CNS test 2- Innervation of the skin Flashcards
small part of a dermatome where a sensory unit can be excited
receptive field
the entire neuron will cell body located in DRG
sensory unit
strip of skin innervated by a single spinal nerve
dermatome
Sensory transduction
tranformation of a stimulus into an electrical signal
phasic receptors, response quickly to and maximally at onset of stimulus, but stops responding even if the stimulus continueus
Rapidly Adapting receptors
essential in responding to changes (due to high sensitivity) but ignore ongoing processes such as wearing a watch
rapidly adapting receptors
tonic receptors that continue to responds as long as stimulus is present
slowly adapting receptors
close to body’s surface, detect sensory info from external environment (senses: touch, smell, sight etc)
Exteroreceptors
Transmit sensory info from muscle, tendons, and joints about the position of a body part, such as a limb in space
proprioceptors
direct sensory information about body’s internal environment (stretch/bp/pH/O2 etc)
interoceptors
nociceptors
rapidly adapting-noxious/painful stimuli
sensitive to temperature
thermoreceptors
detect physical deformation due to touch/stretch/pressure/vibration
mechanoreceptors
non-encapsulated mechanoreceptors
free nerve endings
follicular
merkel’s discs
free nerve endings
found close to surface, transmit pain and temperature, slow adapting
Peritrichial, coiled around hair follicles and respond when a hair is bent, touch, rapidly adapting
follicular receptors
tactile receptors, special epidermal cells with free nerve endings under them. discriminative touch stimuli allows for distinguishing texture, shape, and edges of objects (slow adapting)
Merkel’s discs
Encapsulated
Meissner’s corpuscles
pacinian corpuscle
Ruffini’s end organ
located in papilla of dermis, rapidly adapting for light touch/fine discrimination
meissner’s corpuscles
largest skin receptor, no magnification necessary located on the dermis, responds to pressure, tickling, and vibration, rapid adaptation
Pacinian corpuscles
Deeper pressure/shearing/drap slowly adapting
Ruffini’s end organs
slow adapting
Free nerve endings
Merkel’s discs
Ruffini’s end organs (encapulated)
fast adapting
Follicular (non encapsulated)
Meissner’s corpuscles
Pacinian corpuscles