Skin Senses

4 Key excerpts on "Skin Senses"

• 

  eBook - ePub

  Sensation and Perception

  • Hugh J. Foley, Mary Bates(Authors)
  • 2019(Publication Date)
  • Routledge

    (Publisher)

  Chapter 12 The Skin Senses

  • The Skin
    • Receptors in the Skin
    • From the Skin to the Brain
  • Touch
    • Afferent Systems for Touch
    • Passive Touch
    • Active Touch
    • Interactions between Touch and Other Senses
  • Temperature
    • Afferent Systems for Temperature
    • Thresholds for Temperature
    • Adapting to Temperature
  • Pain
    • Afferent Systems for Pain and Gate-Control Theory
    • ● IN-DEPTH: Phantom Limbs and Pain
    • Measuring Pain
    • Adapting to Pain
    • Controlling Pain
  • Kinesthetic and Vestibular Senses
    • Kinesthetic Sense
    • Vestibular Sense

  In elementary school, your teacher might have told you about the five senses: vision, hearing, touch, smell, and taste. Aristotle used this classification system more than 2300 years ago, and it is probably still the most common one. However, it’s clear that we rely on more than five senses. In this chapter, we’ll explore a set of senses embedded in our bodies, collectively called the somatosensory system (from the Latin and Greek soma meaning “body”).

  The somatosensory system has three separate systems that interact with one another (Pinel, 2006 ). We’ll ignore one system, which monitors your body’s internal states. We’ll focus primarily on another system, which interprets the impact of the outside world on your body. This system provides you with touch, temperature perception, and pain perception. Finally, we’ll consider the system that informs you about whether you are standing upright or tilted and where your body parts are in relation to each other. That somatosensory system is augmented by information from the vestibular system of the inner ear, which we first mentioned in Chapter 9 .

  The Skin

  Your skin represents the largest sensory system you own, with a surface area of about 2 square yards in adults (Weisenberger, 2001

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  Workshops in Perception

  • R. P. Power, S. Hausfeld, A. Gorta(Authors)
  • 2017(Publication Date)
  • Routledge

    (Publisher)

  Skin and body senses        

  While it has been traditional to speak of the five senses (seeing, hearing, smelling, tasting and touching), the number of sensory systems we use is open to debate. The answer depends, in part, on whether the sensory systems are categorised in terms of the different receptors involved or in terms of the different stimuli to which they are sensitive. The position of both seeing and hearing is clear using either of these criteria; however, the position of touching is not as clear.

  One form of touching includes feeling the pile of a fabric. Here the skin may be considered the receptor. However, besides being sensitive to pressure, the skin is also sensitive to pain, warm and cold, but the nature of the particular receptors is not well understood. Another form of touching involves grasping an object to determine its shape or thickness. Here receptors in the muscles, joints or tendons may be involved in addition to those of the skin. Receptors in the muscles, joints and tendons are also important in the perception of movement and the perception of the position of the body and its parts (proprioception and kinesthesis). This in turn may be related to the vestibular system, with receptors in the ear, which is important to balance and hence to perception of posture and movement. Thus the overlap in both the receptors or the stimuli involved makes classification into a number of separate sensory systems very difficult. The workshops in this section range from investigations of sensory thresholds of the skin to bodily perception of the vertical.

  The staircase psychophysical method is used in Workshop 10 to determine the two-point touch threshold for different skin areas. Observations from over 120 years ago reveal that the sensitivity of the skin can be increased with training. Furthermore, the sensitivity of adjacent and symmetrical areas not receiving the training has also been found to increase. In Workshop 10, the effect of feedback on the two-point threshold is investigated in different skin areas. This also allows a simple demonstration of the fact that the skin is not equally sensitive on all parts of the body.

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  Medical Physics and Biomedical Engineering

  • B.H Brown, R.H Smallwood, D.C. Barber, P.V Lawford, D.R Hose(Authors)
  • 2017(Publication Date)
  • CRC Press

    (Publisher)

  Chapter 3

  Physics of the Senses

  3.1 Introduction and Objectives

  We might regard the body as a complex, elegant and sometimes incomprehensible computer. The central processor of this computer is the brain, and the primary connection to this CPU is the spinal cord. These components are called the central nervous system (CNS). The CNS receives data through a set of communication ports, processes it and sends instructions through another set of ports. Collectively these ports and their cabling are called the peripheral nervous system (PNS). The output devices control muscle activity through the autonomic and somatic nervous systems. The input devices monitor the performance of the body and keep the CNS aware of the external environment. In this chapter we shall focus on these external monitors, represented by the five senses. The importance of these senses to our general well-being cannot be overemphasized. Deprived of sensory input the brain is apt to invent its own: hallucinations of sight, sound and smell are reported by sane and normal volunteers under conditions of sensory deprivation.

  Our perception of the outside world depends on our five senses. There are many texts devoted to the study of the senses, and each sense represents a rich field of research in its own right. Damask (1981) devoted a volume of his medical physics text to the external senses, and this chapter draws on his text particularly for the senses of touch, taste and smell. Formally, the five senses are:

  Cutaneous sensation	Touch
  Gustation	Taste
  Olfaction	Smell
  Vision	Sight
  Audition	Hearing.

  The elements of the peripheral nervous system that respond directly to stimuli are called the sensory receptors. For the purposes of the present chapter a receptor is a transducer that produces electrical energy, in this case a nerve impulse, from the form of energy (mechanical, thermal, light) that it is designed to respond to. We shall focus on the physics of the route by which energy is presented to the receptor, and not on the subsequent electrical activity. The process of the initiation of the electrical impulse and the propagation of the signal are covered in more detail in Chapter 16

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  Touch in Museums

  Policy and Practice in Object Handling

  • Helen Chatterjee, Helen Chatterjee(Authors)
  • 2020(Publication Date)
  • Routledge

    (Publisher)

  Skin is a mam interface between an individual and the outside world. The sense of touch informs and guides close interactions with the immediate environment. The skin is also the largest organ in the body and is vital for controlling and maintaining the health of the body as a whole, a process known homoeostasis, to ensure the stability of the internal environment. Emotions arise from the demands of meeting inner bodily needs - for example, in hunger or thirst - and the skin is not left out of these emotional processes. Touch, as an exploratory sense, is complemented by parallel sensations intrinsic to the skin that have strong motivational meaning. Particular nerve fibres carry these allied sensations (including sensual touch, tickle, temperature and pain) to the brain. The fibres themselves are of the same type as the nerves that innervate and control the internal bodily organs. These visceral and skin sensations reach the brain by a different pathway to conventional, discriminatory, analytic touch. Within the brain, the information by-passes somatosensory cortex to access directly emotional regions that support emotional feeling states, guide and motivate behaviour and reinforce memories.

  The Hypnoglyph

  There is a short science fiction story that I recall reading at school entitled 'The Hypnoglyph' (Anthony 1953). I recently located an original copy of the anthology, and also learned that the author was John Anthony Ciardi, an American poet and academic, who wrote this science fiction piece in 1953 under the name John Anthony. The story involves a man visiting a friend who collects unusual alien artefacts, including a beautifully carved piece of wood. The owner calls it the prize of his collection and hands it over to his guest to feel and stroke. They chat about tactile pleasure and discuss a late twentieth-century artist and sculptor whose work focused on creating sensual touch experiences. Then the collector begins the story about how he acquired the carved object. He describes prospecting for crystals in deep space when his team discover a new planetary system that previously was thought merely to be an asteroid belt. On one of the planets there is intelligent primate-based life. There he retrieves the object that he says, surprisingly, was a hunting implement. He describes the human-like alien culture further:

  The women of the proper clan work these things and the men set them out in the forests ... the animals with their extremely high tactile suggestibility come through the forest and find one of these things in their way. They begin to stroke and feel it and they just can't stop. The men don't even kill them, all the slaughtering is done by the ruling clan of women. The men simply wait until the animal has worked itself into a right state then lead it back to the slaughtering compound. (Anthony 1953)

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