Transmission of Sensory Information: From Receptor Flashcards
1
Q
what are the 3 neuron pathways of the somatosensory system
A
first order neuron, second order neuron, third order neuron
2
Q
from receptors (sensory end organs) via primary affect fibers to DRG
A
first order neuron
3
Q
where does the DRG then send sensory information
A
dorsal horn
4
Q
second order neurons send information from where to where
A
spinal cord or brain stem to thalamus
5
Q
a collection of cell bodies that relay information to the parietal lobe
A
thalamus
6
Q
third order neurons send information from where to where
A
thalamus to cerebral cortex and cerebellum
7
Q
means crossing point
A
decussation
8
Q
what are the 2 types of conscious sensation
A
special sense and somatic senses
9
Q
what are the two types of subconscious sensation
A
somatic and visceral
10
Q
is the changing the form of a stimulus
A
transduction
11
Q
what is the order of events that allow use to differentiate between senses
A
Stimulus at receptor
Generates potential
Threshold met
Action potential is afferent
Message from receptor to DRG
DRG to dorsal horn
Ascends thalamus
Somatosensory cortex
12
Q
what are the 3 characteristics of sensory receptors
A
selectivity, adaptation, receptive field
13
Q
sensory receptors only respond to one sensory stimuli and converts it to an electrical graded potential
A
selectivity
14
Q
if the stimulus is maintained the perception of a sensation may fade or even disappear even though the stimulus persists
A
adaptation
15
Q
examples of rapid adaptation
A
pressure, tough, smell
16
Q
examples of slow adaptation
A
pain, body position, chemical composition of blood
17
Q
area of the skin innervated by the primary affect; size of receptor depends on the specific type of receptor
A
receptive field
18
Q
what areas of the body have the smallest areas where sensory receptors are most dense
A
lips and finger tips
19
Q
what are the 6 ways to classify receptors
A
structure, source of stimulus, location, sensitivity, rate of adaptation, size of receptive field
20
Q
what are the two categories of classifying receptors by structure
A
free/diffuse nerve endings and encapsulated nerve endings
21
Q
what receptors are free/diffuse nerve endings
A
temp, tickle, temp, and some pain
22
Q
what receptors are encapsulated
A
pacinian corpuscle (pressure
23
Q
what are the 3 ways receptors can be classified by stimulus and location
A
exteroceptors, proprioceptors, interoceptors
24
Q
detect information from the external environment
A
exteroceptors
25
examples of exteroceptors
touch, smell, light, sound
26
where are exteroceptors found
in the skin
27
detect position sense and muscle tension
proprioceptors
28
where are proprioceptors found
muscles, tendons, joint capsule
29
detect changes within the internal environment of the body
interoceptors
30
examples of interoceptors
pH, BP, thirst, visceral pain
31
where are interoceptors found
walls of digestive structures, blood vessels, respiratory walls
32
what are the 4 types of receptors based on the type of stimulus energy
nociceptors, thermoreceptors, mehcanoreceptors, mechanoreceptors
33
what does nocere mean
to injury
34
free nerve endings found in skin, muscle, joints, and viscera
nociceptors
35
where are nociceptors most numerous
skin
36
small, myelinated and unmyelinated peripheral nerve fibers
nociceptors
37
what type of stimuli are nociceptors sensitive to
noxious
38
what type of nerve endings are most numerous in our body and aid in protection
free nerve endings
39
examples of stimuli for nociceptors
extreme thermal pain (above 45C and below 15C), sharp sensation (mechanical), chemical agents in blood or body fluids or external exposure
40
responds to heat or cold gradients
thermoreceptors
41
what type of nerve endings are thermoreceptors
free nerve endings
42
can thermoreceptors respond to both heat and cold
no, can either respond to hot or cold, never both
43
where are thermoreceptors found
skin, mucous/serous membranes, deep fascia, joints, connective tissue of organs
44
if hot/cold stimulus is outside the gradient for thermoreceptors, what receptors kick in to prevent injury
nociceptors
45
respond to substances released by cells, including damaged cells following an injury or infection
chemoreceptors
46
are chemoreceptors typically free N endings or encapsulated
encapsulated
47
examples of chemoreceptors
taste buds, olfactory receptors in olfactory epithelium, aortic and carotid bodies respond to changes in O2 in blood, CO2 receptors in the medulla/aortic/carotid bodies, gut receptors that regulate blood glucose/amino/fatty acids in the stomach and intestines
48
respond to mechanical deformation by touch (course/crude/light), pressure, stretch, vibration
mechanoreceptors
49
hairy
non-glaborous skin
50
hairless
glabrous skin
51
transmits touch (course/crude/light), pressure, tickle, itch, movement of skin
superficial cutaneous mechanoreceptors
52
examples of superficial cutaneous mechanoreceptors
Hair follicle endings
Meissner's corpuscles
Merkel's disks/merkel cell-neurite complex
Raffini
Pacinine
53
found in hair/nonglabrous skin
hair follicle endings
54
what is the stimuli for hair follicle endings
bending of the hair
55
hair follicle endings are ______ afferent axons and ______ adapating
myelinated AB and rapidly
56
are encapsulated and are found at superficially at epidermal-dermal junction in glabrous skin areas
meissners corpuscle
57
meissner's corpuscles can adapt _____ and have a _____ receptive field
fast and small
58
stimuli for meissners corpuscle
rapid skin displacement (flutter, quick brushing of skin)
59
where are meissner's corpuscles most numerous
finger pads, lips, anterior tongue, toes
60
example of two point discrimination for meissner's corpuscles
braille
61
where are merkel cells founds
epidermis/dermis junctions
62
are single large myelinated AB afferent axons that may carry more information from more than one complex
merkel cells
63
are merkel cells founds on glabrous or nonglabrous skin
glabrous
64
are merkel cells slow or fast adapting
slow
65
stimuli for merkel cells and example
light, uniform or sustained pressure
Holding a pen
66
discriminative touch
Merkel cells
able to tell the difference between objects based on texture, shape, and edges of objects
67
able to recognize something by touch
stereognosis
68
ability to recognize symbols that are traced on the skin/palm
graphesthesia
69
where are ruffini endings found
subcutaneous skin in both glabrous and nonglabrous skin
70
encapsulated and unmeylinated terminal of a myelinated AB afferent
raffini endings
71
are raffini endings slow or fast adapting
slow
72
stimuli for raffini endings
stretch receptor for collagenous stretching (skin and joint capsules) --- respond to skin drag
73
most deep and most distributed subcutaneous mechanoreceptor
pacinian corpuscles
74
egg-shaped, concentric layers of connective tissue with extracellular fluid in the spaces between
pacinian corpuscles
75
where are pacinian corpuscles found
hands, feet, aponeuroses and tendon sheaths of skeletal muscles, fascial planes, periosteum, around ligaments, interosseous membrane, in muscles
76
each one has its own heavily myelinated peripheral N fibers
pacinian corpuscles
77
are pacinian corpuscles slow or fast adapting
fast
78
stimuli for pacinian corpuscles
onset and removal of pressure, vibration, tickle
79
primarily concerned with posture, position sense, proprioceptions, muscle one, speed and direction of movement
proprioceptors
80
where are proprioceptors located
muscles, tendons, joints
81
examples of proprioceptors
muscle spindles, golgi tendon organs, golgi type endings
82
what two components make up position sense
kinesthesia and proprioception
83
awareness of body/limbs in space during movement (rate and direction)
kinesthesia
84
awareness of static body/limbs in space
proprioception
85
sensory organ embedded in skeletal muscle
muscle spindle
86
are muscle spindles free nerve endings or encapsulated
encapsulated
87
what is the function of muscle spindles
provide info about the present length of muscle and the rate of change in length when a muscle is stretched
88
do muscle spindles contribute to bone movements
no
89
fire the entire time the muscle is being stretched
tonic stretch receptors
90
adapt to a constant stimulus and stop responding; respond briefly to a quick stretch
phasic stretch receptors
91
muscle spindles are _____ shaped, meaning they are tapered at the ends
fusiform
92
are specialized fibers inside the muscle spindle
intrafusal
93
are ordinary striated muscle fibers outside the muscle spindle
extrafusal
94
the ends of intrafusal fibers are connected to what
extrafusal fibers
95
intrafusal fibers can only contract where
at their ends
96
large, sack like, filled with nuclei in the center
nuclear bag fibers
97
single row or chain of nuclei, attach at either end of nuclear bag fibers
nuclear chain fibers
98
what are the two types of sensory axons that attach to muscle spindles
annulospiral endings and flower spray endings
99
annulospiral endings are primary sensory endings of type ____ afferents
Ia
100
wrap around the central region of the nuclear bad and nuclear chain
annulospiral ending
101
what type of stimuli do annulospiral endings respond to
tonic and phasic
102
flower spray endings are secondary sensory ending of type ___ afferents
II
103
end mainly on nuclear chain fibers adjacent to primary endings
flower spray endings
104
what type of stimuli do flower spray endings respond to
tonic only
105
as extrafusal fibers are stretched, ends of intrafusal fibers are stretched and primary and secondary afferents send information to the ____ to adjust muscle tone to fit the task
CNS
106
small myelinated axons that signals contraction of intrafusal fibers
gamma motor efferents
107
what are gamma motor efferents under the control of
CNS (cell bodies in ventral horn of spinal cord)
108
relays tension in tendons
golgi tendon organs
109
encapsulated receptors found in tendons near the musculotendinous junctions
golgi tendon organs
110
respond to very slight changes in tension to both active muscle contraction and passive stretch
golgi tendon organs
111
golgi tendon organs send sensory information to the spinal cord by type ____ afferents
Ib
112
what provides the CNS with sensory information to allow normal muscle tone/muscle length tension relationship to be maintained
muscle spindles and golgi tendon organs
113
when a muscle contracts, what happens at muscle spindles and GTO
Spindles not stretched, do not fire
GTO fire under tension
114
what happens at muscle spindle and GTO when muscle is stretched
Spindles are stretched, increased sensory info to spinal cord
GTO under tension so also send sensory info
115
if muscle tension is too great or muscle is overstretched, the CNS will send inhibitory message to the ______ to tell muscle to relax
alpha motor neuron
116
respond to mechanical deformation of the capsule and ligaments
joint receptors
117
what type of endings in joint capsules signal extremes of joint ROM (type II afferents)
ruffini
118
what endings in joint capsules respond to movement
paciniform
119
are similar to GTO's and respond to tension of ligaments in joint capsules
ligament receptors
120
what is the end destination for sensory information in the brain
parietal lobe
121
where are somatic afferent receptors found
skin, joints, muscles
122
examples of somatic afferents
pain, temp, light touch, discriminative touch, pressure, vibration, tickle, itch, sexual
123
where are visceral afferent receptors found
glands, organs, vessel walls, membranes
124
examples of visceral afferent information
pain, stretch, pressure, chemical changes
125
how are somatic afferents classified
by axon diameter and conductance velocity
126
are large axons that carry information from muscles, tendons and joints
large afferent axons
127
myelinated, largest and fastest axons; come from muscle spindles and stimulated by muscle stretch
Ia/Aa somatic afferents
128
myelinated, large and fast axons; carries sensory information from GTO's, ligament receptors, and Ruffini endings; stimulated by tendon or ligament tension
Ib somatic afferents
129
carries information from joint capsules, muscle spindles, cutaneous touch, stretch, and pressure receptors
medium sized afferents
130
myelinated, medium sized; carries information from muscle spindles, meissners and pacinian corpuscles, ruffini and hair follicle endings
II/AB sized afferents
131
what stimulated II/AB medium afferents
stimulated by muscle stretch, joint movement, touch, pressure, skin stretch and vibration
132
carries information from MSK systems and skin about crude touch, pain and temp
small diameter afferents
133
what are examples of small diameter afferents
Adelta and C
134
myelinated, small and fast; carry sensory from hair follicles and free nerve endings; pain, cold temp, crude touch
Adelta afferents
135
unmyelinated, small and slow; carries motor into to glands, smooth mm; slow, burning, throbbing, aching pain, warm temp, smell, itch, tickle
C afferents
