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| *Ascending tracts cross over the midline of the body to the contralateral side of the [[Forebrain - Anatomy & Physiology#Thalamus|thalamus]]. | | *Ascending tracts cross over the midline of the body to the contralateral side of the [[Forebrain - Anatomy & Physiology#Thalamus|thalamus]]. |
| *The [[Forebrain - Anatomy & Physiology#Thalamus|thalamus]] directs the signal to the [[Forebrain - Anatomy & Physiology#Cerebral Cortex|cerebral cortex]] for conscious perception. | | *The [[Forebrain - Anatomy & Physiology#Thalamus|thalamus]] directs the signal to the [[Forebrain - Anatomy & Physiology#Cerebral Cortex|cerebral cortex]] for conscious perception. |
− | **The pathway is direct, with very few [[Nervous System - PNS - Anatomy & Physiology#Nerve Fibre|neurones]] involved. | + | **The pathway is direct, with very few [[PNS Structure - Anatomy & Physiology#Nerve Fibre|neurones]] involved. |
| | | |
| ====1. Dorsal Columns==== | | ====1. Dorsal Columns==== |
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| *True pain sensation; pain lasts longer. | | *True pain sensation; pain lasts longer. |
| *Sensory information enters the [[Spinal Column - Anatomy & Physiology|spinal cord]] on the ipsilateral side of the stimulus. Some signals cross to the contralateral side of the body. | | *Sensory information enters the [[Spinal Column - Anatomy & Physiology|spinal cord]] on the ipsilateral side of the stimulus. Some signals cross to the contralateral side of the body. |
− | *The tract consists of '''several''' [[Nervous System - PNS - Anatomy & Physiology#Nerve Fibre|short neurones]]. | + | *The tract consists of '''several''' [[PNS Structure - Anatomy & Physiology#Nerve Fibre|short neurones]]. |
| *Therfore the ascending reticular formation is ''bilateral'' and ''multineuronal''. | | *Therfore the ascending reticular formation is ''bilateral'' and ''multineuronal''. |
| *This pain pathway is more primitive than the [[Sensory Pathways - Anatomy & Physiology#Spinothalamic Tract|spinothalmic tract]]. | | *This pain pathway is more primitive than the [[Sensory Pathways - Anatomy & Physiology#Spinothalamic Tract|spinothalmic tract]]. |
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| '''Spinothalamic Tract''' | | '''Spinothalamic Tract''' |
− | *Fast, initial pinprick is detected by free [[Nervous System - PNS - Anatomy & Physiology#Nerve Fibres|nerve]] endings | + | *Fast, initial pinprick is detected by free [[PNS Structure - Anatomy & Physiology#Nerve Fibres|nerve]] endings |
| *Causes an impulse along large, myelinated fibres | | *Causes an impulse along large, myelinated fibres |
| *Pain sensation is localised, and ends quickly | | *Pain sensation is localised, and ends quickly |
| | | |
| '''Ascending Reticular Formation''' | | '''Ascending Reticular Formation''' |
− | *A painful sensation is detected by free [[Nervous System - PNS - Anatomy & Physiology#Nerve Fibres|nerve]] endings | + | *A painful sensation is detected by free [[PNS Structure - Anatomy & Physiology#Nerve Fibres|nerve]] endings |
| *Causes an impulse along small, unmyelinated fibres | | *Causes an impulse along small, unmyelinated fibres |
| *A delayed sensation of pain is percieved, that is less localised, persistent. | | *A delayed sensation of pain is percieved, that is less localised, persistent. |