Afferent neurons, also known as sensory neurons, carry sensory information to the central nervous system, or CNS. These neurons interact with efferent and interneurons to produce reactions based on sensations. The majority of afferent neurons in the body's peripheries are unipolar.
Afferent neurons are responsible for transmitting sensory information, including touch, sight, taste and smell. They usually have a unipolar structure, which includes dendrites at one end, followed by the axon and a presynaptic terminal that precedes the synapse. While the dendrites receive sensory information, axons pass them on to other neurons. Information in the form of an electrical impulse then travels down the neuron's axon, crosses the synapse and stimulates the interneuron with neurotransmitters. Most interneurons are located in the CNS. From there, the signal travels through the CNS and generates a response via the efferent neurons. For example, if the skin on someone's hand comes close to a fire, the pain travels along an afferent neuron, which transmits the information needed to make them withdraw their hand.
Most sensations from afferent neurons travel along the same pathway. After moving through the spinal cord, they reach the medulla and then the medial leminscus. After that, they reach the somatosensory cortex, which is located in the parietal lobe.