different types of receptors Flashcards
what are the different types of nerve endings?
free nerve endings and encapsulated nerve endings
free nerve endings
pain thermal tickle itch some touch
encapsulated nerve endings
touch pressure and vibration
what type of nerve senses touch
encapsulated, large diameter, myelinated A fibres
what type of nerve senses pressure
encapsulated, large diameter, myelinated A fibres
what type of nerve senses vibration
encapsulated, large diameter, myelinated A fibres
what type of nerve senses itch
free nerve ending, small diameter, unmyelinated C fibres
what type of nerve senses tickle
free nerve ending, small diameter, unmyelinated C fibres
what are the different touch receptors?
meissner corpuscle
hair root plexus
merkel disc
ruffini corpuscle
which touch receptors are rapidly adapting?
meissner corpuscle
hair root plexus - around hair follicle
which touch receptors are slow adapting?
merkel disc
ruffini corpuscle
meissner corpuscle
tactile
hairless skin - hands, lips, tongue
hair root plexus
around hair follicle
merkel disc
fine touch
free nerve endings
ruffini corpuscle
encapsulated
deep in dermis
sensitive to stretching during movement
what detects pressure
pacinian/ lamellar corpuscle - rapidly adapting
what detects vibration?
all corpuscles
sensation due to combination of rapidly repetitive signals
pain sensation
nociceptors
very little adaptation
everywhere except brain
proprioception
kinesthesia info about muscle contraction, tension in tendons and position of joints slowly adapting muscle spindles tendon organs joint kinesthetic receptors
what is kinesthesia?
perception of motion
what do muscle spindles do?
monitor length of muscle
what do tendon organs do?
protect from excessive tension
what do joint kinesthetic receptors do?
joint position and movement
thermal sensation
free nerve endings
rapidly adapting, but continue to fire at low frequencies
cold receptors
abundant
connected myelinated A fibres or unmyelinated C fibres
between 10-40 degrees
painful if below 10 degrees
warm receptors
between 32-48 degrees
painful if above 48 degrees
thalamic lesion
sensory loss throughout opposite side
brainstem lesion
contralateral sensory loss below face and ipsilateral on face
central cord lesion
asymmetrical and dissociated areas of loss
not all sensations are lost
unilateral cord lesion
contralateral spinothalamic loss with ipsilateral weakness and dorsal column loss below lesion
transverse cord lesion
loss of all modalities - including motor below lesion
