10 Our skin contains more than four million sensory receptors. It is our biggest organ. Exposure to sounds higher than 110 decibels, even for a short time, can cause instantaneous and permanent hearing loss. flavour: sapore taste bud: papilla gustativa to trigger: scatenare 28 BODY AND MIND THE SENSORY SYSTEMS The sensory systems receive and process information that generates an individual s awareness of the external environment. Our senses can be grouped into three areas: exteroception, sensations from outside the body collected via the five senses of touch, sight, hearing, smell, and taste; proprioception, sensations about body position and movement; interoception, sensations from inside the body. The exteroceptive system The exteroceptive system includes: the tactile system, which processes touch information (like pressure, temperature, and pain) through receptors in the skin . It consists of two levels: the first informs the brain about where the touch is on the body, and the second says whether it is a safe or dangerous touch; the visual system, which is responsible for seeing. It recognises shapes, colours, letters, words, and numbers, and reads body language and other non-verbal clues during social interactions. Vision also guides our movements; the auditory system, which is used to identify the quality and direction of sound , and is involved in understanding language; the olfactory system, which processes smell, and which is one of the oldest and most vital parts of our brain. It is closely linked to the gustatory system, with which it works as an integrated system; the gustatory system, which deals with flavours and allows us to discriminate between safe and harmful foods. Taste buds are small sensory organs located in the tongue responsible for experiencing tastes. There are five basic tastes: sweetness, when there is the presence of sugar; sourness, when there is some form of acidity; saltiness, when salt is present; bitterness, when it contains ingredients which may be perceived as unpleasant, sharp, or disagreeable; umami, when the prevalent flavour is savouriness. The proprioceptive system The proprioceptive system senses the position, location, orientation, and movement of the body muscles and joints, enabling the brain to know where each body part is and how it is moving. It also includes the vestibular system (located in the ear), which contributes to balance and body orientation in space. It works with other systems to give our brain information about movement and position of head relative to gravity. It is also involved in the development of coordination, eye control, attention, and even some aspects of language development. The interoceptive system The interoceptive system collects the sensations related to the physical and physiological condition of the body, triggering responses that guide, for example, hunger, heart rate, and respiration. It is linked to our perceptions of well-being, energy, and stress.