Llemniscus emniscus lemniscal axons ascend without

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Unformatted text preview: l nucleus hey reach the ventral posterior llateral nucleus he posterior at (VPL) of the thalamus. (VPL) of the thalamus. (VPL) ((All sensory input to the brain, with the All (All sensory input to the brain, with the exception of olfactory, is processed in the exception of olfactory, is processed in the thalamus)) tthalamus halamus Axons arisiing in VPL ascend tto tthe cerebral Axons aris ng iin VPL ascend to the cerebral n ascend o he cortex in the postcentral gyrus ((Brodeman cortex in the postcentral gyrus Brodeman postcentral areas 1, 2,, 3, and 5), where 'local sign' of areas 1, 2 3, and 5), where ''local sign' of local areas ttouch sensation is recognized. ouch sensation is recognized. These two nuclear These two nuclear groups and their groups and their associated fasciculi can asciculi can associated ffasciculi can be seen as slight be seen as slight swellings on the dorsal swellings on the dorsal surface of the medulla. surface of the medulla. The bump formed by The bump formed by nucleus and fasciculus asciculus nucleus and ffasciculus gracilis iis called the gracilis is called the s gracile tubercle gracile tubercle and that caused by and that caused by nucleus and fasciculus asciculus nucleus and ffasciculus cuneatus iis called the cuneatus s called the cuneate ttubercle. cuneate tubercle. ubercle. Spinal Sensory Pathways Spinal Lateral Spinothalamic Tracts Lateral Spinothalamic Tracts Spinothalamic principal pathways pain, temperature, principal pathways pain, temperature, pressure, tickle, itch, and light or crude pressure, tickle, itch, and light or crude touch. ttouch. ouch. light touch-sensation produced by llight touch-sensation produced by sensation ight stroking hairless skin with a ffeather stroking hairless skin with a eather orr cotton wisp or cotton wisp o crude touch- llocation can only ocation crude touch- location can only crude vaguely identify vaguely identify Pain fibers are small and usually Pain fibers are small and usually unmyelinated, while thermal fibers unmyelinated while thermal fibers unmyelinated, while usually have myelin. usually have myelin. ffirst order neurons synapsis occurs in irst order neurons synapsis occurs in synapsis occurs the dorsal horn tthe dorsal horn he Postsynaptic (second order) neuron...
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This note was uploaded on 12/08/2011 for the course AMY 2A taught by Professor Jamesivey during the Spring '06 term at Riverside Community College.

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