1
Q
What does the hearing identification involve?
A
Identification of the sounds “what”
2
Q
What does the hearing localization involve?
A
Localization of the sounds “where”
3
Q
What are sound waves made of?
A
Sound waves are made when air molecules move back and forth (travelling vibrations of air)
4
Q
What is compression?
A
air molecules pushed close together (high pressure)
5
Q
What is rarefaction?
A
air molecules spread out (low pressure)
6
Q
What are the 3 parts of the ear?
A
External Ear
Middle Ear
Inner Ear
7
Q
What does the External Ear consist of?
A
pinna, external auditory meatus, tympanic membrane (eardrum)
8
Q
What does the Middle Ear consist of?
A
auditory ossicles (malleus, incus, stapes)
9
Q
What does the inner ear consist of?
A
Cochlea and Vestibular apparatus
10
Q
Where are the receptors for sound located?
A
In the fluid-filled inner ear
11
Q
What protects the ear canal?
A
The ear canal is lined with fine hairs and earwax glands (ceruminous glands)
12
Q
What does earwax (cerumen) do?
A
traps dust and particles
13
Q
How does hair protect the ear canal?
A
blocks large debris
14
Q
What does the Malleus (hammer) attach to?
A
Malleus attaches to eardrum
15
Q
What does the Incus (anvil) attach to?
A
Incus attaches to middle bone
16
Q
What does the Stapes (stirrup) attach to?
A
Stapes attaches to oval window of cochlea
17
Q
What do sensory systems does the Inner Ear hold?
A
Cochlea and Vestibular Apparatus
18
Q
What does the cochlea do?
A
contains receptors for conversation of sound waves into nerve impulses, which makes hearing possible
19
Q
What does the vestiubular apparatus do?
A
necessary for sense of equilibrium
20
Q
Where is the cochlea and what does it do?
A
Located in inner ear, hearing organ
21
Q
Which part of the ear is snail shaped and responsible for hearing?
A
Cochlea
22
Q
What 3 fluid-filled chambers make up the cochlea?
A
Scala Vestibuli (top)
Cochlear Duct / Scala media (middle)
Scala Tympani (bottom)
23
Q
Which is the top chamber of the cochlea?
A
Scala Vestibuli - filled with perilymph fluid
24
Q
Which is the middle chamber of the cochlea?
A
Cochlear Duct / Scala media - filled with endolymph fluid
25
What is the bottom chamber of the cochlea?
Scala tympani - filled with perilymph fluid
26
Which chamber of the cochlea is filled with endolymph fluid?
Cochlear duct / Scala media - middle layer
27
What is the Scala vestibular chamber filled with?
Top layer - filled with perilymph fluid
28
What is the Scala tympani chamber filled with?
Bottom layer - filled with perilymph fluid
29
Which structure is responsible for hearing?
a. Semicircular canals
b. Cochlea
c. Eustachian tube
d. Tympanic cavity
b. Cochlea
30
The cochlea is described as which type of structure?
a. Tube-shaped
b. Snail-shaped
c. Dome-shaped
d. Spiral-shaped only
b. Snail-shaped
31
Which chamber of the cochlea is filled with endolymph fluid?
a. Scala vestibuli
b. Scala tympani
c. Cochlear duct / Scala media
d. Oval window
c. Cochlear duct / Scala media
32
Which chambers are filled with perilymph fluid?
a. Only the cochlear duct
b. Scala vestibuli and scala tympani
c. Cochlear duct and scala tympani
d. Only scala tympani
b. Scala vestibuli and scala tympani
33
Sound vibrations enter the cochlea through which structure?
a. Round window
b. Basilar membrane
c. Cochlear duct
d. Oval window (via stapes)
d. Oval window (via stapes)
34
How do sound vibrations travel through the cochlea?
enter at the oval window (via stapes), travel through cochlear fluids, exit at round window
35
Sound vibrations exit the cochlea through which structure?
a. Round window
b. Basilar membrane
c. Cochlear duct
d. Oval window (via stapes)
a. Round Window
36
What supports the Organ of Corti?
a. Tectorial membrane
b. Basilar membrane
c. Tympanic membrane
d. Cochlear nerve
b. Basilar membrane
37
What happens to sound vibrations after entering the oval window?
a. They travel through cochlear fluids and exit at the round window
b. They are absorbed by the tympanic membrane
c. They stay in the scala tympani only
d. They bypass the cochlear fluids
a. They travel through cochlear fluids and exit at the round window
38
What does the Organ of Corti do?
a. Produces perilymph
b. Amplifies mechanical energy
c. Converts mechanical vibrations into nerve signals for hearing
d. Balances pressure between chambers
c. Converts mechanical vibrations into nerve signals for hearing
39
Which of the following correctly pairs a chamber with its fluid?
a. Scala vestibuli – endolymph
b. Scala tympani – endolymph
c. Cochlear duct – perilymph
d. Scala media – endolymph
d. Scala media - endolymph
40
Pressure waves move which structure?
a. Round window
b. Basilar membrane
c. Tympanic membrane
d. Stapes
b. Basilar membrane
41
Which fluid-filled chamber is located at the top of the cochlea?
A. Scala Vestibuli
B. Cochlear Duct / Scala Media
C. Scala Tympani
A. Scala Vestibuli
42
Which fluid-filled chamber is located at the middle of the cochlea?
A. Scala Vestibuli
B. Cochlear Duct / Scala Media
C. Scala Tympani
B. Cochlear Duct / Scala Media
43
Which fluid-filled chamber is located at the bottom of the cochlea?
A. Scala Vestibuli
B. Cochlear Duct / Scala Media
C. Scala Tympani
C. Scala Tympani
44
Which of the following lists the two types of hair cells?
a. Apical and basal
b. Type I and Type II only
c. Inner and outer
d. Primary and secondary
c. Inner and outer
45
What are the tiny hairs on each hair cell called?
a. Kinocilia
b. Axons
c. Stereocilia
d. Microvilli
c. Stereocilia
46
Stereocilia touch which structure?
a. Basilar membrane
b. Oval window
c. Scala vestibuli
d. Tectorial membrane
d. Tectorial membrane
47
What is a gel-like structure that sits above the hair cells in the organ of Corti?
a. Basilar membrane
b. Oval window
c. Scala vestibuli
d. Tectorial membrane
d. Tectorial membrane
48
What happens to stereocilia when sound vibrations move the membrane?
a. Hair cells are replaced
b. The stereocilia bend, starting the process of hearing
c. The oval window opens
d. The stapes detaches
b. The stereocilia bend, starting the process of hearing
49
Which event begins the process of hearing?
a. Eardrum vibration
b. Movement of the stapes
c. Bending of stereocilia
d. Opening of the Eustachian tube
c. Bending of stereocilia
50
Which of the following is NOT a major category of somatosensory receptor?
a. mechanoreceptors
b. thermoreceptors
c. chemoreceptors
d. steroid receptors
d. steroid receptors
51
Which of the following would NOT be sensed by a mechanoreceptor?
a. stretch
b. pressure
c. temperature
d. vibration
c. temperature
52
Which structure of the ear contains the auditory ossicles?
a. middle ear
b. vestibular apparatus
c. external ear
d. cochlea
a. middle ear
53
Which of the following is NOT one of the five established taste categories?
a. spicy
b. bitter
c. sour
d. sweet
a. spicy
54
Which of these statements refers to olfactory receptor cells? STUDY
a. They synapse on interneurons before entering the brain.
b. Each receptor cell responds to only one component of an odour.
c. They are efferent neurons.
d. They cannot be replaced if damaged.
b. Each receptor cell responds to only one component of an odour.
55
What property of an odorant is necessary for smell detection?
a. easily vaporized
b. detectable by one of the three receptor types
c. lipid soluble
d. sufficiently large
a. easily vaporized
56
Which of the following pairings of autonomic nervous system systems with effects on target organs is correct?
a. parasympathetic system — dilation of pupil
b. sympathetic system — reduce heart rate
c. parasympathetic system — constrict bronchioles
d. sympathetic system — contraction of bladder
c. parasympathetic system — constrict bronchioles
57
What do somatic motor neurons innervate?
a. cardiac muscle
b. skeletal muscle
c. salivary glands
d. endocrine glands
b. skeletal muscle
58
Where do sound waves enter?
a. Scala vestibuli
b. Auditory canal
c. Oval window
d. Cochlear duct
b. Auditory canal
59
What is the tympanic membrane?
eardrum
60
The tympanic membrane (eardrum) vibrates:
a. Randomly
b. Faster than sound waves
c. At the same frequency as the sound waves
d. Only during loud sounds
c. At the same frequency as the sound waves
61
Which order do vibrations pass through the ossicles?
a. Incus → Malleus → Stapes
b. Stapes → Malleus → Incus
c. Malleus → Incus → Stapes
d. Stapes → Incus → Malleus
c. Malleus → Incus → Stapes
62
What do the ossicles do during mechanical amplification?
a. Reduce sound pressure
b. Amplify sound pressure
c. Block loud frequencies
d. Create action potentials
b. Amplify sound pressure
63
What pushes on the oval window to set cochlear fluid into motion?
a. Incus
b. Malleus
c. Tympanic membrane
d. Stapes
d. Stapes
64
Fluid movement in the cochlea creates pressure waves that travel through:
a. Scala media only
b. Scala vestibuli and scala tympani
c. Cochlear duct only
d. Eustachian tube
b. Scala vestibuli and scala tympani
65
Which structure moves up and down with the fluid waves?
a. Tectorial membrane
b. Basilar membrane
c. Round window
d. Vestibular membrane
b. Basilar membrane
66
Movement of the basilar membrane causes what?
a. Bending of hair cell bodies
b. Bending of stereocilia on the hair cells of the Organ of Corti
c. Compression of ossicles
d. Opening of Eustachian tube
b. Bending of stereocilia on the hair cells of the Organ of Corti
67
During transduction, bending of stereocilia opens:
a. Sodium pumps
b. Ion channels
c. Vesicles
d. Receptors on fluid membranes
b. Ion channels
68
What do receptor potentials trigger?
a. Movement of endolymph
b. Tympanic reflex
c. Action potentials in the auditory nerve
d. Pressure waves in the scala media
c. Action potentials in the auditory nerve
69
Where does the signal travel after the auditory nerve?
a. Cochlear duct
b. Organ of Corti
c. Stapes
d. Brain
d. Brain
70
Which process converts mechanical energy → neural signal?
a. Amplification
b. Resonance
c. Transduction
d. Pressure wave conduction
c. Transduction
71
List the Sound Transduction Steps
slide 23**
1. Sound entry
2. Mechanical Amplification
3. Fluid Movement in the Cochlea
4. Basilar Membrane & Hair Cells
5. Transduction
72
What is the correct pathway of sound signals to the auditory cortex?
Hair cells → Auditory nerve → Brainstem → Thalamus (Medial Geniculate Nucleus) → Auditory cortex
73
What does the brainstem use sound input for?
Alertness & reflexes
74
What does the thalamus act as?
b. A sensory relay, directing signals (except smell) to the correct brain area
75
Each region of the basilar membrane connects to what?
a. The cochlear nerve only
b. A matching region of the primary auditory cortex
c. The semicircular canals
d. The brainstem nuclei
b. A matching region of the primary auditory cortex
76
Specific cortical neurons in the auditory cortex respond only to:
a. Smell
b. Loudness
c. Particular tones
d. Speech patterns
c. Particular tones
77
Which cortex perceives discrete sounds (tones)?
a. Primary cortex
b. Higher-order cortex
c. Reflex cortex
d. Prefrontal cortex
a. Primary cortex
78
Which cortex integrates sounds into meaningful patterns (e.g., speech, music)?
a. Primary cortex
b. Higher-order cortex
c. Sensory cortex
d. Reflex cortex
b. Higher-order cortex
79
Where do auditory signals from both ears project?
a. Left temporal lobe only
b. Right temporal lobe only
c. Both temporal lobes
d. Only to the brainstem
c. Both temporal lobes
80
Damage above the brainstem causes:
a. Total hearing loss
b. Partial, not total, hearing loss
c. No effect on hearing
d. Loss of smell
b. Partial, not total, hearing loss
81
Conductive deafness occurs when:
a. Sound waves reach the inner ear but aren’t converted into nerve impulses
b. Sound waves aren’t conducted properly through the outer or middle ear
c. Hair cells send too many action potentials
d. The auditory cortex is overstimulated
b. Sound waves aren’t conducted properly through the outer or middle ear
82
What causes Conductive deafness?
earwax blockage, eardrum rupture, middle-ear infection, stiff ossicles
83
Sensorineural deafness occurs when:
a. Sound waves reach the inner ear but aren’t converted into nerve impulses
b. Sound waves aren’t conducted properly through the outer or middle ear
c. Hair cells send too many action potentials
d. The auditory cortex is overstimulated
a. Sound waves reach the inner ear but aren’t converted into nerve impulses
84
Damage leading to sensorineural deafness may occur in:
a. The tympanic membrane or ossicles
b. The Organ of Corti, auditory nerve, or auditory cortex
c. The Eustachian tube
d. The round window
b. The Organ of Corti, auditory nerve, or auditory cortex
85
Hearing aids are helpful for:
a. Sensorineural deafness only
b. Conductive loss; amplify sound but require intact nerve pathways
c. Damaged basilar membrane
d. Damage in the auditory cortex
b. Conductive loss; amplify sound but require intact nerve pathways
86
Cochlear implants:
a. Only amplify sound
b. Require intact hair cells
c. Bypass damaged hair cells and directly stimulate the auditory nerve
d. Only help with balance, not hearing
c. Bypass damaged hair cells and directly stimulate the auditory nerve
87
Cochlear implants allow users to:
a. Hear only loud sounds
b. Recognize environmental sounds or hold phone conversations
c. Restore their hair cells
d. Restore full natural hearing
b. Recognize environmental sounds or hold phone conversations
88
Emerging research is exploring:
a. Earwax removal techniques
b. Stiffening of the ossicles
c. Hair-cell regeneration and neural growth factors to restore hearing
d. Preventing sound from reaching the cochlea
c. Hair-cell regeneration and neural growth factors to restore hearing
89
Where is the vestibular apparatus located?
a. Outer ear
b. Middle ear
c. Inner ear
d. Temporal cortex
c. Inner ear
90
The vestibular apparatus provides information necessary for:
a. Smell detection
b. Speech perception
c. Sense of equilibrium and coordinating head movements with eye and postural movements
d. Processing loudness
c. Sense of equilibrium and coordinating head movements with eye and postural movements
91
What do semicircular canals help you sense?
head rotation (spinning, turning, nodding)
92
Each semicircular canal detects:
a. Pitch differences
b. Loudness intensity
c. Movement in a different direction
d. Vibration of the oval window
c. Movement in a different direction
93
Otolith organs help detect:
a. Rotation
b. Sound waves
c. Head position and movement in a straight line
d. Pressure changes in the cochlea
c. Head position and movement in a straight line
94
The utricle detects:
horizontal acceleration/deceleration (like walking forward or stopping)
95
In the utricle, hairs bend backward when you start moving and forward when you:
a. Spin
b. Look down
c. Stop
d. Tilt your head sideways
c. Stop
96
The saccule detects:
vertical movement (jumping or riding an elevator)
also senses tilt away from horizontal (like sitting up from lying down)
97
What does bending of the hair cells in the saccule do?
bending of the hair cells = changes electrical activity = signals sent to the brain through the vestibulocochlear nerve (CN VIII)
98
Bending of hair cells in the otolith organs changes electrical activity and sends signals to the brain through the:
a. Facial nerve
b. Glossopharyngeal nerve
c. Vestibulocochlear nerve (CN VIII)
d. Trigeminal nerve
c. Vestibulocochlear nerve (CN VIII)
99
The otolith membrane detects:
a. Rotation only
b. Sound waves
c. Tilt and straight-line motion
d. Changes in endolymph pressure
c. Tilt and straight-line motion (in utricle and saccule)
100
What creates neural signals in the vestibular system?
a. Movement of the stapes
b. Movement of the basilar membrane
c. Hair cells bending because of fluid or otolith movement
d. Vibration of the tympanic membrane
c. Hair cells bending because of fluid or otolith movement
101
Neural signals from vestibular hair cells travel through which nerve?
Vestibulocochlear nerve
102
Vestibular signals travel to two key ears of the brain. What are they?
a. Temporal lobe and occipital lobe
b. Brainstem nuclei and hypothalamus
c. Vestibular nuclei in the brainstem and the cerebellum
d. Primary cortex and prefrontal cortex
c. Vestibular nuclei in the brainstem and the cerebellum
103
Which brain areas use vestibular information?
Vestibular nuclei in the brainstem and the cerebellum
104
Vestibular information helps you:
a. Increase auditory sensitivity
b. Maintain balance and posture
c. Improve smell detection
d. Increase blood pressure
b. Maintain balance and posture
105
Which function is coordinated using vestibular information?
a. Memory formation
b. Eye movements with head movements
c. Taste perception
d. Emotional responses
Eye movements with head movements (so your vision stays steady)
106
Vestibular signals allow you to sense:
a. Blood pH
b. Visual brightness
c. Your body’s motion and orientation in space
d. Pressure waves in the cochlea
c. Your body’s motion and orientation in space
107
Which of the following provides visual input to the vestibular nuclei?
a. Receptors in semicircular canals
b. Receptors in joints
c. Receptors in eyes
d. Receptors in skin
c. Receptors in eyes
108
Cutaneous input to the vestibular nuclei comes from:
a. Receptors in the eyes
b. Receptors in skin
c. Receptors in semicircular canals
d. Receptors in muscles only
b. Receptors in skin
109
Proprioceptive input is provided by:
a. Receptors in joints and muscles
b. Receptors in the cochlea
c. Receptors in the saccule only
d. Receptors in the retina
a. Receptors in joints and muscles
110
Vestibular input to the vestibular nuclei comes from:
a. Otolith organs and semicircular canals
b. Skin receptors
c. Eye receptors
d. Cochlear hair cells
a. Otolith organs and semicircular canals
111
The vestibular nuclei send output to motor neurons of limb and torso muscles to:
a. Increase loudness detection
b. Maintain balance and desired posture
c. Detect head rotation
d. Control smell
b. Maintain balance and desired posture
112
Output from the vestibular nuclei to motor neurons of external eye muscles allows for:
a. Balance of blood pressure
b. Control of eye movement
c. Pitch discrimination
d. Smell adaptation
b. Control of eye movement
113
Output from the vestibular nuclei to the CNS contributes to:
a. Perception of motion and orientation
b. Sound localization
c. Taste perception
d. Blood pressure regulation
a. Perception of motion and orientation
114
The cerebellum receives vestibular input for:
a. Coordinated processing
b. Smell interpretation
c. Hair cell regeneration
d. Sound frequency analysis
a. Coordinated processing
115
What do eyes detect?
Light (photoreceptors)
115
What do ears detect?
Mechanical vibration (mechanoreceptors)
116
What does taste and smell detect?
Chemicals (chemoreceptors)
117
The mechanism of taste is called?
Gustation
118
The mechanism of smell is called? STUDY
Olfaction
119
Gustatory is related to:
a. Smell only
b. Taste
c. Movement
d. Light detection
b. Taste
120
Taste buds detect which five tastes?
a. Sweet, sour, salty, bitter, umami
b. Sweet, salty, sour, spicy, minty
c. Bitter, metallic, sweet, oily, sour
d. Sour, savory, cold, spicy, salty
a. Sweet, sour, salty, bitter, umami
121
Taste receptors are:
a. Mechanoreceptors
b. Photoreceptors
c. Chemoreceptors
d. Thermoreceptors
c. Chemoreceptors
122
Taste buds consist of:
a. Only nerve cells
b. Only receptor cells
c. Taste receptor cells packaged with supporting cells
d. Only basal cells
c. Taste receptor cells packaged with supporting cells
123
How many taste buds do humans have?
10,000
124
Taste buds are located where?
oral cavity and throat
125
Where are taste buds most concentrated?
upper surface of tongue
126
Each taste bud contains around:
a. 5 receptor cells
b. 20 receptor cells
c. 50 receptor cells
d. 100 receptor cells
c. 50 receptor cells
127
Tastebuds have a lifespan of ___ days
10 days
128
Which cranial nerves synapse with taste buds?
Facial (VII)
Glossopharyngeal (IX)
Vagus (X)
129
Sensory signals travel through which structures to reach the cortical gustatory area?
brain stem and thalamus
130
Where is the cortical gustatory area located?
parietal lobe
131
The cortical gustatory area is adjacent to the:
a. Limbic system
b. “Tongue” region of the somatosensory cortex
c. Visual cortex
d. Basal nuclei
b. “Tongue” region of the somatosensory cortex
132
Gustatory pathways are primarily:
a. Crossed
b. Mixed
c. Uncrossed
d. Descending
c. Uncrossed
meaning the signals stay on the same side of the brain
133
From the brain stem, fibers project to which structures?
hypothalamus and limbic system
134
Projection to the hypothalamus and limbic system adds:
a. Reflexive swallowing responses
b. Motor control of tongue muscles
c. Affective dimensions (pleasant or unpleasant) and behavioural responses linked to taste and smell
d. Memory formation and visual processing
c. Affective dimensions (pleasant or unpleasant) and behavioural responses linked to taste and smell
135
Taste receptor cells are:
a. Modified neurons
b. Modified epithelial cells with many surface folds (microvilli)
c. Only nerve endings
d. Muscle cells
b. Modified epithelial cells with many surface folds (microvilli)
136
Microvilli protrude slightly through the:
a. Tongue papilla
b. Taste pore
c. Salivary duct
d. Oral cavity wall
b. Taste pore
137
Microvilli greatly increase the surface area exposed to:'
a. Air
b. Chemicals in blood
c. The contents of the mouth
d. Light
c. The contents of the mouth
138
Receptor sites on the microvilli bind selectively with:
a. Sound waves
b. Odours
c. Taste-provoking chemicals
d. Temperature changes
c. Taste-provoking chemicals
aka tastants
139
Tastants (liquids or solids dissolved in saliva) binding causes:
a. Hyperpolarization of the receptor
b. Closing of the taste pore
c. Changes ionic channels → depolarizing receptor potential → action
d. No change in receptor activity
c. Changes ionic channels → depolarizing receptor potential → action
140
Taste receptor cells have a short lifespan because:
a. They cannot divide
b. They are exposed to strong chemicals
c. They are not innervated
d. They are replaced by nerve fibres
b. They are exposed to strong chemicals
141
Surrounding epithelial cells continually differentiate into:
a. Only receptor cells
b. Only basal cells
c. Supporting cells, then into new receptor cells
d. Muscle fibres
c. Supporting cells, then into new receptor cells
142
Each taste receptor cell is capable of responding to:
a. Only one primary taste
b. Three primary tastes
c. All five primary tastes: salty, sour, sweet, bitter, and umami
d. Only umami and sweet
c. All five primary tastes: salty, sour, sweet, bitter, and umami
143
The process of surrounding epithelial cells forming new receptor cells ensures:
a. Permanent cell damage
b. Constant renewal
c. Loss of taste sensations
d. Decreased sensitivity
b. Constant renewal
144
The primary tastes include salty, sour, sweet, bitter, and:
a. Mint
b. Spicy
c. Metallic
d. Umami
d. Umami (recently added)
145
Umami is described as:
a. Sour
b. Meaty or savoury taste
c. Bitter
d. Metallic taste
b. Meaty or savoury taste
146
Every receptor cell shows a stronger or “preferential” response to:
a. All tastes equally
b. One specific taste modality
c. Only bitter and sour
d. Only salty and sweet
b. One specific taste modality
147
Some cells respond most strongly to sweet substances, while others respond better to:
a. Salty or sour ones
b. Bitter only
c. Umami only
d. Spicy foods
a. Salty or sour ones
148
Flavor is recognized by the brain from:
a. Individual receptor cell types
b. Combined activity patterns of many taste buds
c. Only bitter receptor activation
d. Pressure and sound waves
b. Combined activity patterns of many taste buds
149
All tastes are combinations of:
a. Hundreds of taste categories
b. Three taste types
c. Five primary tastes
d. Only sweet, salty, and sour
c. Five primary tastes
150
Combined activity patterns of taste buds allow detection of:
a. Five flavours
b. Ten flavours
c. Hundreds of flavours
d. Thousands of flavours
d. Thousands of flavours
151
Sour taste is caused by:
a. Sugars
b. Salts
c. Acids containing a free hydrogen ion (H⁺)
d. Amino acids
c. Acids containing a free hydrogen ion (H⁺)
152
Citric acid in lemons produces:
a. A salty taste
b. A bitter taste
c. A sweet taste
d. A distinct sour taste
d. A distinct sour taste
153
H⁺ blocks which channels in the receptor cell membrane?
a. Na⁺ channels
b. Ca²⁺ channels
c. K⁺ channels
d. Cl⁻ channels
c. K⁺ channels
154
Blocking K⁺ channels reduces:
a. Passive Na⁺ movement into the cell
b. Passive K⁺ movement out of the cell
c. Ca²⁺ entry
d. Release of neurotransmitter
b. Passive K⁺ movement out of the cell
155
Reducing passive K⁺ movement out of the cell decreases:
a. Internal negativity
b. Internal positivity
c. Membrane thickness
d. Receptor number
a. Internal negativity
= a depolarizing receptor potential
156
Decreasing internal negativity produces:
a. Hyperpolarization
b. No change in potential
c. Cell death
d. A depolarizing receptor potential
d. A depolarizing receptor potential
157
What stimulates a salty taste?
chemical salts, NaCl (table salt)
158
Which ions enter channels in the receptor cell membrane for salty taste?
a. K⁺
b. H⁺
c. Na⁺ ions
d. Ca²⁺
c. Na⁺ ions
159
Na⁺ ions enter through:
a. K⁺ channels
b. Ca²⁺ pumps
c. Specialized Na⁺ channels in the receptor cell membrane
d. Chloride channels
c. Specialized Na⁺ channels in the receptor cell membrane
160
161
Entry of Na⁺ reduces:
a. Membrane permeability
b. Internal positivity
c. Internal negativity
d. Na⁺ concentration in saliva
Correct answer: c
c. Internal negativity
162
Reducing internal negativity causes:
a. Hyperpolarization
b. Depolarization of the receptor cell
c. Closure of Na⁺ channels
d. No change in membrane potential
b. Depolarization of the receptor cell
163
Taste receptor cells produce a depolarizing receptor potential in response to:
a. Odours
b. Sound waves
c. Tastants
d. Light
c. Tastants
164
Sweet taste is triggered by what?
Glucose and other molecules with similar shapes (aspartame, saccharin, Sucralose)
165
Glucose binds to sweet receptors on the taste cell and:
a. Opens Na⁺ channels
b. Opens Ca²⁺ channels
c. Closes K⁺ channels, trapping K⁺ inside
d. Increases passive K⁺ efflux
c. Closes K⁺ channels, trapping K⁺ inside
166
Closing K⁺ channels causes the cell to become:
a. More negative → hyperpolarized
b. Less negative → depolarized
c. Unchanged
d. Permeable only to Na⁺
b. Less negative → depolarized
167
The depolarization produced by closing K⁺ channels:
a. Blocks taste signaling
b. Produces a receptor potential that signals sweetness to the brain
c. Opens chloride channels
d. Reduces taste sensitivity
b. Produces a receptor potential that signals sweetness to the brain
168
From an evolutionary view, sweetness encourages us to seek:
a. Water-rich foods
b. Energy-rich foods
c. Bitter foods
d. Sour foods
b. Energy-rich foods
169
Bitter cells have how many receptors?
50-100 receptors
170
Each bitter receptor is tuned to:
a. Only sweet molecules
b. Different bitter molecules
c. Only salty molecules
d. A single toxin
b. Different bitter molecules
171
A single taste cell can respond to:
a. Only one bitter substance
b. Many unrelated bitter substances
c. Only one type of alkaloid
d. Only caffeine
b. Many unrelated bitter substances
172
Detecting many bitter substances allows:
a. Detection of sweetness
b. Broad detection of toxins
c. Enhanced smell sensitivity
d. Detection of sour foods
b. Broad detection of toxins
173
Bitter taste cells are triggered by alkaloids such as:
a. Glucose, sucrose
b. Citric acid, ascorbic acid
c. Caffeine, nicotine, strychnine, morphine
d. Sodium chloride
c. Caffeine, nicotine, strychnine, morphine
174
Bitter taste serves as a defense mechanism to prevent:
a. Digestion
b. Vision problems
c. Ingestion of harmful or poisonous chemicals
d. Water loss
c. Ingestion of harmful or poisonous chemicals
175
Bitter molecules bind to special receptors and activate the G protein:
a. Gustducin
b. Transducin
c. Rhodopsin
d. Opsin
a. Gustducin
176
Activation of gustducin turns on:
a. Na⁺ channels
b. PLC (phospholipase C)
c. Ca²⁺ pumps
d. K⁺ leak channels
b. PLC (phospholipase C)
177
PLC activation causes:
a. K⁺ to leave the cell
b. Release of calcium inside the cell
c. Opening of Na⁺ channels
d. Hyperpolarization
b. Release of calcium inside the cell
178
Release of calcium inside the cell causes ion channels to open, leading to:'
a. No change in potential
b. Hyperpolarization
c. Depolarization (less negative)
d. Cell shrinkage
c. Depolarization (less negative)
179
Depolarization creates a receptor potential that:
a. Blocks taste signaling
b. Signals to the brain that the taste is bitter
c. Triggers sour taste perception
d. Prevents gustation
b. Signals to the brain that the taste is bitter
180
Umami taste is ___
meaty or savoury
181
Umami is triggered by amino acids, especially:
a. Lysine
b. Glutamate
c. Tryptophan
d. Serine
b. Glutamate
182
Glutamate binds to a:
a. Sodium channel
b. Potassium pump
c. G protein-coupled receptor
d. Calcium transporter
c. G protein-coupled receptor
183
Binding of glutamate activates:
a. A first-messenger system
b. A second-messenger system inside the taste cell
c. Direct ion flow without signaling
d. Hyperpolarization only
b. A second-messenger system inside the taste cell
184
Activation of the second-messenger system creates:
a. No electrical change
b. A receptor potential
c. A refractory period
d. An action potential directly
b. A receptor potential
185
Taste perception is determined by:
Taste receptors
Smell (odour) receptors
Temperature
Texture of the food
Psychological factors
186
When you have a cold, swollen nasal passages reduce your sense of smell. As a result:
a. Your sense of touch decreases
b. Your vision becomes blurry
c. Your ability to taste also decreases
d. Your temperature sensitivity increases
c. Your ability to taste also decreases
187
Psychological factors influencing taste include:
a. Hormone levels
b. Past experiences and emotional associations with particular foods
c. Neuron density
d. Cranial nerve fatigue
b. Past experiences and emotional associations with particular foods
188
A patient reports that food “has no taste” after recovering from a bad cold. What sensory system was most likely affected?
a. Taste receptors only
b. Smell (odour) receptors
c. Photoreceptors
d. Vestibular receptors
b. Smell (odour) receptors
swollen nasal passages reduce smell, ability to taste also decreases
189
Damage to the gustatory cortex in the parietal lobe would most likely cause:
a. Loss of balance and posture
b. Difficulty integrating taste signals into perception and enjoyment of food
c. Loss of hearing
d. Inability to detect temperature of foods
b. Difficulty integrating taste signals into perception and enjoyment of food
190
A patient undergoing chemotherapy says food “tastes metallic” or “strange.” What factor could explain this change?
a. Temperature of food
b. Psychological factors only
c. Damage or alteration to taste receptors and supporting cells
d. Reduced vestibular input
c. Damage or alteration to taste receptors and supporting cells
Taste receptors have a short lifespan and undergo constant renewal; chemo can disrupt this process and alter perception.
191
What is the function of the taste pore?
a. To regenerate receptor cells
b. Opening where chemicals in food contact receptor cells
c. Produces saliva
d. Houses cranial nerves
b. Opening where chemicals in food contact receptor cells
192
Which statement describes receptor cells in taste buds?
a. They are neurons that fire directly
b. Modified epithelial cells with microvilli containing receptor sites for tastants
c. Cells that secrete digestive enzymes
d. Supporting cells that regenerate basal cells
b. Modified epithelial cells with microvilli containing receptor sites for tastants
193
What is the role of supporting and basal cells in taste buds?
a. Conduct action potentials
b. Help maintain and regenerate receptor cells
c. Detect odorants
d. Produce neurotransmitters
b. Help maintain and regenerate receptor cells
194
Binding of a tastant to receptor sites directly causes:
a. Hyperpolarization of the receptor cell
b. Opening of Ca²⁺ channels in the thalamus
c. A depolarizing receptor potential
d. Production of saliva
c. A depolarizing receptor potential
195
What causes neurotransmitter release from the receptor cell?
a. Ion efflux from the brainstem
b. Depolarizing receptor potential
c. Saliva breakdown of tastants
d. Pressure changes on microvilli
b. Depolarizing receptor potential
196
Neurotransmitters released by taste receptor cells initiate:
a. Action potentials in afferent nerve fibres
b. Thalamic secretion of hormones
c. Motor responses in the tongue
d. Olfactory receptor activation
a. Action potentials in afferent nerve fibres
197
Which cranial nerves carry taste information?
a. V, VII, and XI
b. VII, IX, and X
c. III, IV, and VI
d. I, II, and VIII
b. Facial VII, Glossopharyngeal IX, Vagus X
198
Taste signals travel from the taste buds through which pathway?
a. Brainstem → cerebellum → cortex
b. Solitary nucleus → thalamus → gustatory cortex
c. Olfactory bulb → thalamus → hypothalamus
d. Retina → midbrain → cortex
b. Solitary nucleus → thalamus → gustatory cortex
199
Where is the gustatory cortex located?
a. Occipital lobe
b. Parietal lobe (in the insula)
c. Temporal lobe
d. Frontal lobe
b. Parietal lobe (in the insula)
200
What is the olfactory mucosa (smell)? STUDY
a. A muscle layer controlling airflow
b. A 3 cm² patch of mucosa in the ceiling of the nasal cavity containing olfactory cells
c. A lymphatic patch near the pharynx
d. A bone-lined cavity where odor molecules are stored
b. A 3 cm² patch of mucosa in the ceiling of the nasal cavity containing olfactory cells
201
Olfactory receptor cells are: STUDY
a. Supporting cells that secrete mucus
b. Basal epithelial cells
c. Afferent neurons whose receptor portion lies in the olfactory mucosa
d. Motor neurons involved in breathing
c. Afferent neurons whose receptor portion lies in the olfactory mucosa
202
The axons of olfactory receptor cells collectively form: STUDY
a. The trigeminal nerve
b. The olfactory nerve
c. The facial nerve
d. The glossopharyngeal nerve
b. The olfactory nerve
203
What is the function of supporting cells in the olfactory mucosa? STUDY
a. Generate action potentials
b. Secrete mucus that coats the nasal passages
c. Replace damaged neurons
d. Transport odorants to the brain
b. Secrete mucus that coats the nasal passages
204
Basal cells in the olfactory mucosa are: STUDY
a. Immune cells that detect pathogens
b. Precursor cells for new olfactory receptor cells
c. Neurons responsible for odor interpretation
d. Glands that produce mucus
b. Precursor cells for new olfactory receptor cells
205
How often are olfactory receptor cells replaced? STUDY
a. Every 10 days
b. About every two months
c. Every year
d. Every 24 hours
b. About every two months
206
What do olfactory cells have on their surface? STUDY
a. Microvilli for absorbing odorants
b. Cilia with binding sites for odor molecules
c. Hair cells that detect sound waves
d. Pores that secrete mucus
b. Cilia with binding sites for odor molecules
207
Odorants must first do what before attaching to olfactory receptors? STUDY
a. Be filtered by the sinuses
b. Dissolve in mucus
c. Be heated by airflow
d. Be broken down by enzymes
b. Dissolve in mucus
208
During normal breathing, how many odor molecules reach the receptors?
a. A large number
b. None
c. Few odor molecules
d. Only molecules from the mouth
c. Few odor molecules
209
What effect does sniffing have?
a. It decreases odor detection
b. It traps odorants in mucus
c. It pulls more air upward, bringing more odorants to the receptors
d. It blocks airflow to the olfactory bulb
c. It pulls more air upward, bringing more odorants to the receptors
210
How are smell and taste linked?
a. They use the same receptor cells
b. Taste buds send signals to the olfactory bulb
c. Odor molecules can reach the nose from the mouth through the pharynx
d. Smell receptors detect taste chemicals
c. Odor molecules can reach the nose from the mouth through the pharynx
211
What are odorants?
a. Molecules in food that activate taste buds
b. Molecules in the air that stimulate smell receptors
c. Chemicals secreted by the olfactory mucosa
d. Substances that dissolve in saliva
b. Molecules in the air that stimulate smell receptors
212
To be smelled, a substance must be sufficiently:
a. Acidic
b. Concentrated
c. Volatile
d. Sticky
c. Volatile (easily vaporized)
so molecules can enter the nose in the inspired air
213
Which allows an odorant to dissolve in the mucus that coats the olfactory mucosa? STUDY
a. Oil solubility
b. Water solubility
c. High viscosity
d. Chemical neutralization
b. Water solubility
214
A substance will NOT be smelled if it is:
a. Volatile and water soluble
b. Easily vaporized
c. Unable to dissolve in mucus
d. Able to enter the inspired air
c. Unable to dissolve in mucus
215
Approximately how many olfactory receptors does the human nose contain?
a. 500,000
b. 1 million
c. 5 million
d. 10 million
c. 5 million of about 1000 types
216
Each olfactory receptor detects: STUDY
a. All components of an odor
b. Only one specific component
c. Only dangerous odors
d. Only pleasant odors
b. Only one specific component (not the whole scent)
217
A single olfactory receptor may respond to: STUDY
a. Only one specific odor mixture
b. All scent molecules equally
c. A shared component found in different odours
d. Odours only when taste buds are also activated
c. A shared component found in different odours
218
Odour detection is similar to which of the following systems?
a. Rod cells for night vision
b. Three cone types for colour vision
c. Two types of photopigments
d. Retinal ganglion cell mapping
b. Three cone types for colour vision and five primary tastes detected by taste buds
219
What happens first in olfactory signal transmission? STUDY
a. Sodium channels open spontaneously
b. A smell molecule binds to a receptor inside the nose
c. The nerve fires due to high concentration
d. The cell repolarizes
b. A smell molecule binds to a receptor inside the nose
220
Binding of a smell molecule activates which of the following?
a. A calcium pump
b. A chloride channel
c. A G protein
d. A voltage-gated K⁺ channel
c. A G protein
221
Activation of the G protein leads to:
a. Closing of Na⁺ channels
b. Opening of Na⁺ channels
c. Opening of K⁺ leak channels
d. Immediate neurotransmitter release
b. Opening of Na⁺ channels
222
When Na⁺ enters the olfactory receptor cell, the cell becomes: STUDY B
a. More negative (hyperpolarized)
b. Neutral
c. Less negative (depolarized)
d. Unable to fire
c. Less negative (depolarized)
223
What effect do stronger smells (higher concentration) have?
a. They make the nerve fire slower
b. They block the G protein
c. They reduce depolarization
d. They make the nerve fire faster
d. They make the nerve fire faster
224
Receptor Activation and Signal Transmission
* A smell molecule binds to a receptor inside the nose.
* This turns on a G protein, which starts a chain reaction inside the cell.
* The reaction opens Na⁺ channels, letting sodium in.
* The cell becomes less negative (depolarized), creating a signal.
* Stronger smells (concentration )make the nerve fire faster
225
Where do olfactory receptor fibres pass to reach the brain?
a) Through the semicircular canals
b) Through tiny bone openings to the olfactory bulb
c) Through the thalamus
d) Through the optic chiasm
b) Through tiny bone openings to the olfactory bulb
226
The olfactory bulb has layered cells similar to which structure?
a) Auditory cortex
b) Retina
c) Cochlea
d) Basilar membrane
b) Retina
227
How many olfactory bulbs does the brain have?
a) One central bulb
b) Three bulbs (one in each lobe)
c) Two bulbs, one on each side of the brain
d) Four bulbs
c) Two bulbs, one on each side of the brain
228
What does each glomerulus receive?
a) Signals from many unrelated odor molecules
b) Signals from one specific odor component
c) Sound input from the cochlea
d) Signals from taste buds
b) Signals from one specific odor component
229
What is the role of a glomerulus?
a) Detects light intensity
b) Acts as a “smell file” that sorts odor components
c) Stores memories
d) Generates action potentials
b) Acts as a “smell file” that sorts odor components
230
What do mitral cells do?
a) Produce mucus to trap odorants
b) Regenerate receptor cells
c) Refine signals from glomeruli and send them to higher brain areas
d) Detect temperature
c) Refine signals from glomeruli and send them to higher brain areas
231
What does the subcortical olfactory route link smell to?
a) Visual processing
b) Motor coordination
c) Emotion and behaviour
d) Balance and posture
c) Emotion and behaviour (limbic system and hypothalamus)
232
The cortical route sends smell information through the thalamus to which area?
a) Gustatory cortex
b) Olfactory cortex
c) Auditory cortex
d) Somatosensory cortex
b) Olfactory cortex for conscious smell perception
233
Each odorant activates:
a) Only one receptor and one glomerulus
b) Multiple receptors and glomeruli
c) Only a single glomerulus
d) Only supporting cells
b) Multiple receptors and glomeruli
234
How does the brain distinguish different scents?
a) By odorant temperature
b) By the number of odor molecules inhaled
c) By unique patterns of glomeruli activation
d) By the location of the odorant on the tongue
c) By unique patterns of glomeruli activation
235
Humans can identify approximately:
a) 500 odours
b) 1,000 odours
c) 10,000 different odours
d) 1 million odours
c) 10,000 different odours
236
Why is methyl mercaptan (garlic odour) added to natural gas for safety?
a) It burns more efficiently
b) It prevents gas leaks
c) It produces a detectable odour even at extremely low concentrations
d) It neutralizes toxic fumes
c) It produces a detectable odour even at extremely low concentrations
we can detect it at 1 molecule per 50 billion in air
237
How many olfactory receptors do humans have?
5 million
238
How many olfactory receptors do dogs have?
4 billion
239
How much stronger is a dogs sense of smell compared to a human?
hundreds of times stronger
240
The olfactory system is described as STUDY
a) Insensitive and slow to respond
b) Highly sensitive and discriminating
c) Only adaptive, not discriminating
d) Mostly insensitive to weak odours
b) highly sensitive and discriminating, yet highly adaptive
241
What happens to sensitivity with continued exposure to a new odour? STUDY
a) It increases
b) It stays constant
c) It decreases rapidly
d) It becomes more accurate
c) It decreases rapidly
242
Where are the enzymes that neutralize harmful odour molecules located? STUDY
a) Olfactory bulb
b) Olfactory mucosa
c) Thalamus
d) Cerebral cortex
b) Olfactory mucosa
243
The enzymes in the olfactory mucosa: STUDY
a) Increase odour sensitivity
b) Store odours for long-term memory
c) Clear away odour molecules and neutralize harmful chemicals
d) Block odorants from reaching receptors
c) Clear away odour molecules and neutralize harmful chemicals
244
The detoxifying enzymes in the olfactory mucosa are similar to enzymes in the:
STUDY
a) Pancreas
b) Lungs
c) Liver
d) Kidneys
c) Liver
245
Why is detoxification important in the olfactory system? STUDY
a) Because it prevents taste adaptation
b) Because of the direct connection between the nasal cavity and brain tissue
c) Because smell neurons cannot regenerate
d) Because odorants would damage the tongue otherwise
b) Because of the direct connection between the nasal cavity and brain tissue
246
The vomeronasal organ was once thought to be:
a) Overdeveloped in humans
b) Nonexistent in humans
c) Only present in aquatic mammals
d) A part of the olfactory cortex
b) Nonexistent in humans
247
Where is the human VNO located?
a) On the olfactory bulb
b) Deep in the frontal sinus
c) About 15 mm inside the nose on the nasal septum
d) Behind the soft palate
c) About 15 mm inside the nose on the nasal septum
248
The vomeronasal organ detects:
a) Tastants
b) Photons
c) Pheromones
d) Volatile odorants only
c) Pheromones
249
Pheromones are released by:
a) Sebaceous glands only
b) Apocrine glands in armpits and perineal regions
c) Salivary glands
d) Mucus glands in the nasal cavity
b) Apocrine glands in armpits and perineal regions
250
In animals, pheromone binding activates:
a) The visual cortex
b) The cerebellum
c) The limbic system
d) The spinal cord
c) The limbic system
251
In animals, the VNO is known as the “sexual nose” because it:
a) Controls breathing rate
b) Helps identify mates and social status
c) Detects food flavours
d) Increases olfactory receptor regeneration
b) Helps identify mates and social status
252
The role of the VNO in humans is:
a) Well understood and essential
b) Uncertain
c) Only involved in taste
d) Used exclusively for detecting danger
b) Uncertain
253
Some suggest the VNO in humans may influence:
a) Hunger
b) Body temperature
c) “Chemistry” or attraction
d) Pain perception
c) “Chemistry” or attraction
254
The autonomic nervous system (ANS) is the:
a) Voluntary branch of the PNS
b) Involuntary branch of the PNS
c) Sensory branch of the CNS
d) Motor branch of the CNS
b) Involuntary branch of the PNS
255
The autonomic nervous system innervates:
a) Only skeletal muscle
b) Only cardiac muscle
c) Cardiac muscle, smooth muscle, most exocrine glands, some endocrine glands, and adipose tissue
d) Only smooth muscle and skeletal muscle
c) Cardiac muscle, smooth muscle, most exocrine glands, some endocrine glands, and adipose tissue
256
The somatic nervous system is:
a) Involuntary
b) Subject to voluntary control
c) Part of the endocrine system
d) Responsible for gland secretion
b) Subject to voluntary control
257
The somatic nervous system innervates:
a) Smooth muscle
b) Cardiac muscle
c) Skeletal muscle
d) Exocrine glands
c) Skeletal muscle
258
Explain the body's flight-or-fight response
Unnecessary functions reduced and energy diverted to other functions vital to survival
259
Efferent neurons originate in the:
a) Thalamus
b) Motor cortex
c) Cerebellum
d) Hypothalamus
b) Motor cortex
260
Efferent neurons descend through the brainstem, including the medulla oblongata, and the:
a) Basal nuclei
b) Cerebral aqueduct
c) Spinal cord
d) Limbic system
c) Spinal cord to synapse with lower motor neurons in the gray matter.
261
What are the two neurotransmitters used in the autonomic nervous system?
a) Dopamine and serotonin
b) Acetylcholine and norepinephrine
c) GABA and glutamate
d) Serotonin and histamine
b) Acetylcholine (ACh) and norepinephrine (NE)
262
The neurotransmitters Acetylcholine and norepinephrine cause diverse effects such as:
a) Bone growth and immune activation
b) Salivary secretion, bladder contraction, and voluntary movements
c) Hearing and balance
d) Vision and pupil dilation only
b) Salivary secretion, bladder contraction, and voluntary movements
263
The efferent division has two main branches:
a) CNS and PNS
b) Parasympathetic and sympathetic
c) Somatic nervous system & autonomic nervous system
d) Sensory and motor
Somatic nervous system & autonomic nervous system
264
The autonomic nervous system (ANS) provides:
a) Voluntary control of skeletal muscles
b) Involuntary control of cardiac muscle, smooth muscle, and glands
c) Sensory detection of touch
d) Reflex control only
b) Involuntary control of cardiac muscle, smooth muscle, and glands
265
The somatic nervous system (ANS) provides:
a) Voluntary control of skeletal muscles
b) Involuntary control of cardiac muscle, smooth muscle, and glands
c) Sensory detection of touch
d) Reflex control only
a) Voluntary control of skeletal muscles
266
Efferent output maintains homeostasis and responds to:
a) Smell
b) Stress
c) Light
d) Sound
b) Stress (e.g., the fight-or-flight response)
267
When facing sudden danger, the body activates the:
a) Parasympathetic nervous system
b) Somatic nervous system
c) Enteric nervous system
d) Sympathetic nervous system
d) Sympathetic nervous system
268
The sympathetic nervous system activates to:
a) Improve digestion
b) Prepare for survival
c) Promote sleep
d) Increase urine production
b) Prepare for survival
269
Which changes occur during the fight-or-flight response?
a) Heart rate, blood pressure, and breathing decrease
b) Heart rate, blood pressure, and breathing increase
c) Heart rate decreases while breathing increases
d) No change occurs
b) Heart rate, blood pressure, and breathing increase
270
During the fight-or-flight response:
a) Energy stores are saved for later
b) Energy stores are released for use by skeletal muscles
c) Energy is diverted to digestion
d) Energy is stored as fat
b) Energy stores are released for use by skeletal muscles
271
During the fight-or-flight response, blood flow decreases to:
a) Muscles
b) Heart
c) Digestive organs
d) Lungs
c) Digestive organs
272
During the fight-or-flight response, blood flow increases to:
a) Skin only
b) Muscles, heart, lungs, and skin
c) Digestive tract only
d) Brain only
b) Muscles, heart, lungs, and skin
273
Which hormones are released during the fight-or-flight response?
a) Dopamine and serotonin
b) Epinephrine and norepinephrine
c) GABA and glutamate
d) Acetylcholine and histamine
b) Epinephrine and norepinephrine
274
Epinephrine and norepinephrine are released to:
a) Slow heart rate and increase digestion
b) Boost heart rate, energy, and reduce pain if needed
c) Increase urine and saliva production
d) Improve memory formation
b) Boost heart rate, energy, and reduce pain if needed
275
The autonomic nervous system controls:
a) Skeletal muscles only
b) Smooth muscles, glands, and the heart
c) Bones and tendons
d) Only the gastrointestinal tract
b) Smooth muscles, glands, and the heart
276
What are the two divisions of the autonomic nervous system?
sympathetic (fight or flight)
parasympathetic (rest and digest)
277
The sympathetic division:
a) Calms the body
b) Activates the body (fight-or-flight)
c) Controls only digestion
d) Controls voluntary movement
b) Activates the body (fight-or-flight)
278
The parasympathetic division:
a) Activates the body
b) Calms the body (rest-and-digest)
c) Controls skeletal muscles
d) Is the same as the enteric system
b) Calms the body (rest-and-digest)
279
The enteric system regulates:
a) Vision and hearing
b) Digestion
c) Skeletal muscle contraction
d) Breathing rate
b) Digestion (motility, secretion, and blood flow in the GI tract)
280
The autonomic nervous system is controlled by:
a) Cerebellum and pons only
b) Hypothalamus, brain stem, and spinal cord
c) Motor cortex only
d) Basal nuclei
b) Hypothalamus, brain stem, and spinal cord
281
The cortex processes sensory inputs and sends signals to:
a) Hippocampus and cerebellum
b) Hypothalamus and medulla for integration
c) Pituitary gland
d) Frontal lobe
b) Hypothalamus and medulla for integration
282
ANS pathways carry efferent (outgoing) signals to organs via:
a) Only somatic nerves
b) Sympathetic and parasympathetic nerves
c) Cranial nerve II only
d) Spinal reflex arcs
b) Sympathetic and parasympathetic nerves
283
Central regulators of the ANS also coordinate:
a) Sleep cycles only
b) Stress response, reproduction, and thermoregulation
c) Vision and hearing
d) Language processing
b) Stress response, reproduction, and thermoregulation
284
Each autonomic pathway:
a) Has one long neuron chain
b) Extends from CNS to organ and has a two-neuron chain
c) Uses only spinal reflexes
d) Has no synapses
b) Extends from CNS to organ and has a two-neuron chain
285
A preganglionic fibre has its cell body in the:
a) Ganglion
b) CNS
c) Effector organ
d) Skeletal muscle
b) CNS
285
The preganglionic axon synapses with the second neuron in the:
a) Cortex
b) Effector organ
c) Ganglion
d) Cerebellum
c) Ganglion
286
A postganglionic fibre has its cell body in the:
a) CNS
b) Effector organ
c) Ganglion
d) Medulla
c) Ganglion
287
The postganglionic fibre innervates the:
a) Spinal cord
b) Effector organ
c) Brainstem
d) Preganglionic neuron
b) Effector organ (e.g., smooth muscle, heart)
288
Where does sympathetic division originate?
Thoracic and lumbar spinal cord
289
Short preganglionic fibres in the sympathetic division:
a) Synapse in terminal ganglia
b) Synapse in sympathetic ganglion chain near the spinal cord
c) Have no synapse
d) Synapse directly on organ cells
b) Synapse in sympathetic ganglion chain near the spinal cord
290
Long postganglionic fibres in the sympathetic division:
a) Innervate effector organs
b) Only innervate skeletal muscle
c) Are located in the CNS
d) Synapse in the brainstem
a) Innervate effector organs
291
Some sympathetic preganglionic fibres pass through to collateral ganglia, which are located:
a) In the brain
b) In the spinal cord
c) Halfway to the organs
d) In the effector organs
c) Halfway to the organs
292
The parasympathetic division originates from the:
a) Thoracic spinal cord
b) Lumbar spinal cord
c) Cranial (brain) and sacral spinal cord regions
d) Cervical spinal nerves
c) Cranial (brain) and sacral spinal cord regions
293
Long preganglionic fibres in the parasympathetic division:
a) Synapse immediately near the spinal cord
b) Reach terminal ganglia in or near the effector organs
c) Do not synapse
d) Synapse only in the sympathetic chain
b) Reach terminal ganglia in or near the effector organs
294
Short parasympathetic postganglionic fibres:
a) Act directly on organ cells
b) Travel long distances
c) Are located in the spinal cord
d) Synapse in the sympathetic chain
a) Act directly on organ cells
295
Preganglionic fibres (both sympathetic & parasympathetic) release:
a) Norepinephrine
b) Dopamine
c) Acetylcholine
d) Serotonin
c) Acetylcholine = they are all cholinergic
296
Parasympathetic postganglionic fibres release:
a) Norepinephrine
b) Acetylcholine
c) Epinephrine
d) Serotonin
b) Acetylcholine = called cholinergic fibres
297
Sympathetic postganglionic fibres release:
a) Acetylcholine
b) Norepinephrine
c) Dopamine
d) Serotonin
b) Norepinephrine (noradrenaline) = called Adrenergic fibres
298
Postganglionic fibres have many swellings (varicosities) which allow them to:
a) Release neurotransmitters only at one terminal
b) Release neurotransmitters over a wide area, affecting entire organs rather than single cells
c) Prevent neurotransmitter release
d) Release hormones into the bloodstream
b) Release neurotransmitters over a wide area, affecting entire organs rather than single cells
299
Smooth and cardiac muscle cells are electrically linked by gap junctions, allowing the response to:
a) Stop immediately
b) Spread across the tissue
c) Affect only one cell
d) Become weaker
b) Spread across the tissue
300
Acetylcholine is released from:
a) Most sympathetic postganglionic terminals
b) All preganglionic terminals of the autonomic nervous system
c) Adrenal medulla
d) Central nervous system
b) All preganglionic terminals of the autonomic nervous system
301
Which terminals release Acetylcholine?
a) All parasympathetic postganglionic terminals
b) Most sympathetic postganglionic terminals
c) Adrenal medulla
d) CNS only
a) All parasympathetic postganglionic terminals
302
Sympathetic postganglionic terminals that release Acetylcholine are located at:
a) The heart
b) Sweat glands and some blood vessels in skeletal muscle
c) Adrenal medulla
d) Lungs
b) Sweat glands and some blood vessels in skeletal muscle
303
Terminals of efferent neurons supplying skeletal muscle (motor neurons) release:
a) Norepinephrine
b) Acetylcholine
c) Epinephrine
d) Dopamine
b) Acetylcholine
304
Norepinephrine is released from:
a) All preganglionic autonomic fibres
b) Most sympathetic postganglionic terminals
c) Parasympathetic postganglionic terminals
d) Motor neurons
b) Most sympathetic postganglionic terminals
305
Which structure releases norepinephrine?
a) Sweat glands
b) Adrenal medulla
c) Parasympathetic ganglia
d) Motor end plates
b) Adrenal medulla
306
Norepinephrine is also released in the:
a) Parasympathetic nervous system
b) Central nervous system
c) Neuromuscular junction
d) Sweat glands
b) Central nervous system
307
What is the effect of Sympathetic Stimulation on the heart?
a. Decreased rate and force (atria only)
b. Increased rate and force (whole heart)
c. No change
d. Only increases atrial contraction
b. Increased rate and force (whole heart)
308
What is the Parasympathetic Stimulation effect on the heart?
a. Increased rate and force (whole heart)
b. Increased rate only
c. Decreased rate and force (atria only)
d. Decreased rate and force (entire heart)
c. Decreased rate and force (atria only)
309
What is the Sympathetic Stimulation effect on blood vessels?
a. Dilated
b. Constricted
c. Relaxed
d. No effect
b. Constricted
310
Parasympathetic Stimulation dilates which blood vessels?
a. Cerebral arteries
b. All systemic vessels
c. Vessels of arms and legs
d. Penis and clitoris only
d. Penis and clitoris only
311
What is the Sympathetic Stimulation effect on the bronchioles?
a. Constricted
b. Dilated
c. No effect
d. Closed completely
b. Dilated
312
What is the Parasympathetic Stimulation effect on bronchioles?
a. Dilated
b. Constricted
c. No effect
d. Increased airflow
b. Constricted
313
What happens to mucus secretion with Sympathetic Stimulation?
a. Stimulated
b. Inhibited
c. No effect
d. Thickened
b. Inhibited
314
What happens to mucus secretion with Parasympathetic Stimulation?
a. Stimulated
b. Inhibited
c. No effect
d. Dried out
a. Stimulated
315
Sympathetic effect on digestive motility is:
a. Increased
b. Decreased
c. No effect
d. Variable
b. Decreased
316
Parasympathetic effect on digestive motility:
a. Decreased
b. Increased
c. No effect
d. Stops completely
b. Increased
317
Sympathetic effect on digestive sphincters:
a. Relaxed
b. Dilated
c. Constricted to prevent forward movement of contents
d. No effect
c. Constricted to prevent forward movement of contents
318
Parasympathetic effect on digestive sphincters:
a. Constricted
b. Relaxed to permit forward movement of contents
c. No effect
d. Closed fully
b. Relaxed to permit forward movement of contents
319
Sympathetic effect on digestive secretions:
a. Stimulated
b. Inhibited
c. No effect
d. Increased dramatically
b. Inhibited
320
Parasympathetic effect on digestive secretions:
a. Inhibited
b. Stimulated
c. No effect
d. Reduced
b. Stimulated
321
Sympathetic effect on urinary bladder:
a. Contracted
b. Relaxed
c. Stimulated
d. Emptying
b. Relaxed
322
Parasympathetic effect on urinary bladder:
a. Relaxed
b. Contracted (emptying)
c. No effect
d. Dilated
b. Contracted (emptying)
323
Sympathetic effect on pupil:
a. Constricted
b. Dilated for far vision adjustment
c. Normal
d. Closed
b. Dilated for far vision adjustment
324
Parasympathetic effect on pupil:
a. Dilated
b. Constricted for near vision adjustment
c. No change
d. Extremely dilated
b. Constricted for near vision adjustment
325
What do additional frequencies superimposed on the main tone produce?
A tuning fork produces a pure tone (no overtones). Most sounds are complex, with different mixes of overtones.
326
What gives different instruments or voices their unique sound?
Different mixes of overtones (e.g., C note on trumpet vs. piano).
327
What does timbre help us do?
Timbre helps us recognize where a sound comes from, since every sound source has its own pattern of overtones.
328
What is the loudness (in dB) of rustle of leaves, and how loud is it compared to the faintest audible sound?
10 dB; 10 times as loud.
329
What is the loudness (in dB) of ticking of watch, and how loud is it compared to the faintest audible sound?
20 dB; 100 times as loud.
330
What is the loudness (in dB) of hush of library, and how loud is it compared to the faintest audible sound?
30 dB; 1 thousand times as loud.
331
What is the loudness (in dB) of normal conversation, and how loud is it compared to the faintest audible sound?
60 dB; 1 million times as loud.
332
What is the loudness (in dB) of food blender, and how loud is it compared to the faintest audible sound?
90 dB; 1 billion times as loud.
333
What is the loudness (in dB) of loud rock concert, and how loud is it compared to the faintest audible sound?
120 dB; 1 trillion times as loud.
334
What is the loudness (in dB) of takeoff of jet plane, and how loud is it compared to the faintest audible sound?
150 dB; 1 quadrillion times as loud.
335
What must happen to sound waves in air?
Sound waves in air must be channeled and transferred into this fluid environment.
336
Why do the external ear and middle ear work together?
Because sound loses energy moving from air to fluid, the external ear and middle ear work together to amplify and direct sound waves toward the inner ear.
337
What does the pinna do?
The pinna collects and funnels sound waves into the ear canal.
338
Why is the shape of the pinna important in humans?
Humans can’t move the pinna like some animals, but its shape helps distinguish front vs. back sounds.
339
What does sound localization rely on?
– Timing difference: sound reaches one ear slightly earlier. – Intensity difference: sound is softer in the farther ear.
340
What does the auditory cortex do for sound localization?
The auditory cortex compares these cues to find the sound’s location.
341
Why is it hard to localize sound with only one ear?
It’s hard to localize sound with only one ear.
342
What happens when the tympanic membrane is struck by sound waves?
Vibrates when struck by sound waves → moves in and out with the same frequency.
343
What is needed for free vibration of the tympanic membrane?
Equal air pressure on both sides is needed for free vibration.
344
What does the Eustachian tube do?
Eustachian tube connects the middle ear to the throat → opens when we yawn, chew, or swallow to balance pressure.
345
What can rapid pressure changes (like during a flight) do to the eardrum?
Rapid pressure changes (like during a flight) can make the eardrum bulge until the Eustachian tube opens to equalize pressure, creating a brief “pop” as it returns to normal.
346
How can throat infections affect the ear?
Throat infections can spread through the tube → cause fluid buildup and hearing problems.
347
What does the middle ear transfer?
Transfers vibrations from the tympanic membrane (eardrum) to the inner ear fluid.
348
What are the three small bones (ossicles) of the middle ear?
– Malleus (hammer) – attached to eardrum – Incus (anvil) – middle bone – Stapes (stirrup) – attached to oval window of cochlea.
349
How do the ossicles vibrate?
These bones vibrate together with the same frequency as the sound.
350
How do the ossicles amplify pressure?
The ossicles amplify pressure in two ways: – Smaller oval window area increases pressure. – Lever action adds extra force.
351
How much does the ossicles’ action increase sound force?
Together, this increases sound force about 20×.
352
What is the protective reflex of the middle ear?
Protective reflex: Muscles tighten the ossicles in response to loud sounds (>70 dB) to protect the inner ear.
353
What type of sounds does the protective reflex work for?
Works for prolonged sounds, not sudden ones (like explosions).
354
Parasympathetic effect on digestive secretions:
a. Inhibited b. Stimulated ✅ c. No effect d. Reduced
355
Sympathetic effect on urinary bladder:
a. Contracted b. Relaxed ✅ c. Stimulated d. Emptying
356
Parasympathetic effect on urinary bladder:
a. Relaxed b. Contracted (emptying) ✅ c. No effect d. Dilated
357
Sympathetic effect on pupil:
a. Constricted b. Dilated for far vision adjustment ✅ c. Normal d. Closed
358
Parasympathetic effect on pupil:
a. Dilated b. Constricted for near vision adjustment ✅ c. No change d. Extremely dilated
359
How are internal organs controlled?
Automatically by the autonomic nervous system (ANS), not by conscious effort.
360
What type of input do most organs receive?
Both sympathetic and parasympathetic input with opposite effects.
361
What is the sympathetic effect on the heart and digestion?
Increases heart rate and reduces digestion.
362
What is the parasympathetic effect on the heart and digestion?
Slows heart rate and promotes digestion.
363
What is autonomic tone?
The partial activity of both sympathetic and parasympathetic systems at rest.
364
When does dominance occur in the ANS?
When one system’s activity increases while the other decreases.
365
What maintains homeostasis between the ANS branches?
The dynamic balance between sympathetic and parasympathetic activity.
366
When does the sympathetic system dominate?
In emergency or stressful “fight-or-flight” situations.
367
What happens to heart rate, blood pressure, and breathing during sympathetic dominance?
They all increase.
368
How does sympathetic dominance affect blood flow?
Blood is redirected to muscles, the heart, and the brain.
369
How does sympathetic activity affect digestion and urination?
Both are inhibited to conserve energy.
370
How does the sympathetic system affect energy stores?
It mobilizes glucose and fat for immediate use.
371
What happens to sweating, vision, and hearing during sympathetic dominance?
They all increase to improve alertness.
372
When does the parasympathetic system dominate?
In quiet, relaxed, “rest-and-digest” situations.
373
What is the main function of the parasympathetic system during dominance?
It promotes body-maintenance activities, such as digestion.
374
What is the advantage of dual autonomic innervation?
It allows precise regulation of organ activity through coordinated sympathetic and parasympathetic control.
375
How does dual innervation help with organ adjustments?
Antagonistic control enables faster, smoother changes (e.g., heart rate decreases faster when parasympathetic activity increases while sympathetic decreases).
376
What is the exception for blood vessels in terms of innervation?
They are mostly controlled by sympathetic fibres only (tonic control). Parasympathetic innervation occurs only in the penis and clitoris for erection.
377
What is unusual about sweat gland innervation?
They are sympathetic only, but their sympathetic fibres release acetylcholine (ACh), which is unusual.
378
How are salivary glands innervated differently?
They receive both sympathetic and parasympathetic input, but it is not antagonistic—both increase secretion, just with different composition and volume.
379
What is the adrenal medulla?
It is a modified part of the sympathetic nervous system and does not have postganglionic fibres.
380
Where is the adrenal medulla located?
It is the inner layer of each adrenal gland, which sits above each kidney.
381
What does the outer layer of the adrenal gland do?
The adrenal cortex secretes steroid hormones.
382
What stimulates the adrenal medulla to release hormones?
Stimulation of preganglionic sympathetic fibres.
383
What hormones does the adrenal medulla release and in what proportions?
80% epinephrine (adrenaline) 20% norepinephrine (noradrenaline)
384
What is the function of epinephrine and norepinephrine released from the adrenal medulla?
They reinforce and prolong sympathetic effects, such as increased heart rate, blood pressure, and energy release.
385
What determines the effect of a neurotransmitter in the autonomic nervous system?
The receptor type it binds to, not the chemical itself.
386
Can the same neurotransmitter cause both stimulation and inhibition?
Yes — depending on the receptor subtype present on the target tissue.
387
What happens when a neurotransmitter binds to its receptor on a target tissue?
It triggers a specific tissue response.
388
Why do different tissues respond differently to the same neurotransmitter?
Because target tissues have different receptor proteins on their membranes.
389
What types of receptors do autonomic target tissues have?
They have one or more receptor types for postganglionic neurotransmitters.
390
What do cholinergic receptors bind to?
Acetylcholine (ACh).
391
Where are nicotinic receptors found?
On postganglionic cell bodies of all autonomic ganglia.
392
Where are muscarinic receptors found?
On effector cell membranes (smooth muscle, cardiac muscle, and glands).
393
Where are nicotinic receptors located functionally (between what structures)?
At the ganglia (between neurons), where they transmit signals quickly.
394
Where are muscarinic receptors located functionally (between what structures)?
At the target organs (between neuron and effector—control organ responses).
395
How do nicotinic and muscarinic receptors work together?
They ensure smooth and balanced autonomic function.
396
Where are nicotinic receptors found?
On postganglionic cell bodies in all autonomic ganglia (sympathetic & parasympathetic) and on skeletal muscle at the neuromuscular junction.
397
What activates nicotinic receptors?
Acetylcholine (ACh).
398
What is the main function of nicotinic receptors?
Allows fast transmission from preganglionic → postganglionic neuron (or to skeletal muscle).
399
Which autonomic systems use nicotinic receptors?
Sympathetic and parasympathetic.
400
Where are muscarinic receptors found?
On effector cell membranes of smooth muscle, cardiac muscle, and glands (parasympathetic targets).
401
What activates muscarinic receptors?
Acetylcholine (ACh).
402
What is the main function of muscarinic receptors?
Causes parasympathetic responses (↓ heart rate, ↑ digestion, ↑ gland secretion).
403
Which autonomic system uses muscarinic receptors?
Parasympathetic only.
404
Where are Nicotinic found?
in ganglia (fast)
405
Where are Muscarinic found?
At organs (slow, parasympathetic effects)
406
What neurotransmitters bind to adrenergic receptors?
Norepinephrine and epinephrine.
407
What are the α-adrenergic receptor types?
α₁ and α₂.
408
What are the β-adrenergic receptor types?
β₁, β₂, and β₃.
409
Where are α₁ receptors mainly located?
Blood vessels.
410
What is the effect of α₁ receptor activation?
Vasoconstriction → increased blood pressure.
411
Give an example of tissue with α₁ receptors.
Arteriolar smooth muscle.
412
Where are α₂ receptors mainly found?
Digestive tract.
413
What is the effect of α₂ receptor activation?
Inhibition of digestive tract motility.
414
Give an example of tissue with α₂ receptors.
Digestive smooth muscle.
415
Where are β₁ receptors mainly located?
The heart.
416
What is the effect of β₁ receptor activation?
Increased heart rate and increased force of contraction.
417
Give an example of tissue with β₁ receptors.
Cardiac muscle.
418
Where are β₂ receptors mainly found?
Lungs and arterioles.
419
What is the effect of β₂ receptor activation?
Relaxation (dilation).
420
Give an example of tissue with β₂ receptors.
Airway smooth muscle (airway dilation).
421
Where are β₃ receptors mainly located?
Fat (adipose) tissue.
422
What is the effect of β₃ receptor activation?
Fat breakdown (lipolysis).
423
What do all adrenergic receptors do?
all act through G-proteins and second messengers to control cell activity
424
What do autonomic agonists do?
They bind to receptors and mimic neurotransmitters.
425
What do autonomic antagonists do?
They bind to receptors and block neurotransmitters.
426
What type of drug is Atropine—agonist or antagonist?
Parasympathetic antagonist (muscarinic blocker).
427
Which receptors does atropine block?
Muscarinic receptors on smooth muscle, cardiac muscle, and glands.
428
Does atropine affect nicotinic receptors?
No, it has no effect on nicotinic receptors (so sympathetic activity stays normal).
429
Why is atropine given before surgery? (Two reasons)
↓ Salivary and bronchial secretions → prevents fluid inhalation. ↑ Heart rate → by blocking vagal (parasympathetic) slowing.
430
How does atropine increase heart rate?
It blocks parasympathetic input that normally slows the heart.
431
What happens to sympathetic activity when atropine is given?
It remains unchanged, because atropine only blocks muscarinic (parasympathetic) receptors.
432
What type of drug is Salbutamol (Ventolin)?
A sympathetic agonist (β₂-adrenergic activator).
433
What conditions is Salbutamol used to treat?
Asthma and bronchospasm.
434
How does Salbutamol provide fast relief?
By relaxing smooth muscle in the airways.
435
Which receptor type does Salbutamol selectively activate?
β₂-adrenergic receptors.
436
What is the effect of activating β₂ receptors in the bronchioles?
Bronchodilation (airway relaxation), which improves airflow.
437
Why does Salbutamol not significantly affect the heart?
Because it mainly targets β₂ receptors, while the heart has mostly β₁ receptors.
438
What is the main location of β₂ receptors?
Lungs and arterioles.
439
What is the effect of β₂ receptor activation?
Relaxation/dilation of smooth muscle (airway dilation).
440
What is the main autonomic function controlled by the spinal cord?
Controls basic autonomic reflexes (e.g., urination, defecation, erection—can be overridden by higher brain centers).
441
What is the main autonomic role of the medulla (brain stem)?
It is the main control center for autonomic output, regulating heart rate, breathing, and digestion.
442
What does the hypothalamus integrate?
Integrates autonomic, somatic, and endocrine responses, especially during emotions (e.g., anger and fear increase HR, BP, breathing).
443
How does the prefrontal cortex contribute to autonomic control?
Influences emotional expression through the hypothalamus and medulla (e.g., blushing when embarrassed, facial reactions tied to personality).
444
What does the somatic nervous system consist of?
Axons of motor neurons that originate in the spinal cord or brain stem and end on skeletal muscle.
445
What neurotransmitter do somatic motor neurons release?
Acetylcholine (ACh).
446
What does ACh released by motor neurons do?
Stimulates skeletal muscle contraction.
447
What are motor neurons considered in the control pathway?
The final common pathway through which the CNS controls skeletal muscle activity.
448
Which CNS areas exert control over somatic (skeletal muscle) activity?
The spinal cord, motor regions of the cortex, basal nuclei, cerebellum, and brain stem.
449
What types of inputs do motor neurons receive?
They receive both excitatory and inhibitory inputs.
450
What are the two major sources of input to motor neurons?
Spinal reflex pathways (from sensory receptors) and descending pathways from the motor cortex, basal nuclei, cerebellum, and brain stem.
451
What determines the activity of a motor neuron?
The balance between EPSPs (excitatory postsynaptic potentials) and IPSPs (inhibitory postsynaptic potentials) from its inputs.
452
Why are motor neurons called the “final common pathway”?
Because all inputs—reflexive and voluntary—must converge on the motor neuron, which ultimately sends the signal to the muscle.
453
Is the somatic motor system fully voluntary?
No. Although voluntary, many movements (posture, balance, walking rhythm) are subconsciously controlled by lower brain centers.
454
What type of control does the somatic nervous system have?
Voluntary (conscious)
455
What type of control does the autonomic nervous system have?
Involuntary (automatic)
456
What are the effector organs of the somatic nervous system?
Skeletal muscles
457
What are the effector organs of the autonomic nervous system?
Smooth muscle, cardiac muscle, and glands
458
Describe the neural pathway of the somatic nervous system.
One-neuron pathway; the motor neuron extends directly from the CNS to the muscle
459
Describe the neural pathway of the autonomic nervous system.
Two-neuron chain: preganglionic neuron + postganglionic neuron
460
What neurotransmitter does the somatic nervous system use?
Acetylcholine (ACh)
461
What neurotransmitters does the autonomic nervous system use?
ACh (parasympathetic) and Norepinephrine (sympathetic)
462
What is the effect of somatic nervous system output on the effector?
Always stimulatory (causes contraction)
463
What is the effect of autonomic nervous system output on effectors?
Can be stimulatory or inhibitory, depending on receptor type
464
Where are the cell bodies located in the somatic nervous system?
Ventral horn of the spinal cord (or brainstem for head muscles)
465
Where are the cell bodies located in the autonomic nervous system?
Autonomic ganglia (outside the CNS)
466
Give an example function of the somatic nervous system.
Moving the arm, walking, facial expression
467
Give an example function of the autonomic nervous system.
Regulating heart rate, digestion, pupil size
468
(STUDY GUIDE): What is hearing?
Perception of sound energy through mechanical vibration of air molecules.
469
(STUDY GUIDE): Sound waves alternate between what two phases?
Compressions (high pressure)
and rarefactions (low pressure).
470
What determines pitch? TSUDY
Frequency (Hz).
👉 Human hearing range: 20–20,000 Hz
👉 Most sensitive range: 1,000–4,000 Hz
471
What determines loudness? STUDY
Amplitude,
measured in decibels (dB).
+10 dB = 10× increase in loudness
100 dB = risk of cochlear damage
472
(STUDY GUIDE): What determines sound quality (timbre)?
Overtones that give each sound a unique character. (ex. same note on piano vs violin)
473
(STUDY GUIDE): What is the function of the pinna?
Collects and funnels sound into the ear canal; helps localize sound (front vs. back).
474
(STUDY GUIDE): What lines the auditory canal and what is its purpose?
Hair and ceruminous glands (earwax) → trap dust and protect the eardrum.
475
(STUDY GUIDE): What is the function of the tympanic membrane?
Vibrates with incoming sound waves.
Also equalizes air pressure via the Eustachian tube to prevent bulging during altitude changes.
476
(STUDY GUIDE): What are the auditory ossicles?
Malleus (hammer)
Incus (anvil)
Stapes (stirrup)
477
(STUDY GUIDE): How does the middle ear amplify vibrations?
By lever action and smaller oval-window surface area → ~20× amplification.
478
(STUDY GUIDE): What is the protective reflex of the middle ear?
Ossicle muscles tighten during loud prolonged sounds (>70 dB) to reduce vibration transmission.
479
(STUDY GUIDE): What are the two main parts of the inner ear and their functions?
Cochlea → hearing organ
Vestibular apparatus → balance & equilibrium
480
(STUDY GUIDE): What are the three fluid-filled chambers of the cochlea?
Scala vestibuli (top, perilymph)
Cochlear duct / Scala media (middle, endolymph)
Scala tympani (bottom, perilymph)
481
(STUDY GUIDE): List the pathway of sound vibration through the ear.
1️⃣ Sound → ear canal → eardrum vibrates
2️⃣ Ossicles transmit vibration → oval window (stapes)
3️⃣ Pressure waves travel through cochlear fluids
4️⃣ Basilar membrane moves → bends hair cells (Organ of Corti)
5️⃣ Ion channels open → depolarization → auditory nerve APs
482
(STUDY GUIDE): What is the role of inner hair cells (IHCs)?
Main sound receptors → send signals via the auditory nerve.
483
(STUDY GUIDE): What is the role of outer hair cells (OHCs)?
Amplify and fine-tune vibrations by changing length (electromotility).
484
(STUDY GUIDE):
Where are high and low pitches detected on the basilar membrane?
Base → high pitch (high frequency)
Apex → low pitch (low frequency)
485
(STUDY GUIDE): How is loudness coded in the cochlea?
Greater amplitude → greater basilar membrane vibration → more nerve firing → louder sound.
486
(STUDY GUIDE): What is the auditory neural pathway?
Hair cells → Auditory nerve → Brainstem → Thalamus (MGN) → Primary Auditory Cortex (temporal lobe)
487
(STUDY GUIDE): What causes conductive deafness?
Sound transmission failure in external or middle ear
(e.g., earwax, infection, ossicle stiffness)
488
(STUDY GUIDE): What causes sensorineural deafness?
Inner-ear or nerve damage
(e.g., Organ of Corti or auditory nerve damage)
489
(STUDY GUIDE): What is a treatment option for conductive hearing loss?
Hearing aids amplify sound.
490
(STUDY GUIDE): What do cochlear implants do?
Directly stimulate the auditory nerve
491
(STUDY GUIDE): What does emerging research focus on for hearing loss?
Hair-cell regeneration + neural growth factors to restore hearing.
492
(STUDY GUIDE): Where is the vestibular apparatus located and what does it do?
Inner ear — provides information about head position, motion, and balance.
493
(STUDY GUIDE): What do semicircular canals detect?
Rotational (angular/accelerative) movements in 3 planes.
494
(STUDY GUIDE): What structures detect linear movement and head tilt?
Utricle (horizontal movement)
Saccule (vertical movement)
495
(STUDY GUIDE): What are otolith organs and what do they contain?
Utricle + saccule → contain otolith crystals in a gelatinous matrix.
496
(STUDY GUIDE): Describe the vestibular pathway.
Hair-cell signals → vestibulocochlear nerve (CN VIII) → brainstem & cerebellum → balance, posture, eye coordination.
497
(STUDY GUIDE): Where are taste receptors located?
In ~10,000 taste buds on tongue papillae
(circumvallate, fungiform, foliate)
498
(STUDY GUIDE): What cells make up a taste bud and lifespan?
~50 receptor + supporting + basal cells
Lifespan ≈ 10 days
499
(STUDY GUIDE): What is the primary site for taste molecule binding?
Taste pore → dissolved tastants contact microvilli.
500
(STUDY GUIDE): List the five primary tastes and signaling basics.
Salty: Na⁺ entry → depolarization
Sour: H⁺ blocks K⁺ channels → depolarization
Sweet: G-protein → close K⁺ channels → depolarization
Bitter: G-protein (gustducin) → PLC → Ca²⁺ release (defense)
Umami: Glutamate → G-protein → depolarization
501
(STUDY GUIDE):
What cranial nerves carry taste information?
CN VII (Facial)
IX (Glossopharyngeal),
X (Vagus)
502
(STUDY GUIDE): What is the neural pathway for taste?
CN VII/IX/X → Brainstem → Thalamus → Gustatory Cortex (parietal lobe & insula)
503
(STUDY GUIDE): What influences flavor perception?
Taste + smell + temperature + texture + emotion interaction.
504
(STUDY GUIDE): Where is the olfactory mucosa located & how big is it?
Roof of nasal cavity, ~3 cm² area.
505
(STUDY GUIDE):
What are the 3 cell types in the olfactory mucosa?
1️⃣ Olfactory receptor cells (afferent neurons with cilia)
2️⃣ Supporting cells (secrete mucus)
3️⃣ Basal cells (form new receptors every ~2 months)
506
(STUDY GUIDE): What are two requirements for odorants?
Must be volatile (vaporized) & water-soluble (dissolve in mucus)
507
(STUDY GUIDE): Summarize the olfactory pathway.
Olfactory nerve → Olfactory bulb → Glomeruli → Mitral cells →
1️⃣ Limbic system (emotion, behavior)
2️⃣ Olfactory cortex (conscious smell perception)
508
(STUDY GUIDE): How does olfactory transduction occur?
Odorant binds receptor → G-protein activation → Na⁺ channels open → depolarization.
509
(STUDY GUIDE): How many odors can humans distinguish and how?
> 10,000 based on unique glomerular activation patterns.
510
(STUDY GUIDE): What causes smell adaptation?
Reduced sensitivity with continued exposure; enzymes in mucus detoxify odorants.
511
(STUDY GUIDE): What is the vomeronasal organ and what is its function in humans?
Detects pheromones in animals; function uncertain in humans.
512
(STUDY GUIDE): What branch of the nervous system is the ANS and what does it control?
Involuntary branch of PNS; controls cardiac muscle, smooth muscle, and glands.
513
(STUDY GUIDE): What does the ANS maintain?
Homeostasis & coordinate stress responses (fight-or-flight).
514
(STUDY GUIDE): What are the two divisions of the ANS and their roles?
Sympathetic → fight-or-flight (activates body)
Parasympathetic → rest-and-digest (restores energy)
515
(STUDY GUIDE):
What are the origins of the sympathetic vs parasympathetic systems?
Sympathetic: Thoracolumbar
Parasympathetic: Craniosacral
516
(STUDY GUIDE): What are the two neurons in the ANS pathway?
1️⃣ Preganglionic neuron (cell body in CNS → synapses in ganglion)
2️⃣ Postganglionic neuron (innervates effector organ)
517
(STUDY GUIDE): What neurotransmitter is released by all preganglionic neurons?
ACh (cholinergic)
518
(STUDY GUIDE): What neurotransmitter do sympathetic postganglionic neurons release?
NE (adrenergic)
519
(STUDY GUIDE): What is dual innervation?
Most organs receive both sympathetic & parasympathetic input (opposite effects).
520
(STUDY GUIDE): What does the adrenal medulla release and in what proportions?
~80% epinephrine + 20% norepinephrine → prolongs sympathetic effects.
521
(STUDY GUIDE): Where are nicotinic receptors located & what activates them?
Postganglionic cell bodies (both divisions) & skeletal muscle; activated by ACh
522
(STUDY GUIDE): What is the main effect of nicotinic receptors?
Fast transmission from CNS → ganglion or muscle
523
(STUDY GUIDE): Which system uses nicotinic receptors?
Sympathetic & Parasympathetic
524
(STUDY GUIDE): Where are muscarinic receptors found & what activates them?
Effector organs (smooth & cardiac muscle, glands); activated by ACh
525
STUDY GUIDE): What is the main effect of muscarinic receptors & which system are they in?
Parasympathetic effects (↓ HR, ↑ digestion) → Parasympathetic only
526
(STUDY GUIDE): α1 receptor — location, activation, effect, system?
Blood vessels; activated by NE/Epi → Vasoconstriction ↑ BP; Sympathetic
527
(STUDY GUIDE): α2 receptor — location, activation, effect, system?
Digestive tract; activated by NE → ↓ motility; Sympathetic
528
(STUDY GUIDE): β1 receptor — location, activation, effect, system?
Heart; activated by NE/Epi → ↑ HR & force; Sympathetic
529
(STUDY GUIDE): β2 receptor — location, activation, effect, system?
Lungs & arterioles; activated by Epi → Bronchodilation; Sympathetic
530
Lungs & arterioles; activated by Epi → Bronchodilation; Sympathetic
Adipose tissue; activated by NE → Lipolysis; Sympathetic
531
(STUDY GUIDE): What does Atropine do?
Muscarinic blocker → ↓ secretions & ↑ HR
532
(STUDY GUIDE): What does Salbutamol (Ventolin) do?
β2 agonist → relaxes bronchioles (asthma relief)
533
(STUDY GUIDE): What type of control is the somatic nervous system?
Voluntary control of skeletal muscles
534
(STUDY GUIDE): How many neurons are in the somatic pathway?
One motor neuron from CNS → muscle
535
(STUDY GUIDE): What neurotransmitter does the somatic NS use?
ACh
536
(STUDY GUIDE): SNS stimulation effect type?
Always stimulatory
537
(STUDY GUIDE): Which system has stimulatory OR inhibitory effects?
Autonomic
538
(STUDY GUIDE): What does Poliovirus destroy & what does it cause?
Destroys motor neurons → paralysis
539
(STUDY GUIDE): What happens in ALS?
Progressive degeneration of motor neurons → muscle weakness & atrophy
540
(STUDY GUIDE): Where are nicotinic receptors located?
Postganglionic cell bodies (both divisions) & skeletal muscle.
541
(STUDY GUIDE): What activates nicotinic receptors, and what is their effect?
ACh → fast transmission in CNS, ganglion, or muscle.
542
(STUDY GUIDE): Which ANS divisions use nicotinic receptors?
Sympathetic & Parasympathetic
543
(STUDY GUIDE): What is the main effect of muscarinic receptors?
A: Parasympathetic effects
↓ HR, ↑ digestion
544
(STUDY GUIDE): Where are muscarinic receptors located and what activates them?
Effector organs (smooth/cardiac muscle, glands) → ACh
545
(STUDY GUIDE): α₁ receptor location & effect?
Blood vessels → Vasoconstriction → ↑ BP
546
(STUDY GUIDE): α₂ receptor location & effect?
Digestive tract → ↓ motility
547
(STUDY GUIDE): β₁ receptor location & effect?
Heart → ↑ heart rate & contractility
548
(STUDY GUIDE): β₂ receptor location & effect?
Lungs/arterioles → Bronchodilation
549
(STUDY GUIDE): β₃ receptor location & effect?
Adipose tissue → Lipolysis (fat breakdown)
550
(STUDY GUIDE): How does Atropine affect autonomic signaling?
Muscarinic blocker → ↓ secretions, ↑ HR
551
(STUDY GUIDE): What does Salbutamol (Ventolin) target?
β₂ agonist → bronchodilation (asthma relief)
552
(STUDY GUIDE): What does the somatic nervous system control?
Voluntary control of skeletal muscle
553
(STUDY GUIDE): How many neurons connect CNS to muscle in the somatic system?
One motor neuron (releases ACh → always stimulatory)
554
(STUDY GUIDE): Somatic vs Autonomic — Control type?
Somatic = voluntary
Autonomic = involuntary
555
(STUDY GUIDE): What brain & spinal areas help regulate movement subconsciously?
Spinal cord, motor cortex, basal nuclei, cerebellum, brainstem
556
(STUDY GUIDE): Neurotransmitters — Somatic vs Autonomic?
Somatic = ACh only
Autonomic = ACh or NE
557
(STUDY GUIDE): Effector type — Somatic vs Autonomic?
Somatic = Skeletal muscle
Autonomic = Smooth & cardiac muscle, glands
558
(STUDY GUIDE): What does poliovirus damage & what results?
Destroys motor neurons → paralysis
559
(STUDY GUIDE): Pathway comparison — Somatic vs Autonomic
Somatic = one neuron
Autonomic = two neurons (pre- & postganglionic)
560
(STUDY GUIDE): What is ALS and what does it cause?
Progressive motor neuron degeneration → muscle weakness & atrophy
561
(STUDY GUIDE): What neurotransmitter activates nicotinic receptors?
ACh
562
(STUDY GUIDE): Where are nicotinic receptors located?
Postganglionic cell bodies of both ANS divisions & skeletal muscle
563
(STUDY GUIDE): What is the main effect of nicotinic receptor activation?
Fast synaptic transmission to ganglion or muscle
564
(STUDY GUIDE): Which system(s) use nicotinic receptors?
Sympathetic & Parasympathetic
565
(STUDY GUIDE): Muscarinic receptors are found on what types of effector organs?
Smooth muscle, cardiac muscle, glands
566
(STUDY GUIDE): What activates muscarinic receptors?
ACh
567
(STUDY GUIDE): Which division uses muscarinic receptors?
Parasympathetic only
568
(STUDY GUIDE): What are the main effects of muscarinic receptor activation?
Parasympathetic effects: ↓ heart rate, ↑ digestion
569
(STUDY GUIDE): α₁ receptors are located where?
Blood vessels
570
(STUDY GUIDE): What activates α₁ receptors?
NE/Epi
571
(STUDY GUIDE): What is the effect of α₁ receptor activation?
Vasoconstriction → ↑ blood pressure
572
(STUDY GUIDE): α₁ receptors belong to which system?
Sympathetic
573
(STUDY GUIDE): Where are α₂ receptors located?
Digestive tract
574
(STUDY GUIDE): α₂ receptor activation effect?
↓ motility
575
(STUDY GUIDE): α₂ system?
Sympathetic
576
(STUDY GUIDE): β₁ receptor location?
Heart
577
(STUDY GUIDE): β₁ receptor location?
NE/Epi
578
(STUDY GUIDE): Effect of β₁ receptor activation?
↑ heart rate & ↑ force of contraction
579
(STUDY GUIDE): β₁ receptors belong to which system?
Sympathetic
580
(STUDY GUIDE): β₂ receptor location?
Lungs & arterioles
581
(STUDY GUIDE): What activates β₂ receptors?
Epi (only)
582
(STUDY GUIDE): Effect of β₂ receptor activation?
Bronchodilation / vasodilation
582
(STUDY GUIDE): β₂ system?
Sympathetic
583
(STUDY GUIDE): β₃ receptor location?
Adipose tissue
584
(STUDY GUIDE): What activates β₃ receptors?
NE
585
(STUDY GUIDE): Main effect of β₃ receptor activation?
Lipolysis (fat breakdown)
586
(STUDY GUIDE): β₃ receptors belong to which system?
Sympathetic
587
(STUDY GUIDE): Somatic control type?
Voluntary
588
(STUDY GUIDE): Somatic effector type?
Skeletal muscle
589
(STUDY GUIDE): Somatic neural pathway?
One motor neuron from CNS to muscle
590
(STUDY GUIDE): Somatic neurotransmitter?
ACh
591
(STUDY GUIDE): Somatic effect on target?
Always stimulatory
592
(STUDY GUIDE): Somatic example?
Walking or smiling
593
(STUDY GUIDE): Autonomic control type?
Involuntary
594
(STUDY GUIDE): Autonomic effectors?
Smooth muscle, cardiac muscle, glands
595
(STUDY GUIDE): Autonomic neural pathway?
Two neurons: preganglionic + postganglionic
596
(STUDY GUIDE): Autonomic effects on target?
Stimulatory or inhibitory
597
(STUDY GUIDE): Autonomic neurotransmitters?
ACh or NE
598
(STUDY GUIDE): Autonomic example?
Regulating HR or digestion
599
STUDY - Parietal lobes
touch and taste
600
STUDY - Occipital lobe
vision
601
STUDY - temporal lobe
hearing and smell
602
STUDY - Insula
taste and balance
