Touch TOUCH Position, Movement, and the Skin Senses

Essential Questions How does the brain translate touch? What are the differences in the vestibular, kinesthetic and cutaneous sense? What are some common sensory disorders related to touch and skin senses?

Cutaneous Sense (Skin Senses) What is it? receptors that lie just below the surface of the skin o respond to touch, pressure, and temperature to varying degrees based on part of body affected How does it work? connected to somato sensory cortex in the brain's parietal lobe information transmitted from receptors to nerve fibers routed through spinal cord to brainstem o adaptations can then be made or conditions are tolerated Ex: person's ability to feel pain

How does it work? substance P used as a neurtransmitter endorphins increase in concentration when body responds 2 types of pathways information is sent to the brain by the thalamus 1.Fast parthway (myelinated): detects localized pain and sends info rapidly to cortex 2.Slow pathway (unmyelinated): carries less- localized, longer- acting pain info not merely the result of stimulation (ex: phantom limb) yet to develop a theory that explains everything about pain

What is Pain? Defined: part of body's adaptive mechanism o in response to conditions that threaten damage to the body o alert that something is wrong level of pain varies depending on a person's tolerance/ threshold o perception of brain

Sensory Receptors 100 touch receptors in each fingertip Cutaneous Receptors: Located in dermis or epidermis o Cutaneous Recepors o Thermoreceptors (temperature) o Nocioreceptors (pain)

Sensory Receptors Continued Mechanoreceptors o Receptors of mechanical stimuli o Initiates nerve impulses in sensory neurons when it is physically deformed by an outside force like:  Touch, pressure, stretching, sound waves, motion o Enable us to:  Detect touch, changes in pressure, position, acceleration  Detect sounds and the motion of the body  Monitor the position of our muscles, bones, and joints- sense of proprioception

Specialized neurons which are sensitive and detect hot or cold temperatures Useful in alerting organisms od possible danger and changes in environmental conditions so they can react Provide brain with information about environmental temperature o Alerts brain to cool or heat body accordingly Thermoreceptors

Free nerve endings that exist in all body tissues Responsible for sending messages of pain o caused by unpleasant response by a combination of tissues damage and emotional reaction o Sensations are warning messages Messages travel through afferent nerve tracts to the spinal cord Nocioreceptors

Practical Uses Lamaze method o developed by French obstetrician Fernand Lamaze o by work of psychologist Ivan Pavlov  practical use of "conditioning" o uses breathing and concentration techniques to help women during birth Acupuncture procedure developed by the Chinese for controlling pain method done by insertion of long needles in various parts of the body One theory suggests that needles activate large nerve fibers and close the pain gate, other believe it releases endorphins

Theories relating to Touch Control Theory: (1965) o Melzack and Wall o Represents balance in neural activity of cell o Receives information from body and sends to brain o Pain signals pass through "gate" in spinal cord o Can be closed by nonpain signals coming into the spinal cord & by signals coming from brain Control Theory: (1965) o William Glasser o Also known as Choice Theory o implies active role, or responsibility towards ones behavior o all behavior is made up of three components: what we do, what we think, and what we feel o all behavior is an attempt to satisfy powerful forces within ourselves o regardless of our circumstances, all we do, think, and feel, is always or best attempted at the time to satisfy the forces within us

Vestibular Sense What is it? sense of body orientation with respect to gravity o person's fit in the environment o oriented in space and time shows us how we are moving and how our motion is changing o awareness of body balance and movement How does it work? closely associated with the inner ear information is carried to the brain on a branch of the auditory nerve Ex: body posture- straight, leaning, reclining, upside down..

Continued Inner ear portion of ear located within temporal bone that is involved in hearing and balance o includes the semicircular canals, vestibule, and cochlea o sound vibrations transmitted from cochlea to the brain by the auditory nerves Semicircular canals Located in inner ear o Movement of fluid in canals stimulates hair cells, located on the basilar membrane, which sends messages to the brain about speed and direction of body rotation Important for balance Utricle Membranous sac contained within the labyrinth of the inner ear Connected with the semicircular canals

Kinesthetic Sense What is it? movement of the body's muscles, tendons, and joints helps us move with greater precision, avoid injuries, and be fully present in the moment ability to sense body position How does it work? proprioceptors send messages to the brain and works with sensory input to formulate feelings Ex: person playing soccer Tober

Disorders Phantom limb sensation o Occur to people that were born without a limb or have had a limb amputated o pain that comes from missing part o arise in the brain o mNlPdHQ mNlPdHQ Tactile Sensory Dysfunction o often found in children who are bothered or fearful to touch things. o examples:  certain clothing textures, seams and/or materials  A hug  Bare feet touching grass or sand

Works Cited Boeree, George C. "The Senses: A Whirlwind Tour." General Psychology. webspace.ship.edu, Web. 30 Nov Brown,. Mistaken for ADHD blog. N.p., n.d. Web. 1 Dec Brown, David. "The Vestibular Sense." N.p., June Web. 30 Nov Ciccarelli, Saundra K., and Glenn E. Meyer. Psychology: mypsychlab edition. Upper Saddle River, NJ: Pearson Prentice Hall, "Touch the skin receptors." Think Quest. N.p., n.d. Web. 1 Dec