Sensory 6: Pain Control

Question 1

what area is concidered the gateway to pain in the CNS

Answer 1

Substantia glatinosa of Rolandi (SGR)

Question 2

Enumerate endogenous opioids found in CNS

Answer 2

• Enkephalin
• Endorphin
• Dynorphin

Question 3

precursor of enkephalin

Answer 3

Pro-enkephalin

Question 4

Site of release of enkephalin

Answer 4

• Supraspinal: peri-aqueductal grey area (PGA)
• Spinal: SGR (substantia glatinosa of Rolandi)
• Limbic system (for well being)

Question 5

Precursor of Endorphin

Answer 5

pro-opio-melano-cortin

Question 6

Site of release of endorphin

Answer 6

• Hypothalamus: onto thalamus & PGA
• Pituitary gland

Question 7

Precursor of Dynorphins

Answer 7

Pro-dynorphin

Question 8

site of release of Dynorphins

Answer 8

Brain stem

Question 9

which Endongenous Opioid causes tolerence & addiction

Answer 9

Dynorphin

Question 10

Delta receptor has high affinity to

Answer 10

Enkephalin

Question 11

Mu receptors have high affinity to

Answer 11

endorphins

Question 12

Kappa receptors have high affinity to

Answer 12

Dynorphins

Question 13

Order of receptors according to their affinity towards opioids

Answer 13

1. Delta (enkephalin)
2. Mu (endorphin)
3. Kappa (dynorphin)

Question 14

Describe supraspinal descending analgesic system

Answer 14

1.Hypothalamus & pituitary gland release Endorphin–>** Periaqueductal grey area (PGA)**
2.Periaqueductal Grey area (PGA) releases Enkephalin—> Raphie magnus nucleus
3.Raphie magnus Nucleus releases serotonin–> Pain inhibtory interneurone
4.Pain Inhibitory Interneurone releases enkephalin —> SGR (substantia glatinosa of rolandi)
5.SGR prevent the release of substance P

In addition to collateral fibers from paleo-spinothalamic tract that further activate Periaqueductal grey area (PGA), therefore **Pain inhibits pain **

Question 15

Periaqueductal grey area is sensitive to

Answer 15

Endorphin (from thalamus & PG)

Question 16

periaqueductal grey Area secretes

Answer 16

Enkephalin (to Magnus raphie nucleus)

Question 17

Magnus raphie nucleus is sensitive to

Answer 17

Enkephalin (from PGA)

Question 18

Magnus raphie nucleus releases

Answer 18

Serotonin (to pain Inhibitory interneurone)

Question 19

Pain inhibitory Neurone is sensitive to

Answer 19

Serotonin (from Magnus raphie nucleus)

Question 20

Pain inhibitory interneurone secretes

Answer 20

Enkephalin (to SBR) to prevent releases of substance P

Question 21

Medical treatment of pain

Answer 21

Analgesics:
* NSAIDs
* Opioids (morphine)

Treatment by cause of pain itself
* Anti-spasmatic (if pain is caused by spasm of muscle at site of injury)
* Anti-acid
* Vasodilator (prevent ischemia)

Question 22

Electrical Treatment of Pain

Answer 22

• Stimulation of supraspinal descending analgesic system
• Stimulation of A beta fibers

Question 23

Surgical treatment of Pain

Answer 23

• Anterolateral cordoctomy: cutting off spinothalamic tract
• Prefrontal Lobectomy