The perception of pain and its threshold are the result of complex interactions between sensory, emotional and behavioural factors. Inflammation and nerve injury can reduce pain thresholds and increase sensitivity to sensory stimuli (Hudspith et al, 2005).
Acute pain is frequently caused by tissue damage and resultant inflammatory reactions causes' local release of mediators such as prostagladines, histamine, bradykinin, substance P and noradrenaline (Williams and Asquith, 2000). In conditions where excitation of pain fibres become greater as the pain stimulus continues, hyperalgesia develops which is an extreme sensitivity to pain and in one form is caused by damaged to nociceptors in the bodies soft tissues ( Wikipedia, 2006).
Pain receptor or nociceptors are naked ending of A and C nerve fibres through which the body is able to detect the occurrence, location, intensity and duration of noxious stimuli that stimulates pain sensation (Dalgleish, 2000). Fast pain is meditated by A nerve fibres which are felt within a tenth of a second of the application of the pain stimulus which can be described as sharp and acute pain. Slow pain meditated by type C nerve fibres is an aching throbbing and burning pain (Wikipedia, 2006). ...Show more