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==Pain==
 
==Pain==
*"Painful stimuli" can range from itches, to nausea, to being in agony.
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Painful stimuli can result in responses ranging from itches, to nausea, to simply being in agony. Painful stimuli may be transmitted to the brain by one of two pathways: the [[Sensory Pathways - Anatomy & Physiology#Spinothalamic Tract|Spinothalamic Tract]] or the the [[Sensory Pathways - Anatomy & Physiology#Ascending Reticular Formation|Ascending Reticular Formation]].
*Painful stimuli may be transmitted to the brain by one of two pathways:
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::[[Sensory Pathways - Anatomy & Physiology#Spinothalamic Tract|Spinothalamic Tract]]
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::[[Sensory Pathways - Anatomy & Physiology#Ascending Reticular Formation|Ascending Reticular Formation]]
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'''Spinothalamic Tract'''
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===Spinothalamic Tract===
*Fast, initial pinprick is detected by free [[PNS Structure - Anatomy & Physiology#Nerve Fibres|nerve]] endings
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This fast, initial pinprick is detected by free [[PNS Structure - Anatomy & Physiology#Nerve Fibres|nerve]] endings and causes an impulse along large, myelinated fibres. The pain sensation is localised, and ends quickly.
*Causes an impulse along large, myelinated fibres
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*Pain sensation is localised, and ends quickly
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'''Ascending Reticular Formation'''
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===Ascending Reticular Formation===
*A painful sensation is detected by free [[PNS Structure - Anatomy & Physiology#Nerve Fibres|nerve]] endings
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This pain sensation is detected by free [[PNS Structure - Anatomy & Physiology#Nerve Fibres|nerve]] endings which causes an impulse along small, unmyelinated fibres. This results in a delayed perception of the sensation of pain, and that pain is often less localised but more persistent.
*Causes an impulse along small, unmyelinated fibres
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*A delayed sensation of pain is percieved, that is less localised, persistent.
      
'''Clinical Relevance'''
 
'''Clinical Relevance'''
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