Sensation and Perception Questions - p. 3
61. Which area of the primary somatosensory cortex receives the most direct sensory input from the thalamus?
- A. area 1
- B. area 2
- C. area 3
- D. area 4
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Correct answer: C
The primary somatosensory cortex is typically divided into 3 areas: area 3 (which is often subdivided into area 3a and 3b), 1, and 2. Area 3 receives the majority of somatosensory input directly from the thalamus, and the initial processing of information occurs here.
62. Which nucleus of the thalamus serves as the primary relay for auditory information?
- A. lateral geniculate nucleus
- B. pulvinar nucleus
- C. medial geniculate nucleus
- D. ventral posterolateral nucleus
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Correct answer: C
The medial geniculate nucleus of the thalamus is the primary relay for auditory information, transmitting signals from the inferior colliculus to the auditory cortex in the temporal lobe.
63. What lobe of the brain is the primary auditory cortex found in?
- A. frontal
- B. parietal
- C. occipital
- D. temporal
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Correct answer: D
The primary auditory cortex is located in the temporal lobe of the brain, near the lateral (Sylvian) fissure. This region receives auditory information and is essential for processing basic features of sound such as pitch, loudness, and timing.
64. The majority of fibers in the optic tract project to the:
- A. superior colliculus
- B. lateral geniculate nucleus
- C. primary visual cortex
- D. medial geniculate nucleus
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Correct answer: B
Most axons in the optic tract terminate in the lateral geniculate nucleus (LGN) of the thalamus. The LGN serves as the primary relay center for visual information, sending projections via the optic radiations to the primary visual cortex in the occipital lobe.
65. The primary somatosensory cortex is located in which of the following regions?
- A. precentral gyrus
- B. postcentral gyrus
- C. superior temporal gyrus
- D. occipital lobe
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Correct answer: B
The primary somatosensory cortex lies in the postcentral gyrus, just posterior to the central sulcus.
66. True or false: The majority of people who experience an amputation also experience phantom limb sensations.
- A. True
- B. False
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Correct answer: A
Phantom limb is a condition in which someone who has lost a part of their body continues to experience phantom sensations coming from that body part. Phantom sensations are thought to be experienced by almost all amputees, and most suffer from some degree of phantom pain.
67. Which two cranial nerves are primarily responsible for carrying taste sensations from the tongue to the brain?
- A. glossopharyngeal (CN IX) & hypoglossal (CN XII)
- B. facial (CN VII) & glossopharyngeal (CN IX)
- C. Vagus (CN X) & hypoglossal (CN XII)
- D. Accessory (CN XI) & hypoglossal (CN XII)
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Correct answer: B
Taste information from the anterior two-thirds of the tongue is carried by the facial nerve (CN VII), while the glossopharyngeal nerve (CN IX) carries taste from the posterior one-third of the tongue.
68. Which cranial nerve is primarily responsible for carrying visual information from the retina to the rest of the brain?
- A. CN II - optic nerve
- B. CN III - oculomotor nerve
- C. CN IV - trochlear nerve
- D. CN VI - abducens nerve
Show Answer
Correct answer: A
The optic nerve is a sensory nerve responsible for transmitting information about vision to the brain.
69. A firecracker explodes in your hand, causing intense pain. Which ascending pathway carries this pain sensation to the brain?
- A. dorsal columns-medial lemniscus
- B. spinothalamic tract
- C. corticospinal tract
- D. spinocerebellar tract
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Correct answer: B
The spinothalamic tract is the primary pathway for carrying pain and temperature information from the body to the brain.
70. Which of the following structures is considered part of the olfactory cortex?
- A. dentate gyrus
- B. cingulate cortex
- C. insular cortex
- D. periamygdaloid cortex
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Correct answer: D
The olfactory cortex consists of a collection of cortical areas that receive information from the olfactory bulb, including the piriform cortex, an area of cortex surrounding the amygdala known as the periamygdaloid cortex, entorhinal cortex, and two regions known as the olfactory tubercle and anterior olfactory nucleus.
71. The cochlea contains three fluid-filled cavities. Which of the following correctly names these three cavities?
- A. scala vestibuli, scala media, and scala tympani
- B. scala vestibuli, vestibular duct, and tympanic duct
- C. scala vestibuli, scala cochlearis, and scala tympani
- D. scala media, vestibular canal, and tympanic canal
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Correct answer: A
The interior of the cochlea consists of three fluid-filled canals that run parallel to one another: the scala vestibuli, the scala media, and the scala tympani.
72. A person has damage to the left optic tract. Which visual deficit would you expect?
- A. blindness in the left eye
- B. blindness in the right eye
- C. loss of the left visual field in both eyes
- D. loss of the right visual field in both eyes
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Correct answer: D
After information from the two eyes reaches the optic chiasm, visual information is organized by visual field, not by eye. The left optic tract carries information from the right visual field of both eyes to the left side of the brain. So damage to the left optic tract would cause a loss of the right visual field in both eyes, also called a right homonymous hemianopia.
73. After entering the spinal cord, pain fibers often travel up or down one or more spinal segments before synapsing in the dorsal horn. These ascending and descending fibers travel in:
- A. Lissauer's tract
- B. fasciculus gracilis
- C. corticospinal tract
- D. Clarke's column
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Correct answer: A
The sensory neurons carrying pain signals enter the spinal cord through the dorsal root and branch off into ascending and descending collaterals that travel up or down the spinal cord for one or more segments in a collection of fibers known as Lissauer’s tract before synapsing in the dorsal horn, an area of gray matter in the spinal cord.
74. Which part of the retina contains no photoreceptors because it is the point at which ganglion cell axons leave the eye?
- A. fovea
- B. macula
- C. ora serrata
- D. optic disc
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Correct answer: D
Ganglion cells carry the visual signal out of the eye. They leave the eye in a large cluster at an area called the optic disc. The optic disc doesn't contain any photoreceptors, and so represents an area on the retina that can't process visual information, creating a natural blind spot.
75. The primary visual cortex is located around and within which sulcus of the occipital lobe?
- A. calcarine sulcus
- B. central sulcus
- C. parieto-occipital sulcus
- D. lateral sulcus
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Correct answer: A
The primary visual cortex, also known as V1, is a brain region that is critically important for the processing of visual information. It is found in the occipital lobe, surrounding and extending into a sulcus called the calcarine sulcus.
76. The first step in visual transduction occurs when which component of rhodopsin absorbs a photon of light?
- A. opsin
- B. retinal
- C. transducin
- D. phosphodiesterase
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Correct answer: B
Inside rod cells there is a light-sensitive pigment called rhodopsin, which consists of a protein called opsin and a light-absorbing molecule called retinal. When retinal absorbs a photon of light, it changes shape (from 11-cis-retinal to all-trans-retinal). This conformational change activates opsin, which then activates a G protein called transducin, initiating the process of visual transduction.
