Chapter 14

Watch this video (http://openstaxcollege.org/// DanielleReed) to learn about Dr. Danielle Reed of the Monell Chemical Senses Center in Philadelphia, PA, who became interested in science at an early age because of her sensory experiences. She recognized that her sense of taste was unique compared with other people she knew. Now, she studies the genetic differences between people and their sensitivities to taste stimuli. In the video, there is a brief image of a person sticking out their tongue, which has been covered with a colored dye. This is how Dr. Reed is able to visualize and count papillae on the surface of the tongue. People fall into two large groups known as "tasters" and "non-tasters" on the basis of the density of papillae on their tongue, which also indicates the number of taste buds. Non-tasters can taste food, but they are not as sensitive to certain tastes, such as bitterness. Dr. Reed discovered that she is a non-taster, which explains why she perceived bitterness differently than other people she knew. Are you very sensitive to tastes? Can you see any similarities among the members of your family?

The inability to recognize people by their faces is a troublesome problem. It can be caused by trauma, or it may be inborn. Watch this video (http://openstaxcollege.org/ l/faces) to learn more about a person who lost the ability to recognize faces as the result of an injury. She cannot recognize the faces of close family members or herself. What other information can a person suffering from prosopagnosia use to figure out whom they are seeing?

What type of receptor cell is responsible for transducing pain stimuli? a. mechanoreceptor b. nociceptor c. osmoreceptor d. photoreceptor

Which of these cranial nerves is part of the gustatory system? a. olfactory b. trochlear c. trigeminal d. facial

Which submodality of taste is sensitive to the \(\mathrm{pH}\) of saliva? a. umami b. sour C. bitter d. sweet

Axons from which neuron in the retina make up the optic nerve? a. amacrine cells b. photoreceptors c. bipolar cells d. retinal ganglion cells

What type of receptor cell is involved in the sensations of sound and balance? a. photoreceptor b. chemoreceptor c. mechanoreceptor d. nociceptor

Which of these sensory modalities does not pass through the ventral posterior thalamus? a. gustatory b. proprioception c. audition d. nociception

Which nucleus in the medulla is connected to the inferior colliculus? a. solitary nucleus b. vestibular nucleus c. chief sensory nucleus d. cochlear nucleus

Visual stimuli in the upper-left visual field will be processed in what region of the primary visual cortex? a. inferior right b. inferior left C. superior right d. superior left

Which location on the body has the largest region of somatosensory cortex representing it, according to the sensory homunculus? a. lips b. thigh C. elbow d. neck

Which of the following is a direct target of the vestibular ganglion? a. superior colliculus b. cerebellum c. thalamus d. optic chiasm

Which region of the frontal lobe is responsible for initiating movement by directly connecting to cranial and spinal motor neurons? a. prefrontal cortex b. supplemental motor area C. premotor cortex d. primary motor cortex

Which extrapyramidal tract incorporates equilibrium sensations with motor commands to aid in posture and movement? a. tectospinal tract b. vestibulospinal tract c. reticulospinal tract d. corticospinal tract

Which region of gray matter in the spinal cord contains motor neurons that innervate skeletal muscles? a. ventral horn b. dorsal horn c. lateral horn d. lateral column

What type of reflex can protect the foot when a painful stimulus is sensed? a. stretch reflex b. gag reflex c. withdrawal reflex d. corneal reflex

What is the name for the topographical representation of the sensory input to the somatosensory cortex? a. homunculus b. homo sapiens c. postcentral gyrus d. primary cortex

The sweetener known as stevia can replace glucose in food. What does the molecular similarity of stevia to glucose mean for the gustatory sense?

Why does the blind spot from the optic disc in either eye not result in a blind spot in the visual field?

Following a motorcycle accident, the victim loses the ability to move the right leg but has normal control over the left one, suggesting a hemisection somewhere in the thoracic region of the spinal cord. What sensory deficits would be expected in terms of touch versus pain? Explain your answer.

A pituitary tumor can cause perceptual losses in the lateral visual field. The pituitary gland is located directly inferior to the hypothalamus. Why would this happen?

The prefrontal lobotomy is a drastic- and largely outof-practice-procedure used to disconnect that portion of the cerebral cortex from the rest of the frontal lobe and the diencephalon as a psychiatric therapy. Why would this have been thought necessary for someone with a potentially uncontrollable behavior?

If a reflex is a limited circuit within the somatic system, why do physical and neurological exams include them to test the health of an individual?