How Do We Sense Movement and Motion?
The Sense of Movement
Kinesthetic Sense, or the sense of movement, provides information about the body's movement, posture and orientation. Kinesthetic sensory receptors are embedded in muscle fibers and joints, and the neural pathway is the same with the cutaneous sense for pressure, where kinesthetic sensory information goes to the spinal cord, the brain stem, the thalamus, and finally, to the somatosensory areas in the frontal and parietal lobes. To illustrate how the kinesthetic sense works, consider how a typist memorizes the keys of a typewriter machine and finally learns to type without looking.
The Sense of Motion
Vestibular Sense, or the sense of motion, on the other hand, provides information about movement in the external environment. Vestibular sensory receptors are hair cells located at vestibular sacs found inside the semi-circular canals of the auditory system. Because these canals are filled with fluid, hair cells react to gravity to give information about the body's plane of movement - right/left, forward/backward, and upward/downward. Vestibular sensory information is then transmitted by the auditory nerve, particularly the vestibular nerve, to the brain. Most information goes to the medulla, although some arrive in the cerebellum and the temporal lobes. Neural pathway in the medulla is the primary reason for experiencing nausea during motion sickness, while dizziness is attributed to the path to the temporal lobes.
The kinesthetic and vestibular senses work hand-in-hand, together with the rest of the body's senses, especially the visual system, to provide information about the movement and position of the different parts of the body in relation to each other and the immediate environment. Proprioceptive Feedback is the mechanism in which the different types of sensory information are checked for consistency and continuity.