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12 Cards in this Set
- Front
- Back
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the large fiber pathway for tactile discrimination from the head overview |
aka trigeminal large primary afferents -function: detect fine touch, two-pt discrimination, proprioception from mechanoreceptors -uses A-beta and A-delta fibers in the trigeminal -3 neurons |
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the large fiber pathway for tactile discrimination from the head neuron 1 |
-origin: mechanoreceptors on A-beta and A-delta fibers from the trigeminal ganglion -course: trigeminal nerve - uncrossed -termination: principal sensory nucleus of trigeminal in the pons near nerve entry -organization: trigeminal distribution is topographically organized into ophthalmic, maxillary, and mandibular divisions |
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the large fiber pathway for tactile discrimination from the head neuron 2 |
aka trigeminal lemniscus -origin: principal sensory nucleus of trigeminal -course: axons form the trigeminal lemniscus that runs near the medial lemniscus-crossed -termination: ventrobasal complex of the dorsal thalamus, specifically the VPM nucleus -organization: the crossed tigeminothalamic tract carries info from all divisions, the ipsilateral tract is uncrissed and mostly carries info from the V3 division (oral cavity is represented bilaterally) |
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the large fiber pathway for tactile discrimination from the head neuron 3 |
aka thalamocortical projections of the VPM -origin: VPM -course: posterior limb of the internal capsule - uncrossed -termination: primary somatosenstory cortex areas 1, 2, and 3 -organization: in cortex, head and face is lateral and ventral in S1 |
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the small fiber trigeminal afferent pathway for pain and temperature sensation in the head overview |
-funct: pain and temperature sensation -3 neurons -noiceptors and mechano/thermo-receptors |
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the small fiber trigeminal afferent pathway for pain and temperature sensation in the head neuron 1 |
-origin: nociceptors, A-delta and C fibers from the small trigeminal ganglion cells; some cells from superior ganglion of glossopharyngeal and vagus nerves -course: trigeminal nerve - uncrossed -termination: spinal trigeminal nucleus (in pons, medulla, and upper cervical spinal cord) -organization: large receptive fields; concentric circles centered on the oral cavity: most caudal fibers represent the top of the head, most rostral are closest to oral cavity |
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the small fiber trigeminal afferent pathway for pain and temperature sensation in the head neuron 2 |
aka trigemino-thalamic pain pathway -origin: spinal trigeminal nucleus -course: trigeminothalamic tract - axons join the trigeminal meniscus near medial lemniscus - crossed -termination: VPM in thalamus -organization: oral cavity = medial; ophtalamic = lateral |
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the small fiber trigeminal afferent pathway for pain and temperature sensation in the head neuron 3 |
aka thalamocortical projections of the VPM assume same as the rest of the body -origin: VPM -course: internal capsule, posterior limb -termination: ambiguous modality neurons --> S1 cortex; specific pain info --> dorsal insular cortex; affect of pain info --> cingulate cortex |
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cornial blink reflex |
-spinal trigeminal ganglion small afferents innervate cornea -neurons from the spinal trigeminal nucleus have axons that branch and synapse in many places, including facial nucleus -post synaptic facial motorneurons fine and close the eyelid |
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mesencephalic trigeminal afferents overview |
aka motor trigeminal afferent -funct: jaw jerk reflex, proprioception info to principle sensory nucleus -2 neurons |
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mesencephalic trigeminal afferents neuron 1 |
-origin: muscle spindles and golgi tendon organs from Ia and Ib fibers enter the pons and continue rostrally to midbrain where the cell bodies are (in the mesencephalic trigeminal ganglion) -course: then continue caudally back to the pons - uncrossed -termination: motor nucleus of the trigeminal and principle sensory nucleus of the trigeminal -organization: by muscle group |
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mesencephalic trigeminal afferents neuron 2 |
-origin: motor neurons of the trigeminal nucleus -course: trigeminal nerve - uncrossed -termination: muscles of mastication, striated muscle -organization: by muscle group |
