Sensory Physiology Flashcards
1
Q
specialized cells & receptors transmit ______ energy to Vm
A
environmental
2
Q
what are the (2) general categories in sensory reception?
A
internal and external
3
Q
internal sensory reception
A
blood pressure, osmolality, pH, position and balance
4
Q
where do signals go in internal sensory reception?
A
subconscious brain (brain stem,hypothalamus)
5
Q
external sensory reception
A
light/vision, sound/hearing, smell, taste, touch
6
Q
where do signals go in external sensory reception?
A
conscious brain (cortex)
7
Q
what are chemoreceptors?
A
taste, smell (external): CO2, pH (internal)
8
Q
what are thermoreceptors?
A
hold and cold
9
Q
what are mechanoreceptors?
A
touch, pressure, hearing
10
Q
what are photoreceptors?
A
light
11
Q
what are nociceptors?
A
pain (other receptors can also cause if stimulated intensely)
12
Q
what are proprioceptors?
A
allows delicate muscle and tendon movements (tells brain what muscles are doing without having to see the movement)
13
Q
what are cutaneous receptors?
A
skin –> hot, cold, pain, touch
14
Q
what are tonic receptors?
A
continuous AP as long as stimulus present
15
Q
what are phasic receptors?
A
burst of AP when stimulus 1st applied, then gradually decreases
16
Q
what is an example of tonic receptor?
A
vision
17
Q
what is an example of a phasic receptors?
A
smell
18
Q
what is sensory adaptation?
A
touch (like not feeling the pressure of the clothes on your body)
19
Q
what happens when a sensory receptor senses stimulus?
A
it depolarizes
20
Q
what must the sensory receptor reach threshold to generate?
A
AP
21
Q
what is the thalamus apart of?
A
forebrain
22
Q
what does the thalamus act as?
A
relay center for most senses
23
Q
what does the thalamus process?
A
information and passes on to correct area of brain (sound to auditory cortex)
24
Q
two sensory transduction
A
ionotropic and metabotropic
25
what is ionotropic?
cause direct opening of ion channels (stretch or ligand gated)
26
what sensory transduction is quick-to-start, short-lasting?
ionotropic
27
what sensory transduction is slow to start and longer lasting?
metabotropic
28
what is metabotropic?
chemical binds to GPCR
29
what is another word for touch?
somatosensation
30
what does skin sense?
heat, cold, pressure, touch, pain
31
what are receptors?
naked dendrites of specialized neurons
32
what are Ruffini endings?
sustained pressure
33
what are merkel's discs?
sustained touch and pressure
34
what are meissner's corpuscles?
texture, vibrations
35
what are Pacinian corpuscles?
deep pressure and vibration
36
what are nociceptors?
damage in cells and pain
37
what is the physiological word for touch?
somatosensation
38
what does touch cause the opening of?
stretch gated ion channels causing depolarization
39
what does the sensory cell equal?
neuron
40
what touch sensors are phasic?
Meissner & Pacinian corpuscles
41
what touch sensors are tonic?
merkels discs and Ruffini endings
42
spinal & cranial nerves (touch) -->
thalamus --> somatosensory cortex
43
what is the receptive field in two-point touch threshold?
area of skin that, when stimulated, changes the firing rate of a neuron
44
what does the area (size) depend on in the receptive field?
number of neurons in location
45
what is two point touch threshold?
minimum distance at which two points of touch can be perceived as separate
46
what is lateral inhibition?
when a blunt object touches the skin and the middle area is stimulated more than the edges
47
what do sensory neurons in the center of lateral inhibition inhibit?
sensory neurons nearby
48
what is another word for taste?
gustation
49
what does the tongue sense?
tastants via taste buds
50
what are taste buds?
randomly placed modified epithelium that can be replaced if damaged
51
do all the taste cells in a single taste bud sense the same tastant?
YES!
52
What are the six categories of taste?
Salty (Na+), Sour (H+), Bitter, sweet, umami (meat, savory), chalky (Ca++)
53
what is the chain of taste buds to the brain?
taste buds -> cranial nerves -> thalamus -> gustatory cortex
54
what are salty (Na+) and sour (H+)?
ionotropic
55
what are bitter, sweet, and umami?
metabotropic
56
what is another word for smell?
olfaction
57
what is the stimulus for smell?
odorants in the air
58
what does smell have?
- epithelium lining the nasal cavity contains neurons expressing 100s of different receptors
- chemosensory
- sensory cell = neuron
- random distribution of receptors
59
can cells in the nose be replaced if damaged?
YES!
60
what do dendrites in smell have?
non motile cilia, PM on cilia have receptors
61
is smell metabotropic or ionotropic?
metabotropic
62
what is the chain for smell?
Olfactory receptor neurons -> olfactory bulb -> olfactory tract -> olfactory cortex
63
what does the smells chain not go through?
thalamus
64
what other brain region does smell connect to?
limbic system and hippocampus
65
what is another word for hearing?
Audition
66
what does the outer ear do in hearing?
funnels amplified sound waves
67
what does the middle ear do in hearing?
transmits sound waves to inner ear
68
what are the three bones in the ear for hearing?
malleus, incus, stapes
69
what does the inner ear do for hearing?
senses sound waves and transmits signal
70
what are sound waves sensed by?
hair cells lining the cochlea of the inner ear
71
what does the spiral organ (or organ of Corti) do?
converts sound into AP
72
What is hearing?
ionotropic and tonic
73
what kind of hair cells do the ears contain?
modified epithelium
74
where does hearing rest on?
basilar membrane
75
what kind of hair protrude into what kind of membrane?
stereocilia protrudes into gelatinous tectorial membrane
76
what vibrates as sound waves pass through scala vestibuli?
basilar membrane
77
what kind of gated channels do stereocilia cells have?
stretch gated K+ channels
78
when surrounded in fluid high in K+, what rushes in?
K+
79
what is the auditory pathway?
hair cell of basilar membrane -> auditory nerve => brainstem -> thalamus -> auditory cortex
80
what is balance and equilibrium sensed by?
vestibular apparatus
81
what are the three that help balance and equilibrium?
utricle, saccule, semicircular canals
82
what do balance and equilibrium in the ear have?
it is mechanosensory, ionotropic, and tonic
83
what does the inner ear have a larger of?
kinocilium
84
what happens when stereocilia are bent towards kinocilium?
depolarization
85
what happens when stereocilia are bent away from kinocilium?
hyperpolarization
86
what are otolith organs?
stereocilia of hair stick out into a gelatinous otolith membrane containing CaCo3 crystals
87
what happens when the crystals give a great mass?
moves during accelaration
88
what does the utricle do?
horizontal acceleration (slamming on breaks)
89
what does the saccule do?
vertical acceleration (elevator)
90
what law is the movement of the otolith connected to?
law of interia
91
what movement does the head do when the semicircular canals move anteriorly?
shake head yes
92
what movement does the head do when the semicircular canals move laterally?
shaking head no
93
what movement does the head do when the semicircular canals move posteriorly?
cartwheels
94
where are hair cells located?
in ampulla at the base of each canal
95
where are stereocilia embedded?
in a gelatinous membrane called the cupula
96
pathway of balance and equilibrium
hair cells -> vestibular apparatus -> vestibular portion of auditory nerve -> brain stem -> thalamus -> cerebellum
97
what is the cause of vertigo?
when AP frequency from one inner ear is different than the other one
98
what is another word for vision?
photoreception
99
what do the cornea and lens do?
refract and focus light on retina
100
what does light stimulus lead to the release of?
ligand
101
what does the release of ligand do?
stimulates AP
102
what is vision?
photosensory and tonic
103
what are the two photoreceptors?
rods and cons
104
list what you know about rods
- very sensitive to light
- useful in dim light
- outnumber cones 9:1
105
list what you know about cones
- 3 kinds (red, blue, green)
- enriched in the fovea
- less sensitive to light
- useful in bright light
- color discrimination
106
what is dark current?
constant flow of ions occurring in photoreceptors in the dark
107
photoreceptors are slightly____ in the dark
deporlarized
108
what does light cause ligand-gated Na+ channels through activation of a GPCR?
it causes it to close
109
what is photosensation?
hyperpolarization, rhodopsin, metabotropic
110
what is fovea centralis made up of?
all cones
111
what do optic discs not have?
cones or rods
112
what is it called when a light is shined on the optic disc?
blind spot
113
do rods or cones have better acuity/detail, and why?
cones, because it has no convergence
114
what is the visual pathway?
rods & cones -> intermediate neurons -> optic nerve -> thalamus -> visual cortex
