Touch and pain signals are transmitted through the somatosensory system from the first-ordered afferent neuron to the somatosensory cortex. The first-order neuron is a pseudounipolar neuron. Its cell body is located in a peripheral ganglion. A peripheral branch of the axon forms somatosensory receptors, while another branch of the axon forms synapses with the second-order afferent neuron located in a spinal cord or nucleus of a brain stem. This neuron interacts with the third-order neurons located in the spinal cord or the thalamus. The thalamic neurons send their axons in the posterior limb of the internal capsule and form projections in the cerebral somatosensory cortex.