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NEUROPHYSIOLOGY

Sensory Pathways: I

Spinothałamic iract

lower part of medulla nblongata

Latetal

spinothałamic tract; pain, temperaturę

Cerebral cortex: postcentral gyrus

Ventral posterolateral (VPL) nucleus of Ihalamus

Fasciculus gracilis

Dorsal (posterior) spinał root ganglion

Lumbui parł of spinał cord

Ccrvical part of spinał cord

limb ot intemal capsule

Large

Touch, \ "^^inMcd

Vontral tanterior) spinothałamic tract: louch, pressure

Smali

Pain,    1 myelinated

temperaturo j and unmyelin-ated fibers

Lateral cervicai nucleus Spinocervical tract

Figurę 2.29 Somesthetic System of the Body_

Pain, temperaturo, and pressure sensations below the head ulti-mately are conveyed to the primary somatosensory cortex ipostcen trał gyrus) by the anterolatcral system tspinothalamic and spinoretic-ulur trat ts). The fasciculus gracilis and cuneatus ol the spinał lemnisca! system convey proprioceplive, vibratory, and tactile sensa-tions to the thalamus <ventral posteroiateral nucleus), whereas the lateral ccrvical system mediates some touch, vibratory, and proprio-ceptive sensations (blue and purple lines show these dual pathways). Ultimately. these filjeis ascend as parallel pathways to the thalamus, synapsę, and ascend to the cortex.

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