Neurohistology Flashcards
pseudounipolar neuron
sensory neuron located in dorsal root ganglia or the sensory ganglia of CN
if the cell body is located in a sensory ganglian where does sensory info enter
brainstem
if the cell body is located in a dorsal root ganglia where do central poscess enter
spinal cord
what types of neurons are associated with senosry receptors
bipolar
pseudounipolar
structure of bipolar neurons
have a cell body, peripheral process, and central process
where are bipolar neurons usually associated with
special senses
what are the sensory receptors for the visual system
rods and cones
what are teh receptors in the vestibular and cochlear ganglion
hair cells
what do sensory receptors vary by
location in body
morphology
velocity of conduction
modality which they carry
what modalities are carried by cranial nerves
olfaction
vision
gustation
audition
___ are inovled with pressure senstation
pacinian corpuscles
receptive field
the area or territory where the receptor resides
exteroceptors
close to surface of the body
types of exteroreceptors
teloreceptors, contact receptors
examples of teloreceptors
rods, cons, auditory hair cells
function of chemoreceptors in hypothalamus
contain chemoreceptors that sample contents of blood
sensitive to osmolarity of blood
function of chemoreceptor in barotid body
for oxygen and CO2 conc in blood
baroreceptor in carotid sinus function
stretch receptor, help with blood pressure regulation
polymodal nociceptor
stimulus may be chemical, thermal, or mechanical
pruriceptor
respond to inscent bite
what stimulated pruriceptors
histamine
examples of non-encapsulated mechanorecpetors
free nerve endings
peritrichial nerve endings
tactile receptors
examples of encapsulated mechanoreceptors
meissner, pacinian, ruffini, muscle spindle, GTO
function of peritrichial nerve ending
detect bending of the hair
merkel disc
dilated dendritic terminal of a pseudounipolar neuron that contacts the merkel cell
functino of merkel cell
help enhanse sensory perception
where are meissner corpuscles located
in dermal papillae with overlying epiderm
function of meissner corpuscle
help with 2 point discrimination
assist in reading braille
where are muscle spindles found
only skeletal muscle
nuclear bag
has central non-contractile region containing many nuclei
has contractile polar ends
nuclear chain fiber
more slender
non-contraile central region
has polar, contractile regions
function of nuclear chain fibers
detecting changes in muscle length
static nuclear bag fibers
detect changes in muscle length
dynamic nuclear bag fibers
detect rate of change of muscle length
what are contractile portion innervated by
gamma motor neurons
what are non-contractile portions innervated by
annulospiral endings
what do annulospinral endings respond to
onset of muscle stretch
what inenrvates the portion of fibers that are at the border between contractile and noncontractile regions
flow spray endings
function of flow spray endings
detect ongoing muscle stretch
where is GTO located
where skeletal muscle fibers insert into a tendor
what type of innervation does GTO have
only sensory ia heavily myelinated fibers
function of GTO
detect tension applying to a tendon
why is there minimal or no regneation of CNS
no schwann cells to help guide axon sprouds
oligodendrocytes release inhibiting factor
astrocyte do not produce enoug growth factor
scar tissue gets in way
general function of sensory receptor
protective
do brain and spinal cord have sensory receptors
NO
