Fibers the remaining part of touch, pain, heat and cold synapse with the cells in the posterior horn of the spinal cord soon after entry. The second order neurons arising from these cross to the opposite side at different levels (pain and temperature fibers more obliquely one or two segments above) and pass up on the other side as the (touch) and lateral tract (pain and temperature). In the lateral tract fibers from the lower limbs are placed laterally and fibers from the upper limbs are medial. Some fibers do not cross and they pass up http://publishvaultreviews.com/
tracts. In the tracts pass up lateral to the medial to reach the thalamus. Third order neurons arise from the thalamus. Third order neurons arise from the thalamus and fibers which maintain their functional specificity pass up through the internal capsule to be relayed to the sensory area of the int he
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