Peripheral sensory mechanisms Flashcards
what is glabrous skin? where is it found?
hairless: hands and feet with skin ridges
which corpuscles are close to surface?
Meissner corpuscles
Merkel complex
which corpuscles are deeper?
pascinian
Ruffini
Mechanoreceptors are?
the 4 corpuscles help to experience touch
how does transduction in a mechanosensory afferent work?
the ion channels are opened if threshold is reached via mechanical force eg. pascinian corpuscles and vibration
difference between slowly and rapidly adapting mechanoreceptors?
rapid: get used to stim easily and stops firing
slow: keeps firing, you’re aware after continued stim
tactile vs. nociceptive thresholds?
tactile: low threshold
nociceptor: high threshold/wide range
Which corpuscles have large vs. small receptor fields
large: pascinian, ruffini
small: meissner, merkel
Which corpuscles are slowly adapting?
merkel
ruffini
Which corpuscles are rapid adapting?
meissner
pascinian
Ruffini detect what?
proprioceptive
Pascinian detect?
vibrations
Merkel
indentation
Meisner detect?
light touch
which corpuscles has smallest receptor fields?
merkel
gripping an object: what do each of the 4 mechanoreceptors do?
Meissner encode rate of force
Merkel encodes grip
pacinian: vibration
Ruffini: hand posture
two point discrimination tests?
closeness of receptor fields
which nerves are smallest? slowest? why?
nociceptor: free nerve endings, slow, so you can pack lots of them in densely
mechanoreceptors for touch are large or small? have myelin?
large myelinated
what innervated face dermatome?
trigeminal
dermatomes only in one band of skin?
lots of overlap
can spread to one dermatome on either side
how to tell dermatome vs. peripheral nerve?
dermatome affects the entire length usually because the problem is proximal
3 zones of trigeminal?
opthalmic
maxillary
mandibular
