Analgesia

Question 1

What does enkephalin do?

Answer 1

Activates opoid receptor expressed by
- A delta and C fibres
- dorsal horn fibres
Inhibits DHN depolarisation by opening K+ channels fort K+ to move out and DHN hyperpolarised
Act presynaptically to inhibit the opening Ca2+ channels - reduced Ca2+ entry means less NT is released

Question 2

When does natural analgesia occur?

Answer 2

Relaxation - increas in encephalin and serotonin release centrally

Question 3

What stimulates encephalin release

Answer 3

Nerve stimulation

Question 4

What happens during rubbing

Answer 4

Inhibitory interneurons can be activated by A beta fibres

Question 5

What happens during HEat

Answer 5

Sooth stiff joints - increase blood flow and relax muscles

Question 6

how do opoids act

Answer 6

In the same way as encephalins

stimulate RMNs to activate interneurones

Question 7

What do NSAIDs do

Answer 7

Inhibit COX

decrease in prostoglandins and hyperalgesia

Question 8

How do local anathetics work?

Answer 8

Blocks initiation and propagation of the AP by pain fibres

binds to Na+ channels closing the inactivation gate no new ap transmitted

Question 9

When is local anaesthetics reduced?

Answer 9

presence of bacteria

Question 10

What do anti-depressants do?

Answer 10

Produce analgesia
increase serotonin levels in the synaptic cleft
Increase in activation of descending analgesic pathway