Mechanoreception No2 Flashcards
what is mechanoreception
physiological process mechanical stimuli detected sometimes sensation of touch but some just feedback info proprioception
what is the purpose of a small receptive field
degree of fine perception - pixel analogy
what are the mechanoreceptors involved in intensity and duration and also velocity
Merkel cells
Ruffini
what type, receptive field nd adaption of merkel cells
SA I
small receptive field
slow adaptation
what type, receptive field and adaptation of ruffini cells
SA II
large receptive field
slow adapting
what mechanorectors roles
velocity
acceleration
vibration
meissner
Paccinian
what is the type, receptive field, adaptation of messier cells
RA I
small receptive field
rapd adaptation
what si the type, receptive field, adaptation of paccinian
RA II
large receptive field
rapid adaptive
what are PDLM’s aligned wth
collagen fibres
what are PDLM’s
ruffini ending deep, large receptive field and slow adapt
what do PDLM’s respond to
PDL tension
where is there more tension on the PDLM
moe tension at apex as move more
what d forces from the labile side of the tooth activate
from labile side only activate mechanoreceps with tension, palatal side
how sesntitve PDLM
very sensitive
small movements: 8.5uM
small forces:
what si the experiment to see fine motor control of PLDM
metal device between teeth
flexible bar peanut
transducer shows tension on peanut without breaking
without PDLM not able to have this fine control
what is stage 1 of sensory pathway
mehanorecpetion
transduction stimulus
propagation along primary afferent
what is stage 2 of sensory pathway
processing at first synapse
bigeminal nuclei or spinal nuclei
what is stage 3 of sensory pathway
processing in thalamus
what is stage 4 of sensory pathway
conscious perception
somatosensory cortex
see general sensory pathway
diagram
what is a dermatome
area of skin innervated by the
trigeminal div (max, man, opthalmic)
single spinal segment
what happens when dermatomes manifest with bac
microorganisms in ganglia such as herpes simplex, shingles
what are the trigeminal afferent nerves
cell bodies in
- V ganglion
- V mesencephalic nucleus
what is the purpose of V mesencephalic nucleus
proprioception
where do he trigeminal afferent nerves enter
at brainstem via trigeminal root
where re the primary afferent cell bodies for V path
V ganglion mesencephalic Nucleus (PDL)
where si synapse for V path
mainly in main sensory nucleus
project to spinal V nuclei as well
where do V path project to
sensory cortex via thalamus contralaterally
oralis, interpliss, cadalis
what is a processing process at the first synapse
surround inhibition (pre syn inhibition) sharpens touch perception
describe surround inhibitor
affected nerves give off branches to inhibitory interneurones, presyn inhibitory to nerves
stop peripheral activation of nerves focused to sharpen edges sometimes faded in middle
what gives a proportional representation of sensory of body
sensory homunculus in somatosenoy cortex
