where is the cell body for the axon that is carrying the sensory information into the spinal cord
Afferent nerve fiber Afferent neurons' somas are located in the ganglia of the peripheral nervous system, and the axons of these cells travel from ganglion to ganglion and lead back to the spinal cord. The majority of these are unipolar neurons in that they have a single axon leaving the cell body and is sent towards the sensory organ.[5] All of the axons in the dorsal root, which contains afferent nerve fibers, are used in the transduction of somatosensory information. Somatosensory receptors include senses such as pain, touch, temperature, itch, and stretch. For example, a specific muscle fiber called an intrafusal muscle fiber is a type of afferent neuron that lies parallel to the extrafusal muscle fibers thus functions as a stretch receptor by detecting muscle length.[5] All of these sensations travel along the same general pathway towards the brain, from the dorsal root ganglion they travel to the spinal cord.[5] From the spinal cord to the medulla, which then leads to the medial lemniscus of the midbrain. From here it travels to the primary somatosensory cortex of the parietal lobe.
Central nervous system This differentiates the central nervous system from the peripheral nervous system, which consists of neurons, axons and Schwann cells. Oligodendrocytes and Schwann cells have similar functions in the central and peripheral nervous system respectively. Both act to add myelin sheaths to the axons, which acts as a form of insulation allowing for better and faster proliferation of electrical signals along the nerves. Axons in the central nervous system are often very short (barely a few millimeters) and do not need the same degree of isolation as peripheral nerves do. Some peripheral nerves can be over 1m in length, such as the nerves to the big toe. To ensure signals move at sufficient speed, myelination is needed.