Nociception

Question 1

Adelta fibers

Answer 1

First pain fibers- 1st pain-

travels fast

Question 2

C-fibers

Answer 2

2nd pain fibers
travel slower
once these on the adleta fibers off
only discharge when stimulus is intense enough to cause damage

Question 3

TrpV1 receptor

Answer 3

Found in both Adelta and C-fibers
Activated by
-capsaicin- hot peppers
-heat
-acids
-anandamide
AP-Na gated channel

Question 4

Hyperalgesia

Answer 4

Enhanced sensitivity and responsivity to stimulation of area in and around damaged tissue

Sensitization of nociceptors by various substance release

Question 5

Bradykinin/histamine/prostaglandin release

Answer 5

Enhance the responsiveness of nociceptive endings

Question 6

Electrical signaling during nociception

Answer 6

stimulates local release of chemical substances

-substance P

Question 7

Substance P

Answer 7

Released during electrical activity in nociception

- cause vasodilation/ swelling/ release of histamine from mast cells

Question 8

How do NSAIDs work

Answer 8

Inhibit cyclooxygenase

- enzyme important for production of prostaglandins

Question 9

Brachial plexus evulsion

Answer 9

Pt feel burning pain in dermatomes corresponding to denervated area
- hyperactivity of dorsal horn herons in the deafferented region of the cord

Question 10

Lamina I neurons

Answer 10

High density of projection neurons that process pain info

-nociceptive specific– only excited by Adelta and C fibers

Question 11

Lamina V neurons

Answer 11

Receive info from mechanoreceptors and nociceptors

• wide dynamic range neurons
• respond to both somatosensory and noxious stimuli

Question 12

Why do we get referred pain

Answer 12

visceral and cutaneous nociceptors converge on same dorsal horn projection

Question 13

Periaqueductal gray PAG

Answer 13

Make excitatory connections in the rostroventral medulla

Question 14

Neurons in the Rostroventral Medulla

Answer 14

make inhibitory connections in Laminae I, II, and V of dorsal horn

Question 15

Inhibition of anteriolateral tract occurs how

Answer 15

Activation of enkephalin interneurons in the dorsal horn by administration of opiate substance to interact with the opiate receptors

• opiate receptors are on the nociceptive afferents and the dendrites of postsynaptic neurons
• inhibit the release of glutamate, substance P
• activation of opiate receptors is what suppresses the NT release