Pain Pharmacology and Analgesia

Question 1

What is pain?

Answer 1

An unpleasant sensory and emotional experience
associated with actual or potential tissue damage
or described in terms of such damage

Question 2

What are the two main pain pathways?

Answer 2

Pain is general associated with tissue damage, but there are two components
that are generally involved in pain states.

 The peripheral nociceptive afferent neuron which is activated by a noxious stimuli (damage to tissue)

 The central mechanism by which the affective input generates a pain sensation

Question 3

Stages of pain perception?

Answer 3

First stage is pain sensitivity

Second stage where the signals are transmitted
from the periphery to the dorsal horn (DH), which
is located in the spinal cord via the peripheral
nervous system (PNS)

Third stage is to perform the transmission of the
signals to the higher brain via the central nervous
system (CNS).

*see diagrams

Question 4

Brief description of neurotransmitter in relation to pain and synapses

Answer 4

1 - Action Potential reaches axon terminal
2 - Voltage gated calcium channels open and CA2+ enters cell
3 - Calcium triggers release of pain neurotransmitters into synapse
4 - Neurotransmitter binds to receptor post-synapse causing ion channels to open
5 - Depolarization continues

*see diagrams