Pain and Management Flashcards
1
Q
xwhat is the definition of Nociception
A
Nociception: the activation of neural pathways by stimuli that damage or threaten to damage tissues
2
Q
what is the definition of Noxious Stimulus:
A
Noxious Stimulus: potentially damaging stimulus.
3
Q
what is a Nociceptive stimulus:
A
Nociceptive stimulus: a stimulus that activates nociceptive pathways
4
Q
what is the sensation for nociception
A
pain
5
Q
what is the sensation for thermoreception
A
hot and cold
6
Q
what is the sensation for mechanoreception
A
touch
7
Q
what is the sensation for proprioception
A
position sense
8
Q
what is the sensation for gustation
A
taste
9
Q
what is the sensation for olfaction
A
smell
10
Q
when you have pain radiated in healthy areas of the body. what is this called
A
referred pain
11
Q
give an example when some pains, may not be painful
A
tumours
12
Q
being born with a condition which, allows you to feel no pain can be dangerous. what is the name of this condition
A
congenital insensitivity
13
Q
what is dentoalveolar pain
A
pain of the tooth and its surroundings
14
Q
what is dentine sensitivity
A
when there is an increase sensitivity stimulus to the dentine, this is a result of erosion of the enamel.
15
Q
what is reversible pulpitis
A
: occurs when there is inflammation of the pulp, however this inflammation can be reversed.
16
Q
what is irreversible pulpitis
A
occurs when inflammation to the pulp causes vessel and nerve damage beyond repair.
17
Q
what is periapical periodontitis
A
is an acute or chronic inflammatory lesion around the apex of a tooth root which is usually caused by bacterial invasion of the pulp of the tooth.
18
Q
what is acute pericoronitis
A
is inflammation of the tissue surrounding a third molar. The condition most often occurs in molars that are partially impacted, or not fully visible. Most people with pericoronitis have a flap of gum tissue partially covering the crown of the erupting tooth.
19
Q
what is a dry socket
A
: occurs when you have had a permanent tooth extracted and a blood clot fails to develop at the site of extraction. Or it dislodges or dissolves before the wound has healed. Causing allot of pain.
20
Q
what is maxillary sinusitis
A
is the inflammation of the maxillary sinuses. The symptoms are usually a headache.
21
Q
how are blocked salivary glands formed
A
salivary stones as a result of crystallized saliva block saliva ducts and direct the flow saliva back to the gland, causing it swell, resulting in pain.
22
Q
which receptor is a a sense organ or cell that responds to mechanical stimuli such as touch or sound
A
mechanoreceptor
23
Q
which receptor is a a sensory receptor for painful stimuli
A
nociceptors
24
Q
where does perception of the stimuli occur
A
cerebral cortex
25
where is the stimulus processed before it is reaches the cerebral cortex
thalamus
26
what is a synapse
a synapse is gap between nerve pathways
27
there are two electrical potentials for signalling the body. what are they?
graded potential
action potential
28
which electrical potential is used for long and short distance
short distance: graded potential
long distance:action potential
29
where do the graded potential occur in a nerve
at the nerve endings
30
what can change the charge of the cellular membrane of the neuron
neurotransmitter molecules released from other neurons
and environmental stimuli
31
The lipid bilayer membrane that surrounds a neuron is impermeable to charged molecules or ions. how do ions enter/exit
via special proteins called ion channels
32
Ion channels that change their structure in response to voltage are called?
voltage gated ion channels
33
The difference in total charge between the inside and outside of the cell is called the?
membrane potential
34
what is the function of the sodium potassium pump
* Uses ATP
* Transports sodium out of the cell
* Transports potassium in to the cell
* Ratio: 3Na+ out for every 2K+ in
* Helps maintain concentration gradient
35
which ion is more permeable K+ or Na+
K+
36
Chemical gradient allows for K+ to flow out.
electrical gradient caused by what keeps the K+ inside to cause equilibrium
neagtively charged protein anion
37
what is nernst equation (equilibrium potential for K+ =)
-90mV
38
what is the equilibrium potential fo Na+
+60mV
39
will resting membrane potential be nearer to K+ or Na+ equilibrium potential
K+
the ion with greater membrane permeability will drive membrane potential
40
what does this image indicate
Image indicates that resting membrane potential has been achieved.
This is the equilibrium between the NA+ and K+ and is indicated at -70mV
41
what does this image indicate
Due to a stimulus from either a graded potential or a current from an APs.
It results in the rapid change. Due to an increase in positive gradient outside, the voltage gated Na+ channels rapidly open and increase its intake of Na+ ions.
The inside of the cell becomes more positive. This is indicated at -50mV
42
what does this image indicate
Due to the rapid influx of the Na+ ions, this causes a rapid depolarisation overshoot.
43
what does this picture indicate
As the depolarization peaks, this results in the depolarization of the cell.
K+ channels start to open after delay
As a result, the Na+ channels are now closed and inactivated.
The rapid outflux of K+ results in repolarization.
44
what does this picture indicate
Due to the rapid outflux of the K+ the threshold value reaches hyperpolarization.
Here we will begin to see the K+ channels close.
And the Na+ channels reset.
45
what does the image indicate
the cell has reached resting membrane potential.
Membrane will become permeable to K+.
The K+ will be closed
46
how does Local Anaesthesia work
Anaesthesia chemical compound works by moving in to the neuron and then sitting in the N+ channels.
This blocks the channels, thus blocking action potential propagation.
47
can an action potential occur, during absolute refractory period
no
## Footnote
Na+ channels not in their resting configuration (-50mV)
48
can an action potential occur, in relative refractory period
The K+ channels are open
Membrane is hyperpolarised (increased in negativity)
An action potential can occur, but it requires a larger stimulus.
49
what does an increase in axon width do.
* Results in lower resistance and faster conduction
50
does myelination increase or decrease speed of transmission
increase
* Myelin sheath: acts as insulator
* Node of Ranvier – exposed axon – ion channels
* Local currents flow node to node
* Depolarisation jumps from node to node.
51
which nerve fibres are associated with nociception
C nerve fibres
alpha delta nerve fibres
52
what is the function of afferent neurons
carry sensory signals from the body to the brain (input neurons)
53
what is the function of Efferent neurons:
carry signals from the brain, such as those directed towards the muscles in the body.
54
what is dorsal
Dorsal: on or relating to the upper side or back of an animal, plant, or organ
55
what is ventral
Ventral: on or relating to the underside of an animal or plant; closer to the abdominal.
56
what are first order neurons
first order neurons conduct impulses from receptors of the skin and from proprioceptors (receptors located in a join, muscle or tendon) to the spinal cord or brain stem, where they synapse with second-**order** neurons
57
what are second order neurons
Second order neurons: the second-order neurons carry signals from the spinal cord to the thalamus (these neurons are generally located in the brain stem or spinal cord).
58
what are third order neurons
Third order neurons: the third-order neurons carry signals from the thalamus to the primary sensory cortex.
59
what is Somato (somatosensory):
relating to the human or animal body.
60
how many roots does the trigeminal nerve have
two roots
sensory and motor
61
The trigeminal sensory nuclear complex consists of the following:
* Nucleus oralis
* Nucleus interpolaris
* Nucleus caudalis
* Main sensor nucleus
62
If there was damage to the nucleus caudalis or a V tractotomy, what would you experience:
Loss of ipsilateral facial pain, hot/cold
Still fee touch
63
what is trigeminal neuralgia
is a chronic pain condition that affects the trigeminal nerve, which carries sensation from your face to your brain
64
what occurs at nucleus oralis
Carry nociceptive inputs to N. Oralis, especially from teeth
Possibly the site of synapses for oral + dental pain
65
what occurs at nuclear interpolaris
reflexes
66
what occurs at nuclear caudalis
Synapses for facial pain and hot/cold
Possibly the site of synapse for oral + dental pain
67
what is transduction
Transduction: transduction in the nervous system typically refers to stimulus-alerting events wherein a physical stimulus is converted into an action potential, which is transmitted along axons towards the central nervous system for integration.
68
* All or none event
* Propagates along a nerve
* Voltage gated channels
these are examples of what
action potentials
69
* Local change in membrane potential
* Triggering event in – synaptic, post synaptic membrane
* Triggering event in – receptor, action of stimulus
* These triggers respond to mechanical, chemical or thermal gated channel
these are examples of what
graded potential
70
action potential vs graded potential
trigger = depolarisation to threshold
action potential
71
action potential vs graded potential
trigger = stimulus neurotransmitter
graded potential
72
action potential vs graded potential
ion movement = Na+ then K+ through voltage gated channels
action potential
73
action potential vs graded potential
net movement of Na+ K+ Cl- or Ca2+
graded potential
74
action potential vs graded potential
coding of magnitude = all or none, frequency
action potential
75
action potential vs graded potential
coding of magnitude = size of potential changes
graded potential
76
action potential vs graded potential
duration = fixed
action potential
77
action potential vs graded potential
duration = variable
graded potential
78
action potential vs graded potential
propagation = self regenerating propagation
action potential
79
action potential vs graded potential
propagation = decays with distance
graded potential
80
action potential vs graded potential
refractory period = yes
action potential
81
action potential vs graded potential
refractory period = no
graded potential
82
action potential vs graded potential
direction of potential change = depolarisation then hyperpolarisation
action potential
83
action potential vs graded potential
direction of potential change = depolarisation or hyperpolarisation
graded potential
84
action potential vs graded potential
location = voltage gated channels
action potentials
85
action potential vs graded potential
location = receptors and post-synapse
graded potential
86
which receptors convert stimulus energy to elctrical energy
graded potential receptors
87
what is transduction
transduction is the conversion of a sensory stimulus to another.
88
what activates TRPV4
temperatures greater than 27 degress
89
what activates TRPV3
temperatures greater than 31 degrees
90
what activates TRPV1
\>45°C
capsaisin
91
what activates TRPV2
\>50°C
92
what does this picture indicate
Image indicates that a strong stimulus must occur in order for an action potential to occur.
93
what do these drugs act on
* Glutamate
* GABA (gamma-aminobutyric acid)
* Acetylcholine
* Serotonin
* Noradrenaline
Many drugs act at synapses and affect the neurotransmitters that relay between the synapses
94
what is Temporal summation
occurs when a high frequency of action potentials in the presynaptic neuron elicits postsynaptic potentials that summate with each other. This allows the membrane potential to reach the threshold to generate an action potential.
95
what is Spatial summation:
Spatial summation is the effect of triggering an action potential in a neuron from one or more presynaptic neurons. This occurs when more than one excitatory postsynaptic potential (EPSP) originates simultaneously and a different part of the neurone
96
* Pain is associated with two speeds. Fast and slow.
which nerve fibres are responsible for fast , sharp pain
alpha delta nerve fibres
97
* Pain is associated with two speeds. Fast and slow.
which nerve fibre is associated with slow, burning pain
C nerve fibres
98
which nerve fibre has a conductive velocity of 5-30ms
alpha delta nerve fibres
99
which nerve fibre has a conductive velocity of 0.2-2ms
c nerve fibres
100
what do polymodal c fibre nociceptors respond to
respond to all pain stimuli
101
what do alpha delta mechanical nociceptors respond to
respond to strong mechanical stimuli
102
what do alpha delta polymodal nociceptors respond to
responds to all types of noxious stimuli
103
what is carried to the trigeminal nuclei
Primary afferent sensations are carried from the periphery to the trigeminal nuclei. These are known as 1st order neurones.
104
which order neurons transcend from the trigeminal nuclei to the thalamus
2nd order neurons
105
3rd order neurones transcend from where
thalamus to the cerebral cortex
106
what acts as a relay for the thalamus for nociceptive stimulus
ventrobasal nuclei
107
where does perception occur
cerebral cortex
108
where does processing occu
thalamus
109
where does detection occur
at receptors
110
what is divergence
Any individual neuron can make divergent connections to many different postsynaptic cells.
111
what is convergence
One postsynaptic cell receives convergent input from a number of different presynaptic cells.
Convergence allows a neuron to receive input from many neurons in a network
112
what does this image show
**Discrete pain image shows the following:**
If there is a noxious stimulus in a specific area. It follows the same pathway from the primary afferent to the 2nd order neurones
It also diverges on to another postsynaptic cell.
113
what does this image show
**Hyperalgesia image shows the following:**
2nd order neurones can be sensitised by external factors (prostaglandin, serotonin)
As a result of this sensitised, they transmit a bigger signal to the consciousness along with the other 2nd order neurones.
This causes an increased in pain referred to as hyperalgesia.
114
what does this image show
**radiating image shows the following:**
2nd order neurones can be sensitised by external factors (prostaglandin, serotonin)
As a result of this sensitised, they transmit a bigger signal to the consciousness along with the other 2nd order neurones.
This causes an increased in pain area. Which means pain can be perceived as originating from a larger area than the stimulus area.
115
what does this image show
**Referred image shows the following:**
2nd order neurones can be sensitised by external factors (prostaglandin, serotonin)
As a result of this sensitised, they transmit a bigger signal to the consciousness along with the other 2nd order neurones.
The consciousness can perceive the location of the pain site somewhere else.
Usually deep to superficial structure:
* Heart to left arm
* Maxillary sinus to teeth
* Appendix to abdominal skin
116
How does chemical signalling work over different distances?
What speed does it work at?
Short distance (e.g. synapse)
Long distance (e.g. hormones)
Relatively slow
117
How does electrical signalling work over different distances?
At what speed does it work at?
over short distances by **graded** potentials
over long distances by **action** potentials
very fast- up to 120m/s or around 270mph
118
what are two properties of copper wire? how do they make it an excellent conductor?
1. covered by a great **insulator**: plastic
2. copper is an excellent conductor of electricity
This means that electricity is conducted rapidly by copper, and is not lost to the external environment because the plastic coating seals it in
119
why are nerves not as good as copper wire?
What do we need to improve conductivity?
membrane is a poor insulator in an aqaeous environment
cytoplasm is a relatively poor conductor
Signal decays over a **short distance** (2-3mm), bad as nerves can be longer than a metre
This means we need a propagrating material: action potential
120
