Core Sensory System Flashcards
(85 cards)
1
Q
sensory system consists of
A
receptors afferents tracts and sensory cortex
2
Q
sensory information arrives at the brain as
A
action potential
3
Q
types of sensory information arrives at the brain
A
- type of sensation ( modality )
- site of stimulation ( locality )
- strength of simulation ( intensity )
- duration of simulation
4
Q
difference between somatic and autonomic
A
- somatic nervous system transmits sensory and motor signals to and from cns autonomic nervous system controls the function of our organs and glands and can be divided into the sympathetic and parasympathetic divisions.
5
Q
sensation carried by a somatic afferent neuron
A
somatic sensation
6
Q
sensation carried by an autonomic afferent neuron
A
visceral sensation
7
Q
what information do autonomic neurons carry
A
information that does not reach the consciousness i.e. lung inflation bp blood ph etc
8
Q
example of somatic afferent neuron sensation that do not reach consciousness
A
information regarding muscle length and muscle spinal from golgi tendon organ
9
Q
specialised structures found at the peripheral end of afferent neurons
A
sensory receptors
10
Q
traditional classification of sensory receptors are
A
- special senses hearing vision smell taste rotational and linear acceleration - cutaneous senses touch pressure cold warmth pain - visceral sneses receptors in internal structure
11
Q
classification according to site of sensory receptors are
A
- telereceptors : visual receptors ( distant events )
- exteroceptors : touch receptors (external environment )
- interoceptors : chemoreceptors ( internal environment )
- proprioceptors : detect change in position of body
12
Q
classification according to type of stimulus
A
mechanoreceptors thermoreceptors nociceptors chemoreceptors barorecptors
13
Q
classification according to structure of nerve ending
A
- free nerve ending
- encapsulated
- expanded tip
- sense organs
14
Q
example of free nerve endings
A
pain (non adapting) and temperature receptors (intermediatly adapting)
15
Q
example of encapsulated nerve endings
A
pacinian corpuscles and meissners corpuscles
adapt rapidly
16
Q
receptor for touch is called
A
pacinian corpuscles
17
Q
receptor for vibration is called
A
meissners corpuscles
18
Q
example of expanded tip nerve endings
A
merkles discs and ruffinin endings
slow adapting
19
Q
when receptors form with non neuronal cells the form
A
sense organs
20
Q
example of sense organs
A
organ of corti - hearing
otolithic organ - posture
21
Q
classification according to degree of adaptation
A
- rapidly adapting
- slowly adapting
- non adapting
22
Q
properties of receptors
A
adequate stimulus excitability adaptation
23
Q
adequate stimulus
A
energy receptor is most sensitive too i.e. visual receptors and electromagnetic energy
24
Q
stimulation of receptors results in
A
receptor potential
25
proprioceptors
ruffini endings
26
carry nerve impulses from the receptors or sense organs towards cns
afferent neurons
27
somatic afferent neurons enter the spinal cord through
the dorsal roots and their cell bodies located in the dorsal root ganglia
28
conduct impulses from receptors in skin skeletal muscle tendons joints and parietal layers of the pleura and peritoneum
somatic afferent neurons
29
conduct impulses from smooth and cardiac muscles and from baroreceptors chemoreceptors volume receptors and taste buds
autonomic afferent neurons aka visceral receptors aka
30
autonomic afferent neurons enter the spinal cord through
enter through the dorsal root and cell bodies are located in dorsal root ganglia or the equivalent ganglia in cranial nerves 7 9 10
31
integrates all visceral information located in brain stem
nucleus of tractus solitaires (NTS)
32
which tract carries visceral pain to sensory cortex
spinothalamic tract like somatic pain
33
afferent neurons according to degree of myelination
- thick myelinated type A
- thin myelinated type B
- non myelinated type C
34
types of type A thick myelinated neurons
- A alpha ( 70 - 120 )
- A beta ( 30 - 70 )
- A gamma ( 15 - 30 )
- A delta ( 12 - 30 )
35
less rapidly conducting neurons cv is ( 3 - 15 )
type B thin myelinated neurons
36
slowly conducting neurons cv is ( 0.5-2 )
type C non myelinated neurons
37
rapidly conducting neurons
type A thick myelinated neurons
38
receptors for proprioception and touch use which fibres
type A beta fibers
39
receptors for pain and visceral sensation use which fibres
type A delta or C fibers
40
the two types ascending pathways in white matter of spinal cord
dorsal column tract aka lemniscal tract
| spinothalamic tract aka anterolateral tract
41
carries fine touch pressure vibration position sense and two point discrimination
dorsal column tract aka lemniscal tract
42
neurons of dorsal column tract aka lemniscal tract
afferent type A beta fibers
43
carries crude touch temperature pain sexual sensation and itching sensation
spinothalamic tract aka anterolateral tract
44
neurons of spinothalamic tract aka anterolateral tract
afferent type A or C fibers
45
how many order neurons are present in each sensory tract pathway
three
46
where is dorsal column tract first order neuron
cell bodies in dorsal root ganglia
47
where is dorsal column tract second order neuron
cell bodies in the gracile and cuneate nuclei in the medulla ( decussation at medulla oblongota )
48
carries sensory information from the lower half of the body entering the spinal cord at the lumbar level
gracile fasciculus
49
carries sensory information from the upper half of the body (upper limbs, trunk, and neck) entering the spinal cord at the cervical level
cuneate fasciculus
50
what event takes place at second order neuron of dct
axons cross to opposite side and ascend in the medial lemniscus until the reach the specific nuclei of the thalamus ( the venture-posterior nuclei of the the thalamus VPNT ) synapse with third order neuron
51
where is dorsal column tract third order neuron
cell bodies in thalamus (VPNT) axons ascend in the sensory radiation to reach sensory cortex
52
where is spinothalamic tract first order neuron
cell bodies in the dorsal root ganglia
53
route of dorsal column tract into spinal cord and out
axons pass from the receptors to the spinal cord ascend in the dorsal white matter of the spinal cord until they reach the medulla where they synapses
54
route of spinothalamic tract into spinal cord
axons pass from the receptors to the spinal cord they enter the gray matter in the posterior horn of the spinal cord where they synapse with the second order neuron
55
where is spinothalamic tract second order neuron
cell bodies in the posterior horn of the spinal cord
56
what event takes place at second order neuron of stt
axons cross to the opposite side in front of the central canal of spinal cord and ascend in the white matter until they reach the specific nuclei of the thalamus (VPNT)
57
where is spinothalamic tract third order neuron
cell bodies in the thalamus (VPNT)
58
what event takes place at second order neuron of stt
axons ascend in the sensory radiation to reach sensory cortex
59
which neurones are damaged in syringomyelia
neurons of the spinothalamic tract
60
sensory signs of syringomyelia include
loss of pain and temperature but intact touch vibration and position sensation
61
site that receives sensory tracts
sensory cortex
62
all types of sensation reach the brain in the form
action potential
63
first or fast pain
pricking pain
64
second or slow pain
burning pain
65
first or fast pain is transmitted through which fibres and releases which neurotransmitter
type A delta fibers and glutamate
66
second or slow pain is transmitted through which fibres and releases which neurotransmitter
type C fibres and substance P
67
tissue damage releases
pps pain producing substance
68
which laminae form the substantial gelantinosa
laminae 2 and 3 regarded as gate for pain
69
activates contralateral S1 and secondary S2 sensory areas
pain
70
used to treat pain
thalamotomy
71
types of pain
cutaneous slow and fast receptors type A delta and C
deep somatic slow C
visceral C
72
feature of deep somatic and visceral pain
referred pain
73
convergence theory
afferent neurones carrying pain from viscus and afferent neurons from skin dermatome meet at spinothlamic second order neuron and both go up brain perceives both as pain and localise the pain in the skin dermatome
74
facilitation theory
collateral of impulses from viscus and regular dermatome
75
inhibit pain
gate control and theory opiate system of the brain
76
synthesis of this is highly increased during stress
opioids
77
opioids include
encephalins and endorphins
78
synthesised within dorsal root ganglion
opioids
79
opioids mechanism in dorsal horn
opioid receptors respond to opioids cause presynaptic inhibitor of type c fibers inhibit release of substance P and closes pain gate
80
opioids mechanism in peripheral tissue
respond to opioid peptides immune cells relieve pain
81
opioids mechanism in peraqueductal are in midbrain
receptors in midbrain respond to encephalinins to activate deciding tract to release serotonin which mediates closing of pain gate
82
which is more cold receptors or hot receptors
cold 4:10 ratio
83
temperatures the receptors respond to
cold receptors - 10 - 38
| heat receptors - 30 - 45
84
fibres of temperature receptors
cold receptors - type A delta and C
| heat receptors - type C
85
fibres of proprioception
type A beta into dorsal column tract
