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27 Cards in this Set
- Front
- Back
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special senses
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smell
taste vision hearing balance |
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general senses
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somatic senses
visceral senses |
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somatic senses
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tactile sensations
thermal sensations pain sensations proprioceptive sensations |
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tactile sensations
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touch
pressure vibration itch tickle |
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thermal sensations
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warm
cold |
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proprioceptive sensations
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joint & muscle position sense
movements of limbs & head |
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visceral senses
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provide information about conditions within internal organs
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sensation
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conscious or subconscious awareness of changes in external or internal environments
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for sensation to occur, must have:
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stimulus (light, heat, pressure, mechanical energy, chemical energy)
sensory receptor conduction of nerve impulses integration of nerve impulses |
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perception
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conscious awareness/interpretation of sensations
primarily a function of cerebral cortex |
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adaptation
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decrease in strength of sensation during prolonged stimulus
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sensory receptors grouped by:
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structure
function |
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STRUCTURAL classification of sensory receptors:
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free nerve endings
encapsulated nerve endings separate cells |
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FUNCTIONAL classification of sensory receptors:
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MECHANORECEPTORS
---pressure THERMORECEPTORS ---temperature NOCICEPTORS ---pain PHOTORECEPTORS ---light CHEMORECEPTORS ---chemicals in mouth (taste), nose (smell), and body fluids OSMORECEPTORS ---osmotic pressure of body fluid |
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free nerve endings
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bare dendrites
associated with: pain, thermal, tickle, itch, and some touch |
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encapsulated nerve endings
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dendrites enclosed in connective tissue capsule
ex: corpuscle of touch |
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separate cells
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receptor cell synapses with sensory neuron
located in: retina (photoreceptors) inner ear (hair cells) taste buds (gustatory receptors) |
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tactile receptors of the skin or subcutaneous layer
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*FREE NERVE ENDINGS
---itch and tickle *CORPUSCLES OF TOUCH *HAIR ROOT PLEXUSES *TYPE I AND II CUTANEOUS MECHANORECEPTORS *LAMELLATED CORPUSCLES ---touch, pressure, vibration |
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TOUCH
corpuscles of touch |
aka: meissner corpuscles
located in hairless skin egg-shaped encapsulated nerve endings |
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TOUCH
hair root plexuses |
free nerve ending wrapped around hair follicles of hairy skin
detect movement on skin surface that disturbs hairs |
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TOUCH
type I cutaneous mechanoreceptors |
aka: merkel discs
saucer shaped, free nerve endings make contact w/ merkel cells in stratum basale fingertips, hands, lips, external genitalia |
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TOUCH
type II cutaneous mechanoreptors |
aka: ruffini corpuscles
elongated, ecapsulated receptors located deep in dermis, in ligaments and tendons hands, soles of feet *most sensitive to stretching of digits or limbs |
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pressure
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sustained sensation, felt over larger area than touch
involved receptors: -corpuscles of touch -type I mechanoreceptors -lamellated corpuscles |
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lamellated corpuscles
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large, oval, multilayered
adapt rapidly widely distributed in body: dermis, subcutaneous layer, joints, tendons, muscles, periosteum, mammary glands, external genitalia, pancreas, urinary bladder |
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vibration
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rapidly repetive sensory signals from tactile receptors
-corpuscles of touch: lower frequency vibration -lamellated corpuscles: higher frequency vibration |
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itch
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stimulation of free nerve endings
often result of local inflammatory response |
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tickle
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stimulation of free nerve endings and lamellated corpuscles
can only occur when someone else touches you, not when you touch yourself |
