Pain Physiology Flashcards
What are the three classifications of pain?
Nociceptive
Inflammatory
Pathological
Which forms of pain are adaptive and maladaptive?
Pathological - maladaptive
Inflammatory - adaptive
Nociceptive - adaptive
What is a nociceptor?
A peripheral primary sensory afferent neurone activated by intense noxious stimuli
Why is pain essential for protection?
As it lets the body know something has gone wrong
What are the subtypes of nociceptor?
A delta fibres
C fibres
Which fibres are involved in first and second pain?
First pain - A delta fibres
Second pain - C fibres
Describe first and second pain
First - stabbing and pricking
Second - throbbing and cramping
Describe the nociceptive pathway
Free nerve ending stimulated which stimulates an action potential that simulates an axon of nociceptor (first order neuron) which stimulates a second order neuron causing pain
What are the afferent and efferent functions of C-fibres?
Afferent - transmits nociceptive information to CNS
Efferent - releases pro-inflammatory mediators causing neurogenic inflammation
Outline neurogenic inflammation
Peptides are released from free nerve endings causing vasodilation and release of histamine. Histamine sensitises surrounding nociceptors causing pain
What is primary hyperalgesia?
Pain sensitivity in surrounding tissues
What is secondary hyperalgesia?
Pain sensitivity in undamaged tissues
What is allodynia?
Pain sensitisation caused by non-painful repeated stimulation
