Sensory System Flashcards
1
Q
What are sensory receptors?
A
specialized neurons or other cells that are tuned to the conditions of the external world or internal organs; provide sensation
2
Q
What is a “sensation?”
A
awareness
3
Q
True or False: Sensation differs form perception
A
True
4
Q
What is “perception?”
A
interpretation
5
Q
All sensory receptors:
A
- trigger an action potential
- send information to the central nervous system
6
Q
What is the order sensation occurs?
A
transduction, conduction, translation, and perception
7
Q
What is transduction?
A
sensory receptor responds to stimulus and converts
it to a nerve impulse
* it produces a change in the cell’s membrane potential
8
Q
What is conduction?
A
Electrical signals are transmitted along sensory neurons to CNS/ from receptor in the sense organ to CNS (cerebral
cortex)
9
Q
What is translation?
A
brain interprets signals converting them to meaningful perceptions/DNA translates impulse into sensation
10
Q
What is perception?
A
conscious experience of sensory information, allowing us to recognize and respond to stimuli
11
Q
What is receptor potential?
A
Changes in the flow of ions create a graded change in membrane
potential in sensory receptor cells
* Receptor potentials vary; the stronger the stimulus, the greater the
receptor potential.
* more neurotransmitters released by the receptor cell
* more frequently the sensory neuron transmits action potentials to the brain
12
Q
What are the four main lobes of the brain?
A
Frontal, Parietal, Temporal, Occipital
13
Q
What is the frontal lobe responsible for?
A
Frontal association area: speech and motor cortex
14
Q
What is the Parietal Lobe responsible for?
A
Somatosensory association area: somatosensory cortex, taste, speech, and reading
15
Q
What is the Temporal Lobe responsible for?
A
Auditory association area: Smell, hearing
16
Q
What is the Occipital Lobe responsible for?
A
Visual Association area: vison
17
Q
What is a receptive field?
A
- the stimulus region
- has features that cause the maximal
response of a cell in a sensory
system.
18
Q
How is receptive field measured?
A
2 point discrimination test
19
Q
What is the 2 point discrimination test?
A
ability to discern that two nearby
objects touching the skin are truly two distinct points, not one
20
Q
What are the five specialized sensory receptors?
A
Pain receptors, thermoreceptors, mechanoreceptors, chemoreceptors, and electromagnetic receptors
21
Q
What are pain receptors?
A
detect dangerous stimuli
including high heat and pressure
22
Q
What are thermoreceptors?
A
Responds to temperature
variations; detect heat or cold
23
Q
What are mechanoreceptors?
A
- Sensitive to physical
environment; generates action
potentials in response - mechanical energy, touch,
pressure, and sound
24
Q
What are chemoreceptors?
A
- Responsible for sensing specific
substances in the environment;
respond to chemicals - sensory receptors in our nose
and taste buds
25
What are electromagnetic receptors?
respond to:
* electricity
* magnetism
* light (sensed by
photoreceptors)
26
What is the sensory nervous system?
Interaction of sensory receptors and your nervous system response to those
stimuli
27
What are the general (somatic) senses?
* Temperature
* Touch
* Pain
* Pressure
* Body position
28
What are the special senses?
– Smell
– Taste
– Hearing
– Vision
– Equilibrium
29
Where does touch originate?
The bottom layer of the skin-the dermis
30
What is sensory adaptation?
a reduction in sensitivity to a stimulus after constant
exposure to it
31
What receptor does taste and smell depend on?
chemoreceptors that detect specific
chemicals in the environment
* in taste buds detect molecules in solution
* those lining the nasal cavity detect airborne molecules
32
Which is the weakest of the five special senses in humans?
taste
33
What are taste receptors?
* located in taste buds on the tongue
* produce five taste sensations:
* sweet
* salty
* sour
34
Is spicy a taste?
No! It is the sensation of temperature in the tongue
resulting from the destruction of taste buds by the
‘hot’ food like chili
35
What is the pathway of taste?
Cranial Nerves VII , IX and CN X
carry impulses from taste buds
brain.
* Medulla
* Thalamus
* Cerebrum (gustatory cortex)
* Hypothalamus and limbic system
36
What is a super taster?
those who believe that foods may have much stronger flavors, which often leads to supertasters having very strong likes and
dislikes for different foods
37
True of False: Taste changes as you age?
True!
* When you were a baby, you had taste buds, not only on your tongue, but on the
sides and roof of your mouth
* As you grew, the taste buds began to disappear from the sides and roof of your
mouth, leaving taste buds mostly on your tongue.
* As you get older, your taste buds will become even less sensitive, so you will
be more likely to eat foods that you thought were too strong as a child.
38
True or False: Smell owns taste
True
39
What is the difference between general and special senses?
General sense are widespread, whereas special sense are localized
40
Why do pain receptors not readily adapt like most sensory receptors?
They serve to alert the body of potential harm, ensuring that damaging stimuli are continuously monitored.
41
Why might being a supertaster be considered harmful to your health?
Supertasters have a heightened sensitivity to certain tastes, specifically bitter flavors. This could lead to aversions to healthy foods, such as vegetables, leading to a less balanced diet and even potential health deficiencies.
42
What is the olfactory pathway molecules take after entering the nasal cavity?
Odor molecules bind to olfactory receptors in the olfactory epithelium, initiating a signal to travel through the olfactory bulb, and then to the olfactory cortex in the brain where the scent is processed and identified.
43
What is the sense of smell dependent on?
olfactory cells located within
olfactory epithelium high in the roof
of the nasal cavity
44
What is the limbic system?
two partial rings around them
formed by portions of the
cerebral cortex.
Hippocampus, amygdala,
thalamus & hypothalamus
45
What causes sensations like gustation and olfaction to change with age?
Degeneration of sensory receptors and decreased sensitivity of the olfactory and taste cells
46
What is the order of the ear as encountered by soundwaves?
Auditory canal, tympanic membrane, ear drum, auditory ossicles, and cochlea
47
What is the tympanic membrane?
*Tightly stretched membrane across
entrance to middle ear
* vibrates when struck by sound waves
* Vibrates from waves and causes air on
other side of eardrum to vibrate.
48
What can lead to ear damage?
* Wax pushed up from q-tip use
* Sharp objects that puncture tympanic membrane
* Born with damaged ear canal or without pinna
* Swimmer’s Ear
49
What middle ear damage can lead to hearing loss?
* Calcium deposits on bones
* Loud sudden noises- firecracker, gunshot
* Trauma to the head- fall, car accident
* Torn muscles of the ossicles
* Otitis media
50
What makes up the inner ear?
* Cochlea (fluid & cilia)
* Semi-circular canals
* Auditory nerve (8 th cranial nerve)
51
What is the function of the ear?
converts air pressure waves to action potentials that are
perceived as sound
* Pressure waves transmitted to the fluid of the cochlea
* bend cilia in the organ of Corti against the basilar membrane
* trigger nerve signals to the brain.
* Louder sounds generate higher amplitude of pressure waves = more
action potentials.
* Various pitches stimulate different regions of the organ of Corti.
(different thickness/structure of membrane)
52
What does frequency measure?
the cycle rate of the physical waveform
53
What does pitch measure?
how
high or low it sounds when you hear it
54
What is deafness?
The loss of hearing
55
What causes deafness?
the inability to detect sounds resulting
from:
* disease, trauma
* middle-ear infections, a ruptured eardrum, or stiffening of the middle-ear bones
* genetics
damage to sensory receptors or neurons
* often progressive and permanent
56
What are the three planes fluid moves?
horizontal, posterior, superior
57
What are photoreceptors?
cells that contain pigment
molecules that absorb light
58
What is one of the simplest light-detecting organs?
invertebrate eyecup
59
What are the two major types of eye evolution?
Compound eyes and single-lens eyes
60
What are compound eyes?
* found in insects and
crustaceans
* consist of up to several thousand
light detectors called ommatidia
* function as acute motion detectors
* usually provide excellent color
vision
61
Where does light enter?
The pupil
62
What control the pupil?
The iris
63
Where does light travel after is passes through the pupil?
The single lens and is focused onto the retina
64
What does the retina consist of?
many photoreceptor cells
65
What is the center of focus?
Fovea, where photoreceptor cells are highly concentrated
66
What is the importance of herbivore eye location?
* Need to be aware of their surroundings are all
time so their eyes are mounted on the side of
their head
* wider field of view
* monocular vision
67
What is the importance of carnivore eye location?
* Need depth perception for better hunting; front
mounted eyes
* increased accuracy
* binocular vision
68
What protects the eye?
The conjunctiva and lacrimal
69
What is the conjunctie
* lines the inner surface of the eyelids
and folds back over the white of the
eye (but not the cornea)
70
What is conjunctivitis?
an inflammation of the
conjunctiva by bacteria or a virus
71
What is lacrimal?
a gland above the eye secretes tears
that clean and moisten the eye
72
What makes up the outer layer of the eye?
Sclera, and Cornea
73
What is Sclera?
outer surface of the human
eyeball is a tough, whitish layer of
connective tissue
74
What is cornea?
front of the eye, the sclera
becomes the transparent
* lets light into the eye
* helps focus light
75
What is astigmatism?
irregular shape
76
What makes up the middle layer of the eye?
Choroid
77
What is the choroid?
the sclera surrounds this
pigmented layer
* Blood vessels for eye
* Ciliary Muscle
* Iris
78
What is the Ciliary Muscle?
* extends from anterior portion of choroid – holds
lens in place
* Contract/relax of muscle - change pupil size
79
What is the Iris?
* Thin ring of pigmented muscle in front of lens
* Regulates amount of light entering eye
80
Why is the eye squishy?
The lens and ciliary body divide the eye into two
fluid-filled chambers.
* vitreous humor
* aqueous humor
81
What is the vitreous humor?
large, behind lens; jelly-like
82
What is the aqueous humor?
small, in front of lens; water
83
What are lens?
focuses light onto the retina by bending light rays
* solid but pliable, convex-shaped and transparent
* Changes in its clarity result in cataracts
84
What makes up the inner layer of the eye?
Retina
85
What are the two types of photoreceptors on retina?
Rods and Cones
86
What are rods?
* contain the visual pigment rhodopsin
* which can absorb dim light
* can detect shades of gray in dim light
* more numerous than cones
87
What are cones?
* contain the visual pigment photopsin
* which absorbs bright colored light
* allow us to see color in bright light
88
What are nocturnal eyes?
* Use rods more than cones to see at night
* Activated in low light and at night
89
What are diurnal eyes?
* Use cones more than rods
* Activated in bright light
* Allows them to see in color
90
What is trichromatic?
full color spectrum
91
What is dichromatic?
Red, green, and yellow appear similarly
92
What is the correct order of the eye in which they are encountered by photons of light traveling into the eye?
cornea, aqueous humor, pupil, lens, vitreous humor, retina
93
Why is vision mostly perceived in shades of gray rather than color?
The rods in the retina are more sensitive to light, but don't detect color, resulting in grayscale perception
94
Why does your eye have a blind spot?
The optic nerve exists the eye at the retina creating a region without photoreceptors, so no light can be detected
