WEEK 4- Fibro pt 1 Flashcards
what is sensation
transduce, encode and perceive information generated by stimuli arising from both external and internal environments
true or false sensation can be perceived from internal or external environemtnts
true
true or false sensation is only restricted to somatic sensory system
false , can be visual, auditory, vestibular, and chemical systems
true or false a small area of the brain is devoted to somatosensory
false, mcuh of the brain is involved
true or false somatic sensory system is the most diverse sensory system
true
somatosensery information can come from what 3 things
skin
muscles
joints
somatic sensory system can be divide din 3 components
n Muscles, tendons & joints receptors
n Cutaneous mechanoreceptors
n Pain, temperature and coarse touch
what do Muscles, tendons & joints receptors sense
limb position / proprioception
what do cutaneous mechanoreceptord sense
touch pressure vibration
what do nociceptros and thermoreceptors sense
paina nd tempertaure
what receptors sense proprioception
muscle spindles and golgi tendon organ
what receptors sense touch
type 1 cutaneous,
type 2 cutaneous
tactile/touch receptor
lamellar corpuscle
true or false the diameter of touch neurons are much larger than for proprioception
false
a alpha is much larger than a beta
true or false proprioceptor axons conduct info much faster
true
somatic sensation comes form
specialized neurons
somatosensweory (senseory neurons) cell body is lctaed in
DRG
Afferent nerve fibers whose peripheral processes ramify within the….
skin or the muscle fibers
true or false
Action potentials generated in afferent fibres by an event occurring at the skin or muscle propagate along the fibre, past the cell body, and reach fibre synaptic terminals in the CNS.
true
dorsal column medial lemniscus pathway are in charge of what sensations
fine tocuh
conscious prop
vibration
anterolateral system is incharge of what sensation
pain
tenp
crude touch
pressure
Sensory information is conveyed in….
multiple parallel pathways
true or false Mechanoreceptors located in the skin and hair follicles also contribute to proprioception, in addition to touch
true
what other receors contribute to propriocept in addition to touch
Mechanoreceptors located in the skin and hair follicles
where does DCML decussate
medulla = brainstem
where does anterolateal decussate
in the spinal cord = AWC
what kind of fibers are we working with for DCML
a aplha
a beta
what kind of fibers are we working with for anterolateral systenm
adelta
c
name all the cutaneous receptos
type 1 curanepus
type 2 cutaneous
free nerve ending
hair follicle receptor
touch tactile
lamellar corpusc;e
type 1 cutaneous is in charge of
light otuch and vibration
type 2 cutaneous in in charge of
stretch and sustained prssure
lamellar corpuscle is in charge of
high freq vib
sudden change in pressure
hair follicle recep is in charge of
air on skin moving air
tactile touch corpuscle is responsible for
light and low freq vib
free nerve ending is resposnible for
paina nd temp
expkain Transduction mechanisms of a mechanosensory afferent
Membrane of the afferent nerve is sensitive to stretching
Stretching leads to cation channels opening
Depolarization causes generator potential in the fibers
If the cell is sufficiently depolarized, an action potential is generated
what area is lamina 3-4-5
nucleus proprius
where does synapse between 1 neuron and 2nd neuron happen
lamina 3-4 nucleus proridu = where the collaterals are located
what kind of info does fasciculus garcilis hace
Fasciculus gracilis carries signals from lower limbs (below t6)
where does info passing in fasciculus gracilis synapse
synapse in the nucleus gracilis
what kind of info does fasciculus cuneatus hace
upper limbs (t6 and above)
where does info form fascilculus cuneatus synapse
nucleus cuneatus
the dorsal column tract is called the medial lemniscus when …
the 2nd order neuron decussates
where do 2 and 3 neurons synapse in the DCML
thalamus
(vpln)
where do Axons from the thalamus travel to reach the cortex
via the internal capsule
then join the corona radiata
what is a receptor field?
the receptor area which when stimulated results in a response of a particular sensory neuron (for example the area that free nerve ending is resposbile for)
can you ahve small and large receptive fields
yes
if somethign tirggers the receptive field, the neruron in charghe of that field will send info to….
the brain
small receptive field carry
more precise info
large receptive field carry
more broad info
organs for example have large receptive fields this is why … (not from notes a youtibe video to help explain)
we cant pinpoint the location of pain but we say my stoamch hurts
touch in the center of the receptive filed …
increases firing
touch in the surround area of receptive field ….
decreases cell firing
touch outside teh recteptive field /….
has no effect
what is two pint discrimination thresholf
minimum interstimulus distance required to perceive 2 simultaneous applied stimuli as distinct
SHORTEST DISTANCE THAT WE CAN PERCEIVE TWO POINT
the back has highe ror lower two point threshold tahn palm
higher threshold higher distance required to tell that there are two points
on my lips for example do we have a high or low two point discrimation threshhold
low
dont need a large distance to tell that there are two point
true or false LARGE receptor fields means LARGE two point discrimination theshold
true
true or false : size of teh receptive field can predict Two-point discrimination threshold
true
receptive fields are ______ in high acuity regions
small
an example of a higha cuity region is
lips
an example of low acuity region is
back
receptive fields are ______ in low acuity regions
large
true or false youll be able to feel more in smaller receptive fields
true
True or false OTS and PTS use calippers to perform two point discrimination test
true
true or false fingers and lips are not good at discriminating short distance between two points
false
very good
which type of cutaneous receptor is best at reading braille
merkel cell/ type 1 cutaneous
the merkel cell / type 1 cutaneous is located in …
epidermis
dp merkel cell / type 1 cutaneous have small or large receptor fields
small
are merkel cell / type 1 cutaneous slow or fast adapting
slow
what does slow adapting receptor mean ? (from youtube)
receptor keeps responding to a present stimulus = keeps firing action potential
good for detecting size and shape of objects
what do fast adapting receptors do?
activated when the stimulus is there but falls silent if its stays = good for movement detection
the merkel cell / type 1 cutaneous is highly sensitive to what
points
edges
curvature
are meisner corpuscle/ tactile touch rapidly or slow adapting
rapid adapting
do meisner corpuscle/ tactile touch have small or large receptor fileds
small
what are meisner corpuscle/ tactile touch sensitive to
low frequency vibration
are rufinin/ type 2 rapidly or slow adapting
slow
do rufinin/ type 2 have small or large receptor fields
large
where are rufinin/ type 2 located
dermis
what are rufinin/ type 2 sensitive ot
sensitive to cutaneou stretching during movements
hand shaping
do panician/ lamelalr have small or large receptor fileds
large (whole finger /hand)
are panician/ lamelalr fast or slow adapting
fast
what are panician/ lamelalr sensitive to
Highly sensitive to high frequency vibrations (250-350 Hz). Use of tools.
which is the deepest receptor of all cutaneous
lamellar
what is proprioception
Mechanical forces arising from within the body
what info does proprioception have
Provide detailed and continuous information about the
position of the limb and other parts in space
name some proprioceptors
spindles
golgi tendons
joint receptors
vestibular system (head)
what are the two types of muscle spindle proprioceptors
1a afferents
2 afferents
name some characteristsics of 1a afferents
Rapidly adapting cells
Activated by muscle stretching
Convey information about the velocity and direction of movements
name some characteristsics about 2 afferents
Slowly adapting cells
Sustained response about muscle length
Convey information about the static position of limbs
muscles spindles sense
CHANGES IN LENGTH
golgi tendon organs sesne
TENSION
name a type of golgi tedon organ
1b afferents
name some characteristsics of 1b afferents
-Low-threshold receptor
-Branches spreading inside the collagen forming the tendons -Convey information about muscle tension (compression)
what pathway does proprioception follow (think non conscious type)–> NUCLEI DORSALES
upper limbs cuneocerebellar
lower limbs dorsal spino
is clarkes nucleus teh same as nucleus dorsale and if yes which lamina
yes, lamina 7
what do spinocerebeallr tracts do
Regulation of the timing of muscle
contractions necessary for the performance of
voluntary movement
which spinal levels are clarkes nuclei found
c8-l2 anatomy
t1-l2 phgy
true or fasle both cuenocerebellar and dorsal spino tract have tehir synapse in the spinal cord
false,
cuneatus one synapses in accessory nucleus cuneatus in medulla
VPLN in thalamus is for what info
body
VPMN in thalamus is for what info
face
true or false, info in the somatosensory cortex is kept segragraded
true
(homonculus)
true or false, the specific somatosensory organization in the cortex is called teh somatotopic organization
true
true or false Each area contains a separate & complete representation of the body
true
true or false on the homonculus represent teh density of neurons in these areas (ex: large lips = lots of neurons)
TRUE
in the somatosensory cortext generally tell me what the somatotopic organization is
medial = lower limbs
then trunk
then upper limbs
then face most latersl
are different types of receptors segragated in the somatotopic areas
yes
3a area tell you info about what in the cortex
Proprioception
Muscle Spindles
Activated during movements
3b and 1 area tell you info about what in the cortex
cutaneous
pressure and vibartion
area 2 tell you info about what in the cortex
area both modalities
where does most of our info reach in the cortex (3a, 3b, 1, or 2)
3b
where does moderate amount of our info reach in the cortex (3a, 3b, 1, or 2)
3a
where does the elast amount of our info reach in the cortex (3a, 3b, 1, or 2)
1 and 2
Lesion in 3b
= deficits in all forms of tactile sensation from mechanoreceptors
Lesion in 1 or 2
partial deficits
Inability to use tactile information to discriminate texture of an objet (area 1) or the size and shape of objects (area 2)
which barin areas are in charge of learning and memory
amygdala and hippocampus
whoch brain areas are incolved in Proprioception – current state of muscles contraction gain access to circuits that initiate mvst
motor and pre motor cortical areas
