Pain

Question 1

Causes of loss of pain

Answer 1

nerve damage, loss of fingers, diabetes

Question 2

Describe pain

Answer 2

discriminative sensation, graded motivation

Question 3

What are the two theories for pain

Answer 3

specificity, convergence

Question 4

Describe the specificity theory

Answer 4

pain is distinct - specific receptors

Question 5

describe convergence theory

Answer 5

pain is integrated - convergent activity, distributed network

Question 6

Describe nociceptors

Answer 6

afferent, free nerve endings

Question 7

How are nociceptors classified

Answer 7

according to stimulus, fibre type and conduction velocity

Question 8

What are the two fibre types in nociceptors

Answer 8

lightly myelinated a-delta, un-myelinated c fibres

Question 9

Characteristics of a-delta fibres

Answer 9

fast, mechano sensitive, mechano thermal sensitive

Question 10

What do C fibres detect

Answer 10

mechanical, thermal, chemical

Question 11

Which fibre is slowest

Answer 11

C fibres

Question 12

How can fast pain be mimicked

Answer 12

direct stimulation of a-delta fibres

Question 13

How can slow pain be mimicked

Answer 13

stimulation of C fibres

Question 14

Where is the capsaicin receptor active

Answer 14

nociceptive a-delta and c fibres at 45C

Question 15

What do the capsaicin receptors respond to

Answer 15

heat

Question 16

What does capsaicin mimic

Answer 16

endogenous vanilloids released by stress tissues

Question 17

What are the two central pain pathways

Answer 17

sensory discriminative, affective motivationl

Question 18

describe the sensory discriminative pathway

Answer 18

signals intensity, location of stimulus

Question 19

What does the affective motivational pathway signal

Answer 19

unpleasantness

Question 20

What tract does the discriminative pain pathway involve

Answer 20

spinothalamic tract - anterolateral system

Question 21

Measurement of what activity correlates to the intensity of pain

Answer 21

somatosensory cortex activity

Question 22

What regions elicit an emotional response to pain

Answer 22

insult and cingulate cortex

Question 23

What is hyperalgesia?

Answer 23

increased response to a painful stimulus

Question 24

Example of hyperalgesia

Answer 24

hypersensitive damaged skin

Question 25

What is Allodynia?

Answer 25

painful response to normal stimuli

Question 26

Example of allodynia

Answer 26

painful sensitivity of sunburnt skin

Question 27

What is the function of bradykinin

Answer 27

affects function of nociceptive molecular receptors

Question 28

What is the effect of prostaglandins

Answer 28

lower threshold for axon potential generation

Question 29

What is COX important for?

Answer 29

prostaglandin synthesis

Question 30

Which painkillers act on COX

Answer 30

aspirin, ibuprofen

Question 31

Where are prostaglandins released

Answer 31

dorsal horn

Question 32

What causes hyperpathia

Answer 32

fibre or axonal loss

Question 33

what is hyperpathia

Answer 33

detection threshold for pain is raised

Question 34

What is the result of hyperpathia

Answer 34

extreme pain in response to normal stimulus

Question 35

What diseases are associated with hyperpathia

Answer 35

shingles, diabetes, MS

Question 36

What does phantom limb pain indicate

Answer 36

bodies central representation isnt passive

Question 37

What do mechanoreceptors inhibit

Answer 37

nociceptive C fibres - spinal cord

Question 38

What do enkephalins inhibit

Answer 38

pain fibres

Question 39

What are enkephalins

Answer 39

endogenous opioid family peptides

Question 40

Which phenomena do not fit with specificity theory of pain

Answer 40

phantom limb, placebo effect, referred pain