The 'somatosensory system' is a sensory system that detects experiences labelled as touch or pressure, temperature (warm or cold), pain (including itch and tickle) and those that belong to proprioception. These are the sensations of muscle movement and joint position including posture, movement, visceral (internal) senses and facial expression. Visceral senses have to do with sensory information from within the body, such as stomach aches.