Block 4 Worksheet Answers Flashcards
(209 cards)
1
Q
what receptor monitors limb position
A
golgi tendon organ
muscle spindle
proprioceptor
2
Q
what receptor monitors pain
A
free nerve ending
nociceptor
3
Q
what receptor is activated by muscle stretch
A
muscle spindle
4
Q
what receptor is a superficial vibration detector
A
meissner’s corpuscle
5
Q
what receptor is a deep pressure detector
A
ruffini ending
6
Q
what receptor monitors muscle tension
A
golgi tendon organ
7
Q
what receptor is a superficial pressure detector
A
merkel cell
8
Q
what receptor monitors muscle length
A
muscle spindle
9
Q
what receptor is a deep vibration detector
A
pacinian corpuscle
10
Q
what receptor monitors blood pressure, bladder volume, gut contraction
A
baroreceptor
11
Q
what pathway has information that crosses in the spinal cord
A
neospinothalamic
paleospinothalamic
12
Q
what pathway has information cross in the cerebellum
A
cuneospinocerebellar
dorsal spinocerebellar
13
Q
what pathway has information cross in the medulla
A
dorsal column
14
Q
what pathway has two tracts collectively referred to as anterolateral
A
neospinothalamic
paleospinothalamic
15
Q
what pathway conveys chronic low back pain
A
paleospinothalamic
16
Q
what pathway conveys unconscious proprioception
A
cuneospinocerebellar
dorsal spinocerebellar
17
Q
what pathway becomes activated if you stub your toe
A
neospinothalamic
18
Q
what pathway allows you to identify an object placed in your hand
A
dorsal column
19
Q
what pathway conveys acute/sharp pain info
A
neospinothalamic
20
Q
what pathway allows you to accurately catch a ball
A
cuneospinocerebellar
21
Q
what pathway conveys conscious somatosensation/proprioception
A
dorsal column
22
Q
what pathway activates when you have a stomach ache
A
paleospinothalamic
23
Q
what pathway allows you to accurately kick a ball
A
dorsal spinocerebellar
24
Q
what pathway primary afferent neuron does NOT synapse in the spinal cord
A
dorsal column
25
what pathway activates brainstem structures that provide descending pain modulation
paleospinothalamic
26
what term matches the pain description of: exaggerated painful response to a noxious stimulus
hyperalgesia
27
what term matches the pain description of: "normal pain"
nociciptive pain
28
what term matches the pain description of: neuropathic pain from an amputated limb
phanthom limb pain
29
what term matches the pain description of: pain that persists long after all tissue injury is healed
neuropathic pain
30
what term matches the pain description of: a painful response to a normally non-noxious stimulus
allodynia
31
what term matches the pain description of: mapping of visceral pain to a nearby somatic area
referred pain
32
Compare receptor potentials and action potentials
Receptor potential are graded and summed. In contrast, action potentials are all-or-none.
33
Compare somatosenstion and proprioception
Somatosensation involves cutaneous/skin receptors to detect fine touch, pressure, vibration, pain, and
temperature. Proprioception involves muscle, tendon, and joint receptors to detect muscle length, muscle tension and joint angle to determine where your body is in space.
34
Discuss why two tracts are required for proprioception
There are two types of proprioception - conscious and unconscious. Muscle spindles, Golgi tendon
organs and joint receptors are activated when the body moves. These receptors simultaneously activate two pathways - dorsal column-medial lemniscus and spinocerebellar. The dorsal column-medial lemniscus pathway does not synapse in the spinal cord, the first synapse is in the medulla in the gracile nucleus (leg information) or cuneate nucleus (arm information). The neurons in the nucleus cross, to become the medial lemniscus, to synapse in the contralateral thalamus, then the cortex; thus, detecting CONSCIOUS proprioception. The receptors for the spinocerebellar pathway synapse in the spinal cord and then send body position information to the ipsilateral cerebellum; thus, UNCONSCIOUS proprioception. The cerebellum then helps coordinate the movement and sends the information to the contralateral thalamus. At this point, the thalamus can compare the direct, unmodified info with the modified info from the cerebellum. The thalamus then sends the appropriate message to the cortex
35
Discuss why two spinothalamic tracts are required for pain
The body perceives two types of pain, sharp and dull. The sharp pain is acute and must be responded
to quickly. The neurons that convey sharp pain info synapse in the spinal cord, cross in the cord and goes directly to the thalamus, then cortex for fast perception. This pathway is referred to as neospinothalamic. Dull pain is chronic and there is descending systems in the brainstem and spinal cord that help modulate pain. The neurons that convey chronic pain info synapse in the spinal cord and cross in the cord like the sharp pain info, but as the axons ascend up to the thalamus, they send branches to two structures in the brainstem. One structure releases serotonin to decrease pain, another structure releases endogenous opiates. Together, this inhibits the ability of pain neurons to release substance P into the spinal cord and provides strong inhibition of pain. This pathway is referred to as paleospinothalamic.
36
An intensely painful stimulus is sensed differently than a mildly painful one due to
A. a greater frequency of action potential firing.
B. increased magnitude of action potential depolarization. C. a greater number of receptors activated.
D. all of the above
a greater frequency of action potential firing
37
Somatosensation, which is a combination of touch, pressure, stretch and vibration, primarily uses this type of receptor:
A. mechanoreceptors
B. nociceptors
C. proprioceptors D. thermoreceptors
mechanoreceptors
38
Which receptors adapt most quickly? A. nociceptors
B. pressure receptors C. proprioceptors
D. vibration receptors
vibration receptors
39
Spinocerebellar tracts
A. terminate in the spinal cord.
B. carry information about muscle or tendon stretch to the cerebellum. C. detect the conscious perception of touch.
D. are found in the dorsal columns of the spinal cord.
carry information about muscle or tendon stretch to the cerebellum.
40
This tract conveys information concerning extreme temperature and sharp pain: A. dorsal column-medial lemniscus
B. neospinothalamic
C. paleospinothalamic
D. spinocerebellar
neospinothalamic
41
what reflex is activated by a noxious stimulus
crossed extensor reflex
| withdraw reflex
42
what reflex is activated by muscle spindles
myotatic reflex
43
what reflex is activated by golgi tendon organs
inverse myotatic reflex
44
what reflex is a flexor reflex
crossed extensor reflex
| withdraw reflex
45
what reflex is a lengthening reflex
inverse myotatic reflex
46
what reflex is referred to as the patellar reflex
myotatic reflex
47
what reflex is a stretch reflex
myotatic reflex
48
is the corticobulbar tract part of the involuntary voluntary motor system
voluntary
49
is the anterior corticospinal tract part of the involuntary voluntary motor system
involuntary/postural
50
is the lateral corticospinal tract part of the involuntary voluntary motor system
voluntary
51
is the reticulospinal tract part of the involuntary voluntary motor system
involuntary/postural
52
is the rubrospinal tract part of the involuntary voluntary motor system
voluntary
53
is the tectospinal tract part of the involuntary voluntary motor system
involuntary/postural
54
is the vestibulospinal tract part of the involuntary voluntary motor system
involuntary/postural
55
what disorder is characterized by a shaky movement
tremor
56
what disorder is characterized by an increased resistance to passive extension
spasticity
57
what disorder is characterized by a result from damage to the basal ganglia
chorea, resting tremor
58
what disorder is characterized by increased reflexes due to reticulospinal tract damage
hyperreflexia
59
what disorder is characterized by a result from damage to lateral corticospinal tract
babinski sign
60
what disorder is characterized by a patient unable to maintain balance with eyes closed
romberg sign
61
what disorder is characterized by a jerky movement
chorea
62
what disorder is characterized by a result from cerebellar damage
ataxia, intention tremor
63
what disorder is characterized by clumsiness; shaky, unsteady movement
ataxia
64
what symptom would you have if you had dorsal root nerve damage
loss of sensory function only
65
what symptom would you have if you had lower motor neuron damage
loss of motor function only
66
what symptom would you have if you had spinal nerve damage
loss of sensory and motor function
67
what symptom would you have if you had upper motor neuron damage
hyperreflexia, spasticity
68
what symptom would you have if you had ventral root nerve damage
loss of motor function only
69
damage to the tract does not produce any clinical symptoms correlates to what structure
anterior corticospinal tract
corticobulbar tract
tectospinal tract
vestibulospinal tract
70
structure that regulates the starting and stopping of motor activities correlates to what structure
basal ganglia
71
damage to this tract causes a decerebrate posture correlates to what structure
rubrospinal tract
72
tract that innervates motor brainstem cranial nerve nuclei correlates to what structure
corticobulbar tract
73
located in cerebral cortex and brainstem, modulate alpha motor neurons correlates to what structure
upper motor neuron
74
tract that controls voluntary fine motor movements of distal muscles correlates to what structure
lateral corticospinal tract
75
damage to this tract causes a babinski sign correlates to what structure
lateral corticospinal tract
76
tract that primarily innervates arm flexors correlates to what structure
rubrospinal tract
77
damage to this tract produces a decorticate posture correlates to what structure
lateral corticospinal tract
78
tract that involves the superior colliculus correlates to what structure
tectospinal tract
79
damage to this structure results in intention tremor correlates to what structure
cerebellum
80
tract involved in the startle response correlates to what structure
tectospinal tract
81
tract that originates in the red nucleus correlates to what structure
rubrospinal tract
82
damage to this tract causes loss of RIFMs correlates to what structure
lateral corticospinal tract
83
tract activated by receptors in the inner ear correlates to what structure
vestibulospinal tract
84
tracts present in the cerebral peduncle correlates to what structure
anterior corticospinal tract
corticobulbar tract
lateral corticospinal tract
85
tract involved in maintaining balance correlates to what structure
vestibulospinal tract
86
tract that involves the inferior colliculus correlates to what structure
tectospinal tract
87
tracts present in the pyramids correlates to what structure
anterior corticospinal tract
| lateral corticospinal tract
88
structure that relates balance and refines the motor plan correlates to what structure
cerebellum
89
tract that primarily innervates neck and shoulder muscles correlates to what structure
tectospinal tract
90
located in brainstem and spinal cord, innervate skeletal muscles correlates to what structure
lower motor neuron
91
tracts that innervate motor neurons bilaterally correlates to what structure
anterior corticospinal tract
reticulospinal tract
tectospinal tract
vestibulospinal tract
92
damage to this structure results in resting tremor correlates to what structure
basal ganglia
93
damage t this tract produces hyperreflexia of deep tendon reflexes correlates to what structure
reticulospinal tract
94
tracts innervating postural muscles correlates to what structure
anterior corticospinal tract
reticulospinal tract
tectospinal tract
vestibulospinal tract
95
Compare the location and function of upper & lower motor neurons
Upper motor neurons are located in the cerebral cortex and brainstem. In the cortex, the neurons are the origin of the corticospinal tract to innervate the body and the corticobulbar tract to innervate the cranial nerve nuclei that have a motor function. Upper motor neurons don’t innervate muscle; rather, they control the lower motor neurons that innervate muscles. Damage to upper motor neurons in the corticospinal tract cause a loss of rapid independent finger movements (RIFMs), Babinski sign, and decorticate posture. Damage to the upper motor neurons of the rubrospinal tract causes a decerebrate posture. Damage to the upper motor neurons of the reticulospinal tract causes hyperreflexia and spasticity.
Lower motor neurons are located in the brainstem and spinal cord. These motor neurons DO innervate skeletal muscles. The lower motor neurons in the brainstem form the cranial nerves while the motor neurons in the spinal cord form spinal nerves. Damage to the lower motor neurons cause areflexia and muscle atrophy.
96
Compare the myotatic and inverse myotatic reflex
The myotatic and inverse myotatic reflexes are initiated by different receptors in response to
increased muscle length or tension. The myotatic reflex is activated by the muscle spindle receptor when it detects increased muscle length (e.g., hitting the patellar tendon lengthens the quadriceps muscles). To prevent the muscle from overstretching, the lower motor neuron activates the agonist muscle (the muscle that is being stretched) and an inhibitory neuron inhibits the antagonist muscle group (i.e., the hamstrings) to allow relaxation. The inverse myotatic reflex is activated by the Golgi tendon organ receptor when it detects increased muscle tension. To prevent muscle damage, the lower motor neuron activates the antagonist muscle group (e.g., if holding a weight, the triceps is activated to relieve tension in the biceps holding the weight) and an inhibitory neuron inhibits the agonist muscle group to relieve the tension.
97
Compare the function of the medial and lateral descending motor systems
There are two descending motor systems - medial and lateral. The medial system regulates
axial muscles to control posture. The medial motor system includes the anterior corticospinal tract (most postural control), tectospinal tract (startle reflex from the superior or inferior colliculus to CN XI lower motor neurons to innervate the trapezius and sternocleidomastoid muscles to turn the neck), vestibulospinal (activated by the fluid-filled vestibular apparatus in the inner ear to correct postural changes), and reticulospinal (inhibits extensor muscles). The lateral motor system includes the lateral corticospinal tract from the cortex to innervate lower motor neurons that innervate distal muscles for fine motor control and the rubrospinal tract from the red nucleus to the cervical enlargement to innervate lower motor neurons to forearm flexors.
98
The crossed-extensor reflex is important when:
a. someone taps on your patellar tendon.
b. you hold a barbell for too long.
c. you overextend your leg during the long jump.
d. you step barefoot on a sharp object.
you step barefoot on a sharp object.
99
pinocerebellar tracts
a. terminate in the spinal cord.
b. carry information about muscle or tendon stretch to the cerebellum.
c. give rise to conscious perception of touch and vibration.
d. are found in the dorsal columns of the spinal cord.
carry information about muscle or tendon stretch to the cerebellum
100
Which of the following statements is FALSE?
a. Damage to the primary motor cortex results in the loss of both voluntary muscle control and all reflexive contractions.
b. Damage to the premotor cortex results in loss of motor skills programmed in that area but movement is still possible.
c. Damage to the visual association area can result in the inability to interpret what is seen.
d. Damage to the primary auditory cortex results in the inability to interpret pitch, loudness, and location.
Damage to the primary motor cortex results in the loss of both voluntary muscle control and all reflexive contractions.
101
Which of the following tracts in involved in voluntary movement?
a. anterior corticospinal and rubrospinal
b. lateral corticospinal and corticobulbar
c. lateral corticospinal and tectospinal
d. reticulospinal and tectospinal
lateral corticospinal and corticobulbar
102
what visual structure is controlled by the sympathetic and parasympathetic nervous system
iris
103
what visual structure is the layer of the globe/eyeball that can develop skin cancer
choroid
104
what visual structure produces aqueous humor
ciliary body
105
what visual structure when damaged produces "tunnel vision"
optic chiasm
106
what visual structure produces tears
lacrimal glands
107
what visual structure is the most common organ transplant
cornea
108
what visual structure contains photoreceptors that detect black/white
rods
109
what visual structure contains axons of retinal ganglion cells that exit eye
optic nerve
110
what visual structure is fibrous tunic structure that gives eye its shape
sclera
111
what visual structure is the iris opening that allows light to enter the eye
pupil
112
what visual structure is a vascular layer of retina
choroid
113
what visual structure is a membrane that covers inner surface of eyelid
conjunctiva
114
what visual structure is a layer of eye that contains photoreceptors
retina
115
what visual structure is avascular fibrous tunic layer
cornea or sclera
116
what visual structure is "blind spot", part of retina lacking photoreceptors
optic disc
117
what visual structure is the external eye structure that protects the cornea
eyelashes
118
what visual structure are contact lens placed on
cornea
119
what visual structure is CSF-like liquid that provides nutrients to cornea
aqueous humor
120
what visual structure is the white of the eye
sclera
121
what visual structure are the photoreceptors that detect color
cone
122
what visual structure is the colored part of the eye
iris
123
what visual structure controls tension on lens
ciliary body
124
what visual structure when damage results in blindness to the eye
optic nerve
125
what visual structure provides most focusing power of the eye
cornea
126
what visual structure is the retinal area with most cone photoreceptors
macula/fovea
127
what visual structure is part of visual pathway for tracking of objects
superior colliculus
128
what visual structure is gelatinous material that helps maintain eye shape
vitreous humor
129
what disorder is described by accumulation of aqueous humor
glaucoma
130
what disorder is described by misalignment of the eyes
strabismus
131
what disorder is described by disorder when lens becomes cloudy
cataract
132
what disorder is described by far-sighted
hyperopia
133
what disorder is described by harmless breakdown product of the virtuous humor
floater
134
what disorder is described by misshaped cornea
astigmatism
135
what disorder is described by poor vision due to vitamin A deficiency
night-blindness
136
what disorder is described by double vision
diplopia
137
what disorder is described by near-sighted
myopia
138
what disorder is described by #1 cause of blindness
cataract
139
what disorder is described by #2 cause of blindness
glaucoma
140
what disorder is described by "pink eye"
conjunctivitis
141
what disorder is described by normal vision
emmetropia
142
what disorder is described by genetic defect in opsin protein
color blindness
143
what disorder is described by a warning sign of renal detachment
flasher
144
Why is color blindness more common in men than women?
Color blindness is caused by genetic alterations to the opsin photopigment protein. Photopigments (i.e., rod rhodopsin and cone iodopsin) have two parts - retinal (a vitamin A derivative) and opsin (a protein). Proteins are encoded by genes and the genes for the green and red opsin proteins are located on the X sex chromosome. If a man inherits an altered opsin gene from their mother (and the Y chromosome from their father) they will have colorblindness. However, if a woman inherits an altered X chromosome from their mother or father, they have a 50% chance of inheriting a normal X chromosome from their father and will be a “carrier”, but not be colorblind.
145
This visual disorder is caused by blockade of aqueous humor absorption, resulting in increased
intraocular pressure and compression of the retina and optic nerve: A. cataracts
B. glaucoma
C. presbyopia
D. strabismus
glaucoma
146
Activation of the sympathetic nervous system results in:
A. pupil constriction and increased far vision.
B. pupil constriction and increased near vision.
C. pupil dilation and increased far vision.
D. pupil dilation and increased near vision.
pupil dilation and increased far vision
147
```
What causes color blindness?
A. loss of rods within the retina
B. not enough vitamin A in the diet
C. altered green or red cones in the fovea
D. loss of central vision
```
altered green or red cones in the fovea
148
The elasticity of the lens decreases with age. This leads to:
A. clouding of the lens known as a cataract.
B. difficulty focusing on near objects known as presbyopia.
C. difficulty focusing on near objects known as myopia.
D. poor visual acuity (i.e., fuzzy vision) known as astigmatism
difficulty focusing on near objects known as presbyopia.
149
```
This visual structure controls the amount of light that strikes the retina:
A. ciliary body
B. cornea
C. iris
D. pupil
```
iris
150
is the auricle/pinna part of the inner, middle, or outer ear
outer
151
is the auditory ossicles part of the inner, middle, or outer ear
middle
152
is the cochlea part of the inner, middle, or outer ear
inner
153
is the eustachian tube part of the inner, middle, or outer ear
middle
154
is the malleus part of the inner, middle, or outer ear
middle
155
is the stapedius part of the inner, middle, or outer ear
middle
156
is the semicircular canals part of the inner, middle, or outer ear
inner
157
is the incus part of the inner, middle, or outer ear
middle
158
is the organ of corti part of the inner, middle, or outer ear
inner
159
is the tympanic membrane part of the inner, middle, or outer ear
outer
160
is the stapes part of the inner, middle, or outer ear
middle
161
is the tensor tympani part of the inner, middle, or outer ear
middle
162
is the vestibule (utricle/saccule) part of the inner, middle, or outer ear
inner
163
is the tympanic cavity part of the inner, middle, or outer ear
middle
164
what auditory structure is the muscle that reduces movement of the stapes at the oval window
stapedius
165
what auditory structure is the "anvil"
incus
166
what auditory structure is the structure that contains auditory receptors
organ of corti
167
what auditory structure is the inner ear structure for equilibrium and linear movement
vestibule
168
what auditory structure is the "eardrum"
tympanic membrane
169
what auditory structure is the middle ear bond attached to hammer and stirrup
incus
170
what auditory structure is the muscle that stiffen tympanic membrane
tensor tympani
171
what auditory structure is the canal that collects sound
external auditory canal
172
what auditory structure is the auditory ossicles
incus
malleus
stapes
173
what auditory structure is the "hammer"
malleus
174
what auditory structure is the middle ear bone attached to the oval window
stapes
175
what auditory structure is the inner ear structure ("snail") that contains auditory receptors
cochlea
176
what auditory structure is the inner ear structure that detects angular movement/rotation
semicircular canals
177
what auditory structure is the membrane that forms the "roof" over the organ of corti
tectorial membrane
178
what auditory structure is the canal that equalizes pressure in the middle ear
eustachian tube
179
what auditory structure is the "stirrup"
stapes
180
what auditory structure is the middle ear bone attached to tympanic membrane
malleus
181
what auditory structure is the muscles that protect ear from prolonged loud sounds
stapedius, tensor tympani
182
what auditory structure is the ear lobe
auricle/pinna
183
what auditory structure is the auditory receptors
hair cells
184
what auditory structure is the organ of court rests on this membrane
basilar membrane
185
what auditory structure is the cochlear membrane that sound vibration "exit"
round window
186
what auditory structure is the membrane attached to stirrup, transfers sound vibrations from middle ear to inner ear
oval window
187
Describe the function of the outer, middle, and inner ear and two structures in each that are
responsible for that function.
The outer ear is responsible for sound collection. The auricle/pinna/ear lobe collects the
sound and directs it down the external auditory canal.
The middle ear is responsible for converting weak air vibrations into stronger vibrations of liquid in the cochlea = sound amplification. The auditory ossicles ("ear bones"), including the malleus/hammer, incus/anvil, and stapes/stirrup, are responsible for converting the sound vibrations at the large tympanic membrane/ear drum to the smaller oval window of the cochlea. The two smallest muscles in the body, tensor tympani and stapedius, stiffen during prolonged loud noises to attenuate/dampen sounds to protect the delicate hair cells/auditory receptors in the cochlea.
The inner ear is responsible for sound detection and balance. The cochlea contains the organ of Corti that contains the auditory receptors for sound detection and the vestibular apparatus for balance/equilibrium
188
Compare the contribution of the semicircular canals and vestibule to balance.
Two structures are needed for balance and equilibrium. The vestibular apparatus
includes the semicircular canals for dynamic equilibrium and the vestibule for static equilibrium. The semicircular canals are a set of three fluid-filled tubes arranged in the X-, Y-, and Z- planes. Thus, the can detect spinning or angular movement in these planes. In contrast, the vestibule has two fluid-filled sacs that detect linear movements: the utricle detects horizontal movement & the saccule detects vertical movement.
189
what is described by a taste sensation to detect amino acids (meats, cheeses)
umami
190
what is described by sense that generates new neurons throughout life
olfaction
191
what is described by primary olfactory cortex is located in this lobe
frontal lobe
192
what is described by taste sensation to deter an energy source
sweet
193
what is described by receptor used for gustation
taste bud
194
what is described by primary gustatory cortex is located in this lobe
frontal lobe
195
what is described by taste sensation to detect potential poison
bitter
196
what is described by sense that is lost early in parkinson's disease
olfaction
197
what is described by taste sensation to detect sodium for physiological processes
salty
198
what is described by sense that synapses directly in the cortex
olfaction
199
what is described by taste sensation to elect potentially toxic acid
sour
200
what is described by olfactory epithelium cells that produce mucus
bowman's gland
201
what is described by sense that uses special epithelial cells, not neurons, as a receptor
gustation
202
name three cranial nerves that detect taste
CN VII, IX, X = facial, glossopharyngeal, vagus
203
Describe the three olfactory pathways and their function
1) contralateral olfactory bulb for smell localization
2) thalamus for smell perception/identification
3) directly to the limbic cortex in the temporal lobe for the emotional component of smell
204
Taste is 80% smell. The relationship between smell and taste is due to the fact that both
sensations use:
A. baroreceptors.
B. chemoreceptors. C. mechanoreceptors. D. proprioceptors.
chemoreceptors
205
The sensation of loudness of a sound is detected by
A. greater movement of the basilar membrane and hair cells.
B. vibration along a longer length of the basilar membrane, stimulating a greater number of hair cells.
C. faster vibration of the basilar membrane resulting in a higher frequency of hair cell movement.
D. vibration of the basilar membrane only at the base of the cochlea.
greater movement of the basilar membrane and hair cells.
206
Which of the following is NOT part of the external ear? A. Eustachian tube
B. externalacousticmeatus
C. pinna
D. tympanic membrane
Eustachian tube
207
Dynamic and static equilibrium both use: A. baroreceptors.
B. chemoreceptors.
C. mechanoreceptors.
D. proprioceptors.
mechanoreceptors.
208
Olfaction and gustation are similar in that both
A. are stimulated by substances in liquid form.
B. use neurons that are constantly generated throughout life.
C. synapse directly in the cortex without a thalamic relay.
D. are perceived in the parietal lobe.
are stimulated by substances in liquid form.
209
Monosodium glutamate is a food additive to enhance flavor due to activation of this taste sensation:
A. bitter B. salty C. sour
D. umami
umami
