Pain Flashcards
Define pain
Unpleasant sensory & emotional experience associated with actual or potential tissue damage
Describe the pain tracts
Spino (cervico) thalamic tract:
First order neurone synapses in dorsal horn of spinal cord
These synapse with second order neurons which cross over to ascend in spinothalamic tract
Third neurone arises in thalamus & ascends to cortex
Responsible for transmitting touch & superficial pain
Spinoreticular tract:
Deep pain & visceral sensations
Primary afferents enter spinal cord & spread over several segments to allow intersegmental reflexes such as withdrawal
Second order afferents in dorsal horn pass into thalamus to activate limbic system and cause emotional response
Poorly localised
What are some non conscious responses to pain
Cardiovascular changes
Respiratory changes
Behavioural changes
Increased adrenaline & glucocorticoids
What is nociception
Neural process of encoding noxious stimuli
Physiological process that results in perception of pain
Feeling only becomes pain when brain perceives & interprets it
What are the types of nociceptors
A is fastest fibre (myelinated) - sharp pain, localised
C is slowest fibre (unmyelinated) - dull aching pain, not well localised
What is a noxious stimulus
Stimulus that is damaging or threatens damage to normal tissues
What is somatic pain
Pain experienced from skin, muscle & bone damage/disease
What is visceral pain
Pain experienced because of organ pain
