ch 16 Flashcards
1
Q
What are sensory receptors?
A
- they provide information about external and internal environments
- respond to a stimulus
- Each type of receptor responds best to a type of stimulus
2
Q
Each type of receptor responds best to a type of ? Example?
A
Stimulus
Ex: light energy for eye receptors; sound energy for ear receptors
3
Q
What is sensation?
A
- A stimulus we are consciously aware of
- a lot of sensory input goes to other areas of the brain
4
Q
To enter consciousness, signals must reach the _______ ________
A
cerebral cortex
5
Q
What is the number of stimuli that results in sensation?
A
Only a fraction
6
Q
Sensation can be categorized into two portions. What are the two portions?
A
General & specialized
7
Q
What is somatic sensation? Give examples
A
Touch, pressure, temperature, proprioception, nociception
8
Q
What is visceral sensation? Give examples
A
Pressure/pain on internal organs
9
Q
What is specialized sensation? Examples?
A
Vision, hearing, taste, balance, smell
10
Q
What is perception?
A
Assigning meaning to sensation information
11
Q
What are the three ways to classify sensory receptors?
A
Location, Modality, Structure
12
Q
General senses can be classified as either ______ or ______
A
Somatic & visceral
13
Q
What are exteroreceptors? Example ?
A
Respond to stimuli originating in external
Situated at or near body surfaces
Exam ; receptors in the skin/ thermoreceptoes
14
Q
What are interoreceptors?
A
Respond to changes in bodies internal environment
Visceral, interoreceptors; detect changes with an internal organs
Somatic interoreceptors found within Muscoskeletal, detect changes in bones and muscles
15
Q
What are thermoreceptors?
A
Sense changes in temperature
16
Q
What are chemoreceptors ?
Ex?
A
Sense changes in chemicals
Example ; smell ,taste , blood, gases
17
Q
What are mechanoreceptors?ex?
A
Sense stress and changes in pressure , gravity, cell volume shape / position, touch itch and movement
Example; propioreceptors
18
Q
What are nocireceptors ?
A
Send tissue damage, physical, or thermal injury
19
Q
Receptor _____ helps determine stimulus duration
A
Adaptation
20
Q
Adaptation is ?
Example?
A
- decreased sensitivity to continuous stimulus
ex: eyes adjusting to dark room, not noticing/feeling shoes after wearing them for a couple hours
21
Q
Tonic receptors show how limited _____ is
A
adaptation
22
Q
Tonic receptors ?
Ex?
A
respond continuously
Ex: head position receptors in inner ear; all pain receptors
23
Q
What are phasic receptors?
Ex?
A
they adapt rapidly; only respond to new stimuli
ex: pressure receptors
24
Q
Sensory unit ?
A
sensation generated by a sensory neuron and all its receptors
25
Receptive field?
area of a surface covered by a single sensory unit
a larger sensory field means it is harder to localize the stimulus
26
_______ detect sensations of cold and heat ...
thermoreceptors
27
Transient receptor potential (TRP) channels
open at different temperatures and release Calcium to detect temperature changes in humans
28
What are the 4 general features of nociceptors?
Nociceptors are concentrated in areas more prone to injury
Absent from brain and sparse on most internal organs
very slowly or non-adapting
respond to cellular damage, noxious chemicals and signals released by the body itself
29
Nociceptors respond to which four types of pain?
Fast pain
Slow pain
Acute pain
Chronic pain
Visceral pain
30
What are special senses? (5)
Smell
Taste
Sight
Hearing
Balance
31
What is the function of eyebrows?
Provide shade and inhibit sweat
32
What is the function of eyelids (palpebrae) with conjunctiva?
spreads oil, mucus, and saline
33
function of conjuncitva?
thin transparent mucous membrane
34
function of palpebral fissure?
space between eyelids
35
Function of canthi?
lateral and medial, eyelids meet
medial canthus has caruncle with modified sweat and sebaceous glands
36
Function of eyelashes?
Double/triple row of hairs. Tarsal glands at inner margins produce sebum & allow eyelids to be airtight when closed
37
What is the lacrimal gland's function?
produces tears
38
What is the process of tear formation and excretion?
tears begin in lacrimal gland and drain from lacrimal puncta at corners of eyes into the lacrimal sac where the fluid will be drained into the nasal cavity via the nasolacrimal duct
39
Superior rectus function ?
Upward movement of eye
40
Inferior rectus function?
downward movement of eye
41
Superior oblique function?
downward and lateral movement of eye
42
Inferior oblique function?
upward and lateral movement of eye
43
lateral rectus function?
Lateral rotation of eye
44
Medial rectus function?
medial rotation of eye
45
What is the white outer layer of the eye called?
Sclera
46
What is the function of the sclera?
maintains shape, protects internal structures, provides muscle attachment point, continuous with cornea
Has dense collagenous connective tissue w/elastic fibers. Collagen fibers are large and opaque
47
What is the transparent window continuous anteriorly with the sclera called?
cornea
48
What is the cornea? made of? water content? function?
connective tissue matrix containing collagen, elastic fibers, and proteoglycanas
layer of stratified squamous epithelium on the outer surface. Collagen fibers are small, thus transparent
More proteoglycans than sclera, low water content (water would scatter light)
Avascular, transparent, allows light to enter eye; bends and refracts eye
49
What is the white part of the eye called?
the sclera
50
What is the pigmented part of the eye called?
Iris
51
What is the central opening that allows light to enter called?
pupil
52
What structure in the eye helps focus light on the retina?
Lens
53
What is the vascular layer of the eye called?
Choroid
54
Which structure in the eye contains photoreceptor cells that capture light?
RETINA
55
_______ is the central point of the retina
macula
56
the ________ is center of field of view; contains highest density of rods and cones
Fovea
57
Opic nerve function
carries visual information to the visual cortex
58
What is the refraction of light in general?
the change of light speed from one medium to another causes it to bend
59
What is the refraction of light in the eye?
convex lens refracts light so it converges on a focal point (the retina)
60
________ allows proper focusing of light
accommodation
61
Accommodation allows proper focusing of light: list the two muscles and brief summarize
Ciliary muscles contract> suspensory ligaments loosen> lens relaxes into thicker shape>increased refractive power
Ciliary muscles relax> suspensory ligaments remain taut> lens pulled into flatter position> decreased refractive power
62
What are the two eye issues that can occur when lens elasticity decreases with age?
Myopia or hyperopia
63
What is visual acuity?
the ability to focus an image on the retina
64
What is myopia? Corrected by?
Nearsigthedness; cornea/lens is too powerful or eyeball is too long
correct by concave lens
65
what is hyperopia ? corrected by ?
farsightedness; cornea/leans is too weam or eyeball is too short
corrected by convex lens
66
What is presbyopia?
increase in near point of vision w age due to less flexible lens?
67
What is astigmatism?
corena/lens are not uniformly curved so light rays do not focus at single focal point
68
What are the layers of the retina? bottom to top?
Sclera, choroid, photoreceptor layer (rods and cones) , nuclear layer, outer plexiform, bipolar layer (inner nuclear) , inner plexiform, ganglionic layer
69
Ganglionic cells are filled with ?
Pigment melanopsin
70
Ganglion cells are 1-3% _____, which have the following functions (list functions)
PHOTOSENSITIVE
Functions include:
Help reset internal clock
Help regulate pupil size
Help regulate release of melatonin
71
The retinal pigement epithelium (RPE) contains ?
Stores and recycles?
Contains melanin and traps unused photons not captured by photoreceptors
Stores and recycles vitamin A
72
which two structures of the eye are photoreceptor cells?
RODS AND CONES
73
what are photoreceptors? What do they do?
cells in the retina that detect light and affect color perception
74
Scotopic VS photopic vision?
Rod cells contain rhodopsin
They are for scotopic vision meaning they function optimally under low light conditions/ with shades of gray and black
Cone cells contain opsin
They are for photopic vision; meaning they function optimally under intense, bright light conditions
75
Rods are _____ photoreceptor cells which are ____ and _____ vision
bipolar; black and white vision
76
Rods are found over most of retina, but not in ____. They are more sensitive to ____ than cones
FOVEA; LIGHT
77
Protein _____ changes shape when struck by light; and eventually separates into its two components: _____ & _____
rhodopsin
OPSIN & RETINAL
78
Retinal can be converted to _____ __ from which it was originally derived.
VITAMIN A
79
Rods are unusual sensory cells; when not stimulated they are _____________
Lights causes them to ________
depolarized
Hyperpolarize
80
How does light and dark adaptation work?
adjustment of eyes to changes in light. happens because of changes in amount of available rhodopsin, pupil reflexes, and changes in level of photoreceptor function
81
cones are bipolar ______ cells that are responsible for _____ vision and _____ acuity
receptor
responsible for color vision and visual acuity
82
cones is numerous in ?
fovea and macula lutea
83
Visual pigment for cones is called ?
Opsin: three types that respond to blue, red, and green light
84
Which photoreceptor type is specialized for photopic vision?
CONES
85
The ____ helps direct sounds
Auricle
86
which structure of the ear directs sound waves to tympanic membrane?
External acoustic meatus
87
which structure of the ear has three bones that transmit from the tympanic membrane to the oval window of the cochlea?
Auditory ossicles
88
oval window?
transmits sound waves to cochlea
89
cochlea?
contains hair cells; responds to sound vibrations
90
round window?
allows fluid in cochlea to move/ vibrate
91
semicircular canals?
detect angular acceleration
92
auditory tube?
connects w nasal passages
93
What is the transmission of sound from the outer to inner ear?
Sound waves are captured by outer ear and sent to inner via tympanic membrane .... tympanic vibrations push on malleus>incus> stapes; moves oval window ....... oval window transmits vibrations to scala vestibuli.............. basilar membrane moves, as well as the hair cells in the organ of corti
94
what is responsible for hearing?
Inner hair cells
95
What regulates tension on basilar membrane (ear) ?
outer hair cells
96
What is a hair bundle?
sterocilia of one inner hair cell
97
What is a tip link ?
attaches tip of each sterocilium in a hair bundle to the side of the next longer sterocilium
as sterocilia bend, they open K+ gates
98
Balance is involved w what structures of ear?
cupula and utricle and saccule
99
Movement of hair cells within the cupula (3) ... what happens?
Hair cells stick up into ampulla and are submerged in jelly-like substance (cupula)...
as head rotates, fluid surroundings cells lags behind
Causes hair cell movement in opposite direction to head movement
100
Movement of hair cells within the utricle and saccule ... what happens?
Hair cell of utricle and saccule are covered by gelatinous substance
cotnains embedded calcium carbonate cyrstals called otoliths
when head moves, otoliths pull gelatinous substance and sterocilia in direction of gravity
101
Which of the following occurs when stereocilia move in the direction of the kinocilium?
Ion channels open, cations flow into cell, depolarization
102
Axons of _____ ______ carry olfactory information to the cortex
MITRAL CELLS
103
Bundles of synapses between sensory neurons and mitral cells ?
glomerulus
104
Olfactory stem cell replace old ??
sensory neurons every few months
105
olfactory sensory neurons function?
cilia protrude downward into nasal cavity; axons project upwards and synapse with mitral cells
106
olfaction is ?
detecting smells
107
What is olfaction? (6)
detecting smells
sniff repeatedly or breathe deeply
mucus contains odorant-binding proteins
- olfactory sensations begin when odorant bind to protein and protein sitmulates receptor cell (rapidly adapting receptor)
Secondary neuron conducts signals to various CNS areas
- cerebral cortex
108
Which part of the brain perceives, identifies smell?
cerebral cortex
109
Which part of brain has visceral reaction to smell?
hypothalamus
110
which part of brain has smell recognition/ emotional reaction
amygdala
111
Papillae means ?
bumps on tongue that contain taste buds
112
taste receptor cells contain?
molecular components required for taste sensation
113
transitional cells are supporting cells between?
taste receptor cells
114
Basal cells function?
replace old taste receptor cells
115
Taste pore function?
trap dissolved food molecules and activate taste hair receptors
116
gustatory transduction is dependent on the type of ?
taste receptor involved
117
What are the four taste receptors?
umami amino acids ,
sugars/fructose/glucose/ artificial sweetners,
bitter/quinine/salcicin tannins,
sour/citric/tartaric acetic acids
