Anatomy & Physiology of Pain II Flashcards
How can neuropathic pain occur due to C-fibre nociceptor pathway malfunctioning? [1]
Interneurons (lamina II) can spontaneously become active & fire pain
Noxious pain terminates where in dorsal root horn? [1]
Non-noxious pain terminates where in dorsal root horn? [1]
Noxious pain: early laminas
Non-noxious pain: deep laminas
Specifically, where do axons that transmit pain and form the spinothalamic tract decussate in the spinal cord? [1]
Anterior white commissure
Label A
White anterior commissure
Transmission (spinothalamic tract)
Anterior spinothalamic tract projects what type of information / pain? [2]
Lateral spinothalamic tract projects what type of information / pain? [3]
Anterior spinothalamic: crude touch, tickle, pressure, itch
Lateral spinothalamic : pain & temperature
Which of the folliwng numbers identify where the anterior and lateral spinothalamic tracts run in the spinal cord? [2]
5a: lateral spinothalamic tract
5b: anterior spinothalamic tract
Transmission (Anterior Spinothalamic Tract)
Which fibres project within the Anterior STT?
Where does the Anterior STTT project to after travelling up the spinal cord / wheres the third order neurone? [1]
Ab, Ad and C fibres
Projects to ventral posterior lateral (VPL) and ventral posterior inferior (VPI) nucleus of the thalamus. (VPL/VPI) on the contralateral anterior STT tract
Third order neurones from VPL/VPI project to the somatosensory cortex (S1 and S2) - Provide exact localisation and physical intensity of noxious stimulus.
Transmission (Lateral Spinothalamic Tract)
Which fibres project within the Lateral STT?
Describe its path
Ad and C fibres
Projects contralaterally via LSTT to mediodorsal nucleus of the thalamus (MDvc) and posterior thalamus (VPI and VMpo).
From mediodorsal nucleus of the thalamus (MDvc) innervates anterior cingulate cortex (ACC)
From posterior thalamus (VPI and VMpo) which innervates the rostral insula (unpleasant emotion of pain)
Anterior STT: innervates the [] cortex via []
Lateral STT: innervates the [] & [] via the [] and []
Anterior STT
* Innervate the primary and secondary somatosensory cortex via VPL/VPI
Posterior STT:
* Innervates the anterior cingulate cortex and rostral insula via the mediodorsal nucleus of the thalamus (MDvc) and posterior thalamus (VPI and VMpo)
The unpleasantness (painfull) character of pain is mediated via pain to which are the brain? [1]
Limbic systems
[] spinothalamic tract controls affective-motivational dimension of pain (i.e. unpleasantness)
[] spinothalamic tract controls sensory-discriminative dimension of pain (i.e. intensity)
Lateral spinothalamic tract controls affective-motivational dimension of pain (i.e. unpleasantness)
Anterior spinothalamic tract controls sensory-discriminative dimension of pain (i.e. intensity)
Label A-E and their functions
Modulation (descending pathways - brain regions)
Label the brain regions involved in modulation of pain (A-C) and what type of neurones they have [6]
A: peri aqueductal grey (PAG): produces analgesia
B: Locus coerulus: contains descending noradrenergic neurons
C: Raphe nucleus contains descending serotoninergic neurons
Explain the mechansim of pain modulation at the dorsal horn via the Noradrenaline and serotonin neurons
Noradrenaline and serotonin neurons descend from locus coerulus and raphe nucleus respectively & exhibit excitatory repsonse on lamina II neurons
The lamina II neurons present here are inhibitory - so release GABA and ekephalins onto the INCOMING Aδ neurons, which reduces their activity
Name three types of endogenous opoids and the receptors they can bind to [6]
Endogenous opoids:
* endorphins
* enkephalins
* dynorphins
Opoid receptors:
* Mu opioid receptor
* Delta opioid receptor
* Kappa opioid receptor
How does binding of endogenous opiod to opiod receptor inhibit pain? [2]
Causes a decrease in Ca2+ release at pre-synaptic terminal
This inhibits release of glutamate and stops pain modulation
How can you modulate pain via Abeta afferents? (e.g. if in pain - rubbing the area might help)
Ab afferent from skin also synapse excitably onto lamina II inhibitory cell body, that are used as interneurons from descending pain pathway (from noradrenaline and serotonin)
This causes more inhbitory GABA and enkephalins to be released on INCOMING Aδ neurons, which reduces their activity
What is a definition of chronic pain? [1]
Chronic pain is pain that last longer than 3 months despite treatment.
Chronic pain
What is allodynia and hyperalgesia?
Allodynia: a condition where pain is caused by a non-noxious (non-painful) stimulus (e.g. tickle with a feather).
Hyperalgesia: a condition where an abnormal increased pain sensitivity is caused by a noxious (painful) stimulus (e.g. hot water on sunburn).
Chronic pain
Explain what causes peripheral sensitisation?
During injury (esp. inflammation), chemical mediators (i.e. cytokines, H+) can activate nociceptors and activate intracellular signalling mechanism, which can up regulate ion channels, thus increase membrane potential closer to depolarisation threshold.
This makes the sensory primary afferent fibres more sensitive to activation.
Explain what causes central sensitisation
Continuous activation of the projection neurones can activate intracellular signalling mechanism, which can up regulate ion channels, thus increase membrane potential closer to depolarisation threshold.
This makes the projection neurones more sensitive to activation.
Peripheral sensitisation
Explain what ectopic and ephatic activation of nocifibres are
In peripheral sensitisation:
Ectopic activation: spontaneous activation of fibres causing pain
Ephatic: lateral contact causes generation of AP on neighbouring fibre and cause pain
Central sensitsation of pain
Explain what Abeta fibres collateral sprouting-induced pain is [1]
Abeta fibres (which dont normall cause paincan sprout in dorsal horn - which directly activates projection neurons which causes chronic pain
Which of the following would detect a change in pH?
ASICs
TRPM8
Nav1.7
TRPV1
Which of the following would detect a change in pH?
ASICs
TRPM8
Nav1.7
TRPV1
Which of the following would detect the cooling effect of this sweet?
ASICs
TRPM8
Nav1.7
TRPV1
Which of the following would detect the cooling effect of this sweet?
ASICs
TRPM8
Nav1.7
TRPV1
Which of the following would detect the heating effect of this food?
ASICs
TRPM8
Nav1.7
TRPV1
Which of the following would detect the heating effect of this food?
ASICs
TRPM8
Nav1.7
TRPV1 aka capsaicin receptor
Which of the following serve to receive and transmit information primarily relating to acute pain?
Aα
Aγ
Aδ
Aβ
C
Which of the following serve to receive and transmit information primarily relating to acute pain?
Aα
Aγ
Aδ
Aβ
C
Which of the following serve to receive and transmit information primarily relating to touch?
Aα
Aγ
Aδ
Aβ
C
Which of the following serve to receive and transmit information primarily relating to touch?
Aα
Aγ
Aδ
Aβ
C
Which of the following serve to transmit information primarily relating to pain, temperature and itch.
Aα
Aγ
Aδ
Aβ
C
Which of the following serve to transmit information primarily relating to pain, temperature and itch.
Aα
Aγ
Aδ
Aβ
C
Which of the following serve to transmit information primarily relating to proprioception (muscle sense)
Aα
Aγ
Aδ
Aβ
C
Which of the following serve to transmit information primarily relating to proprioception (muscle sense)
Aα
Aγ
Aδ
Aβ
C
Which of the following serve to transmit information relating to this image?
Aα
Aγ
Aδ
Aβ
C
Which of the following serve to transmit information relating to this image?
Aα
Aγ
Aδ
Aβ
C
Which of the following serve to transmit information relating to this image?
Aα
Aγ
Aδ
Aβ
C
Which of the following serve to transmit information relating to this image?
Aα
Aγ
Aδ
Aβ
C
Mutations in which of the following would cause this diease?
ASICs
TRPM8
Nav1.7
TRPV1
Mutations in which of the following would cause this diease?
ASICs
TRPM8
Nav1.7 Congenital insensitivity to pain (CIP):
TRPV1
Name the gene codes for receptor that allows development of neuron growth factor [1]
TRKA gene codes for TrKA receptor: causes NGF to be rpoduced
Which of the following is key in modulation of pain and empathy
Anterior cingulate cortex
Prefrontal cortex
Insula
Amygdala
Which of the following is key in modulation of pain and empathy
Anterior cingulate cortex
Prefrontal cortex
Insula
Amygdala
A 56-year-old right-handed man is brought to the emergency department 90 minutes after acute-onset right arm weakness, difficulty forming words, and sustained dizziness. His past medical history is significant for well-controlled type 2 diabetes and hypertension. A CT head without contrast demonstrates no acute hemorrhage or lesion, but shows an area of hypodensity and associated mild parenchymal swelling deep within the left peri-Sylvian fissure. Which of the following vessels is most likely implicated in the etiology of this patient’s current condition?
A. M1 segment of the middle cerebral artery
B. A2 segment of the anterior cerebral artery
C. A3 segment of the anterior cerebral artery
D. M2 segment of the middle cerebral artery
A 56-year-old right-handed man is brought to the emergency department 90 minutes after acute-onset right arm weakness, difficulty forming words, and sustained dizziness. His past medical history is significant for well-controlled type 2 diabetes and hypertension. A CT head without contrast demonstrates no acute hemorrhage or lesion, but shows an area of hypodensity and associated mild parenchymal swelling deep within the left peri-Sylvian fissure. Which of the following vessels is most likely implicated in the etiology of this patient’s current condition?
A. M1 segment of the middle cerebral artery
B. A2 segment of the anterior cerebral artery
C. A3 segment of the anterior cerebral artery
D. M2 segment of the middle cerebral artery insula is supplied by the M2 MCA
Which of the following is A
Anterior cingulate cortex
Prefrontal cortex
Insula
Amygdala
Which of the following is A
Anterior cingulate cortex
Prefrontal cortex
Insula
Amygdala
Which of the following is the amygdala
A
B
C
D
E
Which of the following is the amygdala
A
B
C
D
E
Which of the following modulates pain by releasing seratonin on descending pathways?
PAG
Locus coeruleus
Raphe nucleus
Amygdala
Reticular formation
Which of the following modulates pain by releasing seratonin on descending pathways?
PAG
Locus coeruleus
Raphe nucleus
Amygdala
Reticular formation
Which of the following modulates pain by releasing noradrenaline on descending pathways?
PAG
Locus coeruleus
Raphe nucleus
Amygdala
Reticular formation
Which of the following modulates pain by releasing noradrenaline on descending pathways?
PAG
Locus coeruleus
Raphe nucleus
Amygdala
Reticular formation
Label A-C
A: Peri-aqueductal grey (PAG)
B: Locus coeruleus
C: Raphe nucleus
Label A & B [2]
A: allodynia
B:hyperalgesia
