contracting or elongating in synchrony with the inner hair cells response to sound waves. b. Higher pitches of sounds produce peak displacement of the basilar membrane closer to the base of the spiral organ. c. The displacement of stereocilia by pressure (sound) waves in the endolymph depolarizes underlying inner hair cells that release a neurotransmitter such as glutamate that stimulates an associated sensory neuron. d. Neurons in the CNS may apply lateral inhibition to sharpen the discrimination of pitch. e. All of these occur during pitch discrimination of sound.

e. All of these occur during pitch discrimination of sound.

The louder the sound intensity entering the ear, the greater the a. amplitude of action potentials formed by sensory hair cells. b. frequency of action potentials formed by sensory hair cells. c. displacement of the basilar membrane. d. Both A and C are correct. e. Both B and C are correct.

e. Both B and C are correct.

Which statement about visual field halves and the retina halves is correct? a. The left visual field focuses on the left half-retina. b. The left visual field focuses on the right half-retina. c. The nasal half-retina of the right eye receives the same image as the temporal half-retina of the left eye. d. The nasal half-retina of the right eye receives the same image as the nasal half-retina of the left eye. e. Both B and C are correct.

e. Both B and C are correct.