PHGY 209 Lecture Notes - Lecture 13: Posterior Grey Column, Optic Chiasm, Dorsal Root Of Spinal Nerve

• School: McGill University
• Department: Physiology
• Course: PHGY 209
• Professor: Anne Weschler

Document Summary

This branches into reticular formation in brain stem, and then go to thamalus and somatosensory cortex. If you lesion the anterolateral columns, the loss is temp and pain on the lateral side, but the loss of feelings below too! If you snip the dorsal root, you lose temp and pain on the ipsilaterlal side in addition to losing touch and proprioception. Somatotopic map corresponds to the number of affernts coming from each part of the body. Your back which is larger has less afferents coming from it, so it corresponds to a small segment. Highest acuity is in hand, then lips and face. Low acuity corresponds to fewer afferents, which is large receptive fields! Laterally on cortext is head, then arms, then legs. If you lesion the lateral part, you lose every feel on contralateral part: referred pain- visceral and somatic pain afferents commonly synapse on the same neuron in the spinal cord.