Unit 1 Somatic Senses Flashcards
(123 cards)
0
Q
All sensory systems mediate what 4 attributes of a stimulus no matter what type of sensation?
A
- Modality
- Location
- Intensity
- Timing
1
Q
Describe transduction
A
When a stimulus is changed into an electrical signal.
2
Q
What are the two systems of classifying nerve fibers?
A
Erlanger’s and Lloyds
3
Q
How does myelination effect conduction velocity?
A
Myelination increases conduction velocity by 6 fold
4
Q
An unmyelinated fiber 5 microns in diameter conducts a signal how fast?
A
5m/second
5
Q
How fast does a myelinated fiber 5 microns in diameter conduct a signal?
A
30m/second
6
Q
Using Erlanger’s system, what is the diameter of a type A alpha fiber?
A
8 to 20 microns
7
Q
Using Erlanger’s system, what is the diameter of type A beta fibers?
A
5 to 12 microns
8
Q
Using Erlanger’s system, what is the diameter of a type A gamma fiber?
A
2 to 8 microns
9
Q
Using Erlanger’s system, what is the diameter of a type A delta fiber?
A
1 to 5 microns
10
Q
Using Erlanger’s system, what is the diameter of a type B fiber?
A
1 to 3 microns
11
Q
Using Erlanger’s system, what is the diameter of type C fibers?
A
<1 microns
12
Q
Using Lloyd’s system, what is the diameter of type I fibers?
A
12 to 20 microns
13
Q
Using Lloyd’s system, what is the diameter of type II fibers?
A
4 to 12 microns
14
Q
Using Lloyd’s system, what is the diameter of type III fibers?
A
1 to 4 microns
15
Q
Using Lloyd’s system, what is the diameter of type IV fibers?
A
<1 micron
16
Q
Describe the labeled line principle.
A
The specificity of nerve fibers transmitting only one modality of sensation.
17
Q
Describe adaptation
A
When a neuron experiences a sustained stimulus it will show a decreased firing rate over time. This is known as adaptation.
18
Q
Describe slow adapting receptors
A
Continuous information relatively non adapting in response to a sustained stimulus
19
Q
Describe what fast adapting receptors do.
A
Fast adapting receptors react strongly when a change is taking place.
20
Q
Name two slow adapting receptors.
A
- Merkel’s discs
- Ruffini corpuscles
21
Q
Name two fast adapting receptors.
A
- Pacinian corpuscles
- Meissner’s corpuscles
22
Q
Describe the receptive field of Merkel’s Discs.
A
Merkel’s Discs have a punctate receptive field. Meaning its studded or marked with tiny dots or holes.
23
Q
How are Ruffini corpuscles activated?
A
Ruffini corpuscles are activated by stretching the skin.
24
What type of receptors are in the outer layer of the joint capsule?
Type I mechanoreceptors
25
Describe type I mechanoreceptors.
Type I mechanoreceptors are slow and low.
26
Describe type III mechanoreceptors.
Type III mechanoreceptors are slow and high.
27
Describe type II mechanoreceptors.
Type II mechanoreceptors are rapid and low
28
Describe type IV mechanoreceptors.
Type IV mechanoreceptors are nociceptors with a high threshold
29
What is an example of a type III mechanoreceptor?
Joint version of a golgi tendon organ.
30
This type of receptor fires dynamically with movement.
Type I mechanoreceptors
31
This type of receptor is completely immobile in inactive joints.
Type II mechanoreceptors
32
This type of receptor functions in joint movement monitoring
Type II mechanoreceptors
33
This type of receptor has a phasic effect on lower motor neuron pools.
type II mechanoreceptors
34
This type of receptor has a tonic effect of lower motor neuron pools
Type I mechanoreceptors
35
This type of receptor is completely inactive in physiologic normal joint. Instead they fire under increased capsule pressure and chemical irritation.
Type IV mechanoreceptors
36
What is stereognosis?
The ability to perceive form through touch.
37
What are our sensory modalities?
- pressure receptors
- cold receptors
- warmth receptors
- nociceptors
38
What type of receptor signals when hairless skin is ran over the edge on a object?
Meissner's Corpuscles
39
What type of receptor signals when subcutaneous tissue is run over the edge of an object?
Pacinian corpuscles
40
What type of receptor senses curvature of an object's surface?
Merkel's discs
41
What type of receptors are activated by stretching the skin?
Ruffini corpuscles
42
What are superficial receptors of the skin?
- Meissner's corpuscles
| - Merkel's discs
43
What are deep receptors of the skin?
- Pacinian corpuscles
| - Ruffini corpuscles
44
What are rapidly adapting receptors of the skin?
- Meissner's
| - Pacinian corpuscles
45
What are slowly adapting receptors of the skin?
- Ruffini corpuscles
| - Merkel's discs
46
Name the types of receptors of the skin that are activated by sustained pressure.
- Merkel's discs
| - Ruffini corpuscles
47
What types of receptors of the skin have a small receptive field?
- Meissner's corpuscles
| - Merkel's discs
48
What types of skin receptors have a large receptive field?
- Pacinian corpuscles
| - Ruffini corpusles
49
This type of skin receptor has a small receptive field and are activated by vibration.
Meissner's corpuscles
50
This type of skin receptor has a large receptive field and is activated by vibration.
Pacinian corpuscles
51
This type of receptor has a small receptive field and is activated by sustained pressure.
Merkel's discs
52
This type of receptor has a large receptive field and is activated by sustained pressure
Ruffini corpuscles
53
This type of receptor is superficial and rapidly adapting
Meissner's corpuscles
54
This type of receptor is superficial and slowly adapting
Merkel's discs
55
This type of receptor is deep and rapidly adapting.
Pacinian corpuscles
56
This type of receptor is deep and slow adapting.
Ruffini corpuscles
57
Most aspects of touch and proprioception come from what pathway?
Medial lemniscal system (dorsal column)
58
Sensations of crude touch, nociception, temperature, tickle, itch, and sexual sensation come from which pathway?
Anterolateral system
59
Where do 2nd order neurons in the medial lemniscal system (dorsal column) cross over?
Brain Stem
60
Where do 2nd order neurons in the anterolateral system cross over?
Spinal cord
61
Which side of the cord has a lesion of there is a loss of vibration and proprioception?
Ipsilateral
62
Which side of the cord has a lesion if there is a loss of sense of temperature (analgesia)
Contralateral
63
What brodman area forms muscles stretch receptors?
3a
64
What brodman area forms cutaneous receptors?
3b
65
What brodman area forms deep pressure receptors?
2
66
What brodman area forms rapidly adapting cutaneous receptors?
1
67
What type of neurons respond well to movement in all directions but not selectively to movement in any one direction?
Motion sensitive neurons
68
What type of neurons respond much better to movement in one direction than in another direction?
Direction sensitive neurons
69
What neurons respond best to movement along a specific axis?
Orientation sensitive neurons
70
Motion, direction, and orientation sensitive neurons are all neurons in which brodman areas?
1 and 2
71
What brodman area integrates tactile information from mechanoreceptors in skin with proprioceptive inputs from underlying muscles and joints?
Brodman area 5
72
What brodman area receives visual, tactile, and proprioceptive inputs?
Brodman area 7
73
Are thermoreceptors slow or rapidly adapting?
slow adapting
74
What is the range for extreme thermoreceptors?
50 degrees C
75
What are the three ways that nociceptors can be activated?
- mechanical
- thermal
- chemical
76
What are sensations of pain?
- pricking
- burning
- aching
- stinging
- soreness
77
What are the cardinal signs of inflammation?
Rubor - redness
Calor - heat
Tumor - swelling
Dalor - pain
78
What does potassium from damaged cells do to nociceptors?
Activates nociceptors
79
What does serotonin from platelets do to nociceptors?
Activates nociceptors
80
What does bradykinin from plasma kininogen do to nociceptors?
Activates nociceptors
81
What does histamine from mast cells do to nociceptors?
activates nociceptors
82
What do prostaglandins and leukotriends from ARA damaged cells do to nociceptors?
Sensitizes nociceptors
83
What does substance P from the primary afferent do to nociceptors?
Sensitives nociceptors
84
What type of fibers secrete both substance P and glutamate?
C fibers
85
This is responsible for slow pain
Substance P
86
Epicritic describes what pathway?
dorsal column - medial lemniscal system
87
Protopathic describes what pathway?
anterolateral system
88
This pathway is old phylogenetically and initiates actions.
Protopathic
89
This pathway is new phylogenetically and modifies actions.
Epicritic
90
Describe endogenous opioids from the pariaquedutal gray
enkephaline projections to Raphe
91
Describe endogenous opioids from the Raphe N.
Serotonin projections to the cord
92
What do inhibitory interneurons in the cord do?
Release enkephalin, inhibits C, A delta fibers and 2nd order projection neurons.
93
This nerve supplies most sensory innervation of head and face.
Trigeminal (C.N. V)
94
What type of muscle receptors respond to stretch?
Muscle spindles
95
What type of muscle receptors respond to tension?
Golgi tendon organs
96
These receptors are located withing the belly of the muscle parallel with extrafusal fibers
muscle spindles
97
This type of receptor is located at the junction of the muscle and tendon.
Golgi tendon organs
98
What type of receptor in innervated by two types of myelinated afferent fibers?
muscle spindles
99
What are two types of myelinated afferent fibers that innervate muscle spindles?
- Group Ia (large diameter)
| - Group II (small diameter)
100
What is the innervation of golgi tendon organs?
GTOs are innervated by group Ib afferent fibers
101
What happens when a spindle is activated by stretch of a muscle?
A muscle contraction
102
What happens when a GTO is stimulated by either a stretch or a contraction of a muscle?
Inhibition of muscle contraction
103
What type of muscle spindle is most responsive to muscle shortening?
group II
104
What type of muscle spindle is most responsive to muscle lengthening?
group Ia
105
What is the afferent innervation of a GTO
Group Ib
106
What is the afferent innervation of a muscle spindle?
Group Ia
| Group II
107
What is the efferent innervation of a GTO?
There is none.
108
What is the efferent innervation of a spindle?
y fibers
109
What are endogenous cannabinoids produced by the brain?
- anandamide
| - 2 arachidonoylglycerol (2-AG)
110
The production of this is increased during exercise and contributes to "runner's high"
Endogenous Cannabinoids
111
Relationship to extrafusal fiber of GTO
Series
112
Relationship to extrafusal fibers of spindle
parallel
113
What is the primary GTO stimulus?
Contraction (tension)
114
What is the primary spindle stimulus?
Stretch
115
What is the reflex response of a GTO
Inhibition of extrafusal fibers
116
What is the reflex response of a spindle
Contraction of extrafusal fibers
117
What innervates intrafusal fibers?
Gamma (y) motor system
118
Mesencephalic area appears to regulate rhythmic gate in what structure?
Reticular formation
119
What system facilitates gamma motor neuron antigravity control?
Vestibular system
120
Where do you find cutaneous sensory receptors?
Over skeletal muscle, sensory afferent activating gamma motor neurons
121
Describe spatial summation.
Increased signal strength transmitted by progressively greater number of fibers
122
Describe temporal summation
Increased signal strength by increased frequency of firing with the same number of fibers.
