Summarizing Sensory Processes

Summary

A sensory activation occurs when a physical or chemical stimulus is processed into a neural signal (sensory transduction) by a sensory receptor. Perception is an individual interpretation of a sensation and is a brain function. Humans have special senses: olfaction, gustation, equilibrium, and hearing, plus the general senses of somatosensation.

Sensory receptors are either specialized cells associated with sensory neurons or the specialized ends of sensory neurons that are a part of the peripheral nervous system, and they are used to receive information about the environment (internal or external). Each sensory receptor is modified for the type of stimulus it detects. For example, neither gustatory receptors nor auditory receptors are sensitive to light. Each sensory receptor is responsive to stimuli within a specific region in space, which is known as that receptor’s receptive field. The most fundamental function of a sensory system is the translation of a sensory signal to an electrical signal in the nervous system.

All sensory signals, except those from the olfactory system, enter the central nervous system and are routed to the thalamus. When the sensory signal exits the thalamus, it is conducted to the specific area of the cortex dedicated to processing that particular sense.

Glossary

kinesthesia

sense of body movement

mechanoreceptor

sensory receptor modified to respond to mechanical disturbance such as being bent, touch, pressure, motion, and sound

perception

individual interpretation of a sensation; a brain function

proprioception

sense of limb position; used to track kinesthesia

reception

receipt of a signal (such as light or sound) by sensory receptors

receptive field

region in space in which a stimulus can activate a given sensory receptor

receptor potential

membrane potential in a sensory receptor in response to detection of a stimulus

sensory receptor

specialized neuron or other cells associated with a neuron that is modified to receive specific sensory input

sensory transduction

conversion of a sensory stimulus into electrical energy in the nervous system by a change in the membrane potential

vestibular sense

sense of spatial orientation and balance