Pain

Question 1

Number of people with chronic pain in UK

Answer 1

7.8 million

Question 2

Amount spent of incapacity benifits due to chronic pain

Answer 2

£3.8 billion

Question 3

Nociceptive pain

Answer 3

response to tissue or inflammatory pathology with noxious stimuli

Question 4

Neuropathic pain

Answer 4

non functioning in the nervous system, such as nerve damage or ion channel changes

Question 5

Idiopathic pain

Answer 5

Brain areas causing pain

Question 6

Fibres associated with pain

Answer 6

C and A delta.

Question 7

How is nociception felt

Answer 7

Sensory endings in tissue activated by stimuli such as chemical, thermal, mechanical

Question 8

Where do pain fibres end

Answer 8

Grey matter of spinal chord, lamina 1 and II in superficial dorsal horn

Question 9

Name of superficial dorsal horn

Answer 9

substantia gelatinosa

Question 10

What NTs + Receptors do pain fibres release to next neurons in spinal chord

Answer 10

Glutamate and ATP.
Act on AMPA for immediate pain
NMDA for slower wind up of pain

Question 11

Name of tract from spinal chord to thalamus

Answer 11

Spinothalamic tract

Question 12

Where thalamus projects to

Answer 12

Cortex. Gives location and intensity

Question 13

Key area of decending control of pain

Answer 13

Periaqueductal grey in midbrain. Collects info from amny brain areas such as cortex, hypothalamus, amygdala

Question 14

Where does PAG project to

Answer 14

Rostroventral medulla, which then projects to dorsal horn.

Release 5HT which is excitatory and promotes pain throught 5HT 2/3 R

Question 15

Where does NA noicipetice pathway descend from

Answer 15

Locus coerulus. Limbic and RVM connect into it.

Question 16

What receptros are common in descending pathways

Answer 16

Endogenous opioid

Question 17

Central causes of pain sensitisation (4 - full names)

Answer 17

Substance P
NGF (Nerve growth factor)
BDNF (Brain derived neurotrophic factor)
CGRP

Question 18

How is NGF made

Answer 18

Made in peripheral tissues when tissues are damaged

Question 19

How does NGF work

Answer 19

Binds to TrkA receptor. This is a kinase linked receptor

Question 20

Activated TrkA downstream effects (4)

Answer 20

Increase in electrical activity
Chemosensitivity
Acts on genome in DRG cell body to release SP, CGRP, BDNF
Increase in ion channel expression - Na, P2X, TRPV1

Question 21

Antibody to TrkA receptor

Answer 21

Tanezumab

Question 22

Tanezumab uses

Answer 22

Effective in lower back pain
Good for OA
Causes joint damage

Question 23

BDNF receptor + location

Answer 23

TrkB on postsynaptic dorsal horn

Question 24

TrkB action

Answer 24

Phosphorylates NMDA subunit GluN1, sensitising the receptor for glutamate

Question 25

Lidocaine action

Answer 25

Blocks Na channels

Question 26

Na v 1.7 mutation problem

Answer 26

Can't feel pain

Question 27

What is inherited erythromyalgia

Answer 27

Na v 1.7 mutation Low threshold and enhanced response Causes attacks of burning and redness in extremites

Question 28

What is familial episodic pain syndrome

Answer 28

Mutation in TRPV1, Enhanced response to pain. Causes episodic upper body pain

Question 29

TRPV1 actions

Answer 29

Allows Na and Ca into the axons, increasing excitation

Question 30

Direct activators of TRPV1 (4)

Answer 30

Heat Capsasin Protons Endovanilloids

Question 31

Bradykinin release and receptor

Answer 31

Released by tissues in damage, acts on B2 receptor

Question 32

Bradykinin receptor action

Answer 32

Couples to PKC. | PKC phosphylates TRPV1, facilitating its opening

Question 33

Prostaglandins action

Answer 33

Bind to prostanoid receptor Activates PKA PKA inhinits K channels and keeps Na channels open

Question 34

TNF and IL1 in pain action

Answer 34

sensitise nociceptors

Question 35

ATP action in pain

Answer 35

Comes from damaged cells, | Acts on P2X 2 or 3 ion channels, which lets ions in

Question 36

What does the LC do?

Answer 36

Descending control over pain. NA acting at the alpha 2 adrenoreceptor gives inhibitory control

Question 37

Tapentadol mechanism of action (2)

Answer 37

Mu agonist | NA reuptake inhibitor