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22 terms

chapter 13 PNS

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sensory receptors
___ ___ are specialized to changes in their environment, which are called stimuli
mechanoreceptors
classification by stimulus type: these receptors respond to force such as pressure, vibration, touch, and stretch
thermoreceptors
classification by stimulus type: these receptors are sensitive to temperature changes
photoreceptors
classification by stimulus type: these receptors, such as those of the retina of the eye, respond to light energy
chemoreceptors
classification by stimulus type: these receptors respond to chemicals in solution (smells, tastes, changes in blood)
nociceptors
these receptors respond to potentially damaging stimuli that result in pain. this includes subtypes of thermo, mechano, and chemoreceptors
exteroceptors
these receptors are sensitive to stimuli arising outside the body and are located near the body surface. they sense touch, pressure, pain and temp on the skin and most special senses
interoceptors
these receptors, also called visceroceptors, respond to stimuli within the body. they can cause discomfort, thirst, and hunger, but we are usually unaware of hteir workings
proprioceptors
these receptors, like interoceptors, respond to internal stimuli, but their location is restricted to muscles, tendons, ligaments, joints, and tissue coverings. they monitor how much these things are stretched
simple
there are simple and complex receptors, but most are ___
sense organs
complex receptors are actually ___ ___, localized collections of cells associated with the special senses
general sensory
___ ___ receptors are involved in sensing touch, pressure, stretch, vibrations, and a bunch of other simple senses. they can be free nerve endings or encapsulated nerve endings
unencapsulated
these nerve endings, also called "free," are present nearly everywhere, but are abundant in the skin and connective tissue. they respond chiefly to painful and temp stimuli, includes merkel discs and hair follicle receptors
vanilloid receptor
a recently discovered receptor, the __ ___, in the plasma membrane of nociceptive free nerve endings, is an ion channel opened by heat, low pH, and capsaicin
Merkel discs
certain free nerve endings associate with enlarged disc shaped epidermal cells to form ___ ___, which lie in deep layers of the epidermis and function as light touch receptors
hair follicle receptors
____ ____ ___ are light touch receptors that detect bending of hairs
encapsulated dendritic endings
all ___ ___ ___ consist of one or more fiber terminals of sensory neurons enclosed in a connective tissue capsule. virtually all are mechanoreceptors
Meissner's corpuscles
encapsulated receptors known as ___ ___ are small exteroreceptors that respond to light pressure, discriminative touch, vibration of low frequency, and they rapidly adapt
pacinian corpuscles
these encapsulated dendritic receptors are extero, intero, and protioceptors that respond to deep pressure, stretch, vibration of high frequency, and are rapidly adapting
Ruffini endings
___ ___ are encapsulated receptors that lie in the dermis, subcutaneous tissue, and joint capsules that and exteroceptors and proprioceptors. they respond to deep pressure and stretch and don't really adapt
muscle spindles
___ ___ are proprioceptors found throughout the perimysium of skeletal muscles. they respond to muscle stretch and length and initiate a reflex that resists stretch
golgi tendon organs
___ ___ ___ are proprioceptors located in tendons, close to the skeletal muscle insertion. they consist of tendon fibers enclosed in a capsule with sensory terminals coiling between and around the fibers.