Pathophysiology of Pain

Question 1

what does pain change in the animal’s physiology and behavior to do?

Answer 1

reduce or avoid the damage
reduce likelihood of its recurrence
promote recovery

Question 2

what is nociception?

Answer 2

noxious/harmful stimuli are encoded by the peripheral nervous system and transmitted to the CNS (spinal cord and brain)

Question 3

what are the types of noxious stimuli?

Answer 3

mechanical
chemical
thermal

Question 4

what are the primary sensory neurons?

Answer 4

Abeta
Adelta
C

Question 5

what do primary afferents do?

Answer 5

carry message from periphery to dorsal horn of spinal cord

Question 6

where does serotonin act on the second order neuron?

Answer 6

reticular formation
raphe nucleus magnus

Question 7

where do second-order neurons synapse?

Answer 7

thalamus

Question 8

what happens in primary hyperalgesia?

Answer 8

decreases threshold
increases frequency response
decreases in response latency
spontaneous firing

Question 9

what types of pain cause central sensitization?

Answer 9

chronic pain
neuropathic pain

Question 10

what does neuropathic pain arise from?

Answer 10

injury to peripheral or central nervous system tissues

Question 11

what do nociceptors do?

Answer 11

convert noxious stimulus into an action potential

Question 12

what are Abeta neurons?

Answer 12

large, myelinated
low-threshold mechanical
touch, pressure

Question 13

what are Adelta neurons?

Answer 13

small, myelinated
low-threshold mechanical or thermal
high threshold mechanical or thermal
touch, temperature, pain

Question 14

what are C neurons?

Answer 14

small, unmyelinated
high threshold thermal, mechanical, chemical
polymodal nociceptors
“silent” nociceptors
postganglionic sympathetic, touch, temperature, pain

Question 15

what are the post-synaptic inhibitory neurotransmitters?

Answer 15

GABA
glycine

Question 16

how does perception occur?

Answer 16

second-order neurons synapse in thalamus
third-order neurons relay information to sensory cortex and limbic system

Question 17

which type of pain has no protective or healing purpose, but is a disease?

Answer 17

pathologic

Question 18

what does physiologic pain do?

Answer 18

protective
promotes healing
essential for survival

Question 19

what are the types of pain?

Answer 19

nociceptive
inflammatory
somatic
visceral
neuropathic
functional/neuroplastic

Question 20

when should nociceptive pain be temporarily halted?

Answer 20

surgery and other painful procedures
should not be chronically turned off

Question 21

can inflammatory pain become maladaptive?

Answer 21

yes- if persists chronically

Question 22

which sensitization does inflammatory pain initiate?

Answer 22

peripheral
central

Question 23

what is hyperalgesia?

Answer 23

amplified pain in response to noxious stimuli

Question 24

what is amplification in central sensitization?

Answer 24

neurons not normally associated with pain evoke pain

Question 25

what is plasticity?

Answer 25

the ability of the CNS to reorganize

Question 26

what happens in wind-up?

Answer 26

low level and higher frequency afferent stimulation release glutamate that leads to AMPA
continued: upregulates AMPA which leads to moree NMDA

Question 27

what leads to loss of inhibition?

Answer 27

death pf inhibitory interneurons

Question 28

is visceral pain caused by cutting or burning?

Answer 28

not usually

Question 29

what type of response is visceral pain associated with?

Answer 29

strong emotional and autonomic response

Question 30

which species are thought to experience pain?

Answer 30

mammals
fish
birds
reptiles
amphibians
some invertebrates

Question 31

what are the consequences of pain?

Answer 31

autonomic reflexes
generalized stress response
cardiovascular
anorexia, nausea, gastric ulceration, ileus
insomnia, behavior changes
immune response impairment/impaired wound healing