General Sensory System and Taste

The sensory system is a complex system, whose function is to receive external stimuli and to process and integrate them with other functions superior to the level of the central nervous system. There are different types of sensory stimuli, mainly classified into proprioception, interoception, taste, touch, nociception, and thermoception. Regardless of the type of sensory stimulus, the system is made up of peripheral receptors, connection pathways, and processing and association centers at the cortical level. While taste information are conveyed to the CNS exclusively through cranial nerves, the other types of sensory stimuli, perceived through different kind of receptors located all over the body, are conveyed both through the dorsal columns of the spinal cord and cranial nerves. More specifically, dorsal horns of the spinal cord are composed by different layers, each one of them with a different cytoarchitecture and every type of sensory stimulus is directed to a different layer. Once the sensory information reaches the CNS, it is directed toward specific sensory cortices that are responsible for elaborating the stimuli and providing association pathways to other areas. In fact, the integration of sensory information is fundamental for completing fine and gross motor task, maintaining homeostasis and balance, correcting posture, and regulating the activity of the autonomic nervous system. Indeed, peripheral or central lesions of the sensory system can lead to conditions that could impair regular activity and, in some cases, cause severe consequences not only for the quality of life but also for the survival of the individual as well.