Mechanoreception Flashcards
what is mechanoreception?
the detection of mechanical stimuli (pressure, vibration, tension) by mechanoreceptors through distortion.
what is exteroception?
gives information about things coming into contact with the body
what is proprioception?
knowing where parts of the body are (subconscious)
what is touch?
the sensory experience when mechanoreceptors are excited (CNS)
Physiological classification of mechanoreceptors
describe rapidly adapting mechanoreceptors, what do they tell u?
only fires when force is changing (increase/decrease in pressure)
How fast applying the force
physiological classification of mechanoreceptors
describe slow adapting mechanoreceptors, what do they tell u?
receptor fires whole time force is applied
Magnitude of the force
what is receptive field?
amount of tissue that is governed by one nerve
a smaller receptive field means what?
more detailed information (e.g. fingertips)
better 2-point discrimination
what classifications is a RA I mechanoreceptor?
rapid adapting
small receptive field
what classifications is a RA II mechanoreceptor?
rapid adapting
large receptive field
what classification is SA I mechanoreceptor?
slow adapting
small receptive field
what classification is SA II mechanoreceptor?
slow adapting
large receptive field
what anatomical classification of mechanoreceptor is this?
meissner’s corpuscle
what anatomical classification of mechanoreceptor is this?
pacinian corpuscle
what anatomical classification of mechanoreceptor is this?
merkel cells
what anatomical classification of mechanoreceptor is this?
ruffini ending
what Physiological classification of mechanoreceptor is meissner’s corpuscle?
RA I
what Physiological classification of mechanoreceptor is ruffini ending?
SA II
what Physiological classification of mechanoreceptor is merkel cells?
SA I
what Physiological classification of mechanoreceptor is pacinian corpuscle?
RA II
what is 2 point discrimination test?
- How far apart does it need to be to feel it as two separate points
- Reflects innervation density and receptive field size
Fingertip is very discriminative due to high innervation density and small receptive field
- Reflects innervation density and receptive field size
2 point discrimination test
what nerve endings are PDL mechanoreceptors (PDLMs)?
Ruffini endings SA II
quick revision
what afferents do PDLMs have?
Ab axons
where are the cell bodies for PDLMs?
V ganglion
Mesencephalic nucleus - group of primary afferent cell bodies in the CNS
where are the synapses for PDLMs?
Main sensory nucleus
V nucleus
sensory pathway of PLDMs
are there branched axons from PDLMs?
no, nerves only supply the PDL of one tooth -> easy to localise
the innervation density of PDLMs is higher where?
apex
what is the stimulus for PDLMs?
tension
what is the physiological classification of PDLMs apically? why?
slow adapting
low threshold to activate it
Smaller stimulus apically compared to cervically
what is the phsyiological classification of PDLMs cervically? why?
fast adapting
high threshold
requires higher force to activate it
what is the function of PDLMs?
fine motor control
what is surround inhibition?
presynaptic inhibition -> sharpens touch perception
Inhibits the smaller signals from around the stimulus, enhancing the contrast, to give exact location
occurs during processing at the first synapse: V ganglion and mesencephalic nucleus
what is the sensory pathway for PDLMs?
mechanoreception
processing at first synapse
processing in thalamus
conscious perception - somatosensory cortex
