nervous 2 Flashcards
________ are the areas innervated by each nerve
dermatomes
what are the 4 modalities of the somatosensory system?
proprioception, mechanoreception, thermoreception, nociception
first order neurons are:
second order nuerons are:
third order neurons are:
primary afferent neurons and sensory receptors
spinal cord neurons
thalamocortical neurons
first order neurons connect the _____ to the _____. They carry info from _____ into the _____. Motor efferent fibers leave the ___
PNS, CNS
tissue, dorsal horn
ventral horn of the spinal cord to innervate tissue
primary afferent neurons are ______ in structure, their cell body lies in the ____
pseudo-unipolar
dorsal root ganglion
is a terminal a synpase?
no
A alpha is mostly
propriception
A beta is mostly
mechanoreception
A delta is
fast nociception and temperature
C is
slow nociception, temperatuer, itch
sematosensory receptors can be specialized structures or_____. Can be modality specific or ______. they have _______
free nerve endings
multimodal
specific receptive fields
a smaller receptive field allows for_____, but requires ____.
More sensitive areas have _____.
more acuity, more receptors
smaller receptive fields
Recptive fields must be discrete, but ____. ______ effectively removes weaker stimuli that surround a strong stimulus
most stimuli arent
laterl inhibition
phasci receptors are _____, they stop firing when ____, provide indo about _____ in stimulus
fast adapting
stimuli are constant
change
tonic receptors are_____, and they have no _____. Provide info about _____
slow adapting
adaptation
steady state stimulus
proprioceptors are located:
they are usually:
innervated by:
within muscles, tendons, and ligaments, and joints
specialized structures like golgy tendon organs, muscle spindles, and joint kinesthetic receptors
A alpha fast conducting fibers, usually rapid adapting
mechanoreceptors sense:
they are innervated by
there are 4 types
all aspects of touch, pressure, vibration, movement
A beta
merkel discs, meissners corpuscles, ruffini corpuslcs, pacinain corpuscles
Merkel Discs measure:
located in the:
receptive field is:
they are ____ adapting
dense in
sustained, light touch, pressure, fine details
epidermis
small
slowly
fingertips, genitalia, lips
Meissner Corpuscles are located:
receptive field is
____ adapting
the sense:
in supercicial layers of skin
small
rapid
light touch, movement of textures across skin
Ruffini corpuscles lie:
receptive field is:
they sense:
____ adapting
parallel to the skin
large
skin tension, stretch produced by digit or limb movements
slow
pacinian corpuscles are located:
receptive field is
they measure/sense
____ adapting
in subcutaneous tissue
large
deep pressure, vibration, fine surface textures
thermoreceptors are____ nerve endings
kinf of nerve fibers:
the sense:
warm:
cool:
free
A delta or C
sudden changes in skin temp
30 to 43, above 43 nociception
10 to 25, below 15 nociception
thermoreceptors have
transient receptor potential ion channels, non selective cation channels, each one has distinct terminal activation and inactivation
birds are insensitive to capsacian becaude
they have a mutation in TRPV1 receptors making them not feel it
the DCML pathway senses
fine touch, pressure, proprioceptive sensations
the spinothalamic tract senses
crude touch, pain, temp
the thalamus acts as a____
___ and ___ nuclei relay info from the spinal cord the brain cortex
relay station
VPL, VPM
somatosensory information asends through the thlamus ordered to _____.
areas with greater sensory receptor innervation typically are represented by
which area of the body it came from
a larger portion of the cortex
the _____ is a topographic mp of each whisker
barrel cortex
