What is a Sensory System?

Sensory systems are pathways in the nervous system that allows stimuli to be detected and perceived. They underlie the major senses of vision, hearing, smell, taste and touch, as well as temperature and pain. Additionally, some of them, such as the vestibular system, provide feedback about body position.

All sensory systems have receptors, specialized cells that detect a stimulus, such as the photoreceptors in the eye that detect light. The stimulus triggers changes in the receptor cell, such as altering electrical potential across the membrane, transducing it into a neural signal.

The signal is then transmitted across synapses through a series of neurons to the brain, either directly, as in the visual system, or through the spinal cord, as in the somatosensory system, which carries touch information from the skin.

While the exact pathways vary, most sensory information travels to the thalamus of the brain, and is then sent to regions of the cerebral cortex devoted to processing particular types of stimuli, for instance, visual, somatosensory or auditory information.

From here signals are sent to other areas of the cerebral cortex, allowing for integration of information and higher-level processing. Ultimately the analysis carried out by the nervous system leads to a conscious perception of the stimulus.