exam 9 - pain and pleasure

Question 1

What are the 3 main types of pain?

Answer 1

• nociceptive
• neuropathic
• inflammatory

Question 2

nociceptive pain

Answer 2

• signals that tell you that are are damaging or about to damage your skin
• different types respond to heat, chemicals, severe pressure, and cold

Question 3

neuropathic pain

Answer 3

• caused by damage to CNS such as brain damage caused by a stroke and repetitive movements which cause conditions like carpal tunnel syndrom

Question 4

inflammatory pain

Answer 4

injury activates immune cells that release inflammatory mediators. These increase activity of nociceptors and increase pain transmission in the spinal cord.

Question 5

Pain relief by tactile stimuli (gate control)

Answer 5

• the spinal cord has a gate that can turn/close off the ascending pain signal
• we have several gates/filters/modulators of pain in the spinal cord

Question 6

Where does input into the gate come from?

Answer 6

• tactile stimuli
• pain
• central control

Question 7

tactile stimuli

Answer 7

• mechanoreceptors
• info from touch cells are able to turn the gate off

Question 8

pain

Answer 8

• nociceptors
• ex.) if you have pain in one hand and then get pain in the other, the pain processing can get turned down

Question 9

central control

Answer 9

• information from cognitive factors from the cortex
• information from the brain through descending pain modulation is able to close the gate

Question 10

capsaicin

Answer 10

• activates heat-pain channels
• ingesting massive doses of it after activating them can desensitize them (no longer able to release substance P which is used as pain relief)

Question 11

What can capsaicin lead to?

Answer 11

long term pain relief

Question 12

What was used to differentiate the brain areas that are associated with intensity/quality of pain and pain emotion?

Answer 12

• MRI imaging can tells us where neural activity is occurring
• allows us to see that pain sensation and pain emotion are processed in different areas

Question 13

What brain regions are associated with the intensity/quality of pain?

Answer 13

primary somatosensory and secondary somatosensory cortices

Question 14

What brain regions are associated with the intensity/quality of pain emotion?

Answer 14

insula and anterior cingulate cortex

Question 15

How do analgesic drugs inhibit pain?

Answer 15

• drugs such as opiates work through of pain modulation systems
• opiates act at all different levels to turn down the signaling/transmission of ascending pain information

Question 16

How do opioids work?

Answer 16

• opioids (or endorphins) bind to opioid receptors
• binding activates descending pain control mechanisms which reduces transmission of pain signals

Question 17

How does perception (attention) alter pain perception?

Answer 17

• distracting an individual can reduce pain intensity
• though it does not change much of pain emotion

Question 18

How does mood alter pain perception?

Answer 18

• changing mood reduces the unpleasantness of pain (emotional aspect)
• does not affect the intensity of pain

Question 19

What do MRI brain images show in regards to attention and pain?

Answer 19

• more activation in the primary somatosensory cortex when attending to pain
• less activation when you are distracted

Question 20

What do MRI brain images show in regards to mood and pain?

Answer 20

• negative mood activates anterior cingulate cortex
• good mood reduces activation in anterior cingulate cortex

Question 21

How does chronic pain change the brain?

Answer 21

• chronic pain patients have reductions in brain gray matter in the cortex, specifically in brain regions involved in pain modulation
• loss of cells in that area makes it harder to modulate pain
• also have reduced opioid binding which makes it harder to activate pain relief

Question 22

What lifestyle intervention has been shown to decrease pain and stress?

Answer 22

• yoga has been shown reduce pain perception and higher pain tolerance
• people who do yoga have thicker gray matter
• people who exercise also have reductions in chronic pain