somatosensory I Flashcards
afferent muscle spindle fibers are?
fiber types?
- annulospiral (Ia)
- flower spray (II)
golgi tendon organ:
senses what?
fiber type?
- muscle force, tension
- Ib
THREE types of fibers in the skin?
- A beta
- A delta
- C
ruffini corpuscle function
joint movement and pressure
what are the FOUR sensory fiber types
A alpha; A beta; A delta; C
what are the FOUR motor fiber types
A alpha; A gamma; B; C
sensory A alpha receptors go to___ in spinal cord
DCML
sensory A beta receptors go to___ in spinal cord
DCML
rank the conduction velocity of the different sensory classes
A alpha > A beta > A delta > C
remember that the FATTER the nerve the FASTER it goes
rank the conduction velocity of the different sensory classes
A alpha > A gamma > B > C
which fibers enter the dorsal horn most laterally
C fiber. the A delta fiber is more medial in the dorsal horn
deformation of encapsulated nerve ending alters?
permeability of ion channels generating a receptor potential
stereognosis=
tracts?
recognition of a 3-D shape, (size, texture); fasciculus gracilis (below t6) and cuneatus
somatosensory tracts
posterior column-medial lemniscus
trigeminothalamic
spinoCbellar
ALS
conductance speed of PCML
fast conducting
relays of PCML
limited convergence (doesn’t dilute the sensations much), limited number of synaptic relays
functional component of PCML
GSA
graphesthesia test
trace a number or letter on someones hand and see if they recognize what you wrote
ascending spinal border cells can send info to
cBellum
post synaptic posterior column pathway
nondiscriminative tactil input
redundant dorsal column system
travels distally with PCML
lateral inhibition definition
blocks out noisy peripheral input so that only the strongest excitatory input is receieved
brodman area 3a gets info from
3b?
muscle spindles
pain thermal touch
describe the relationship between RECEPTIVE fields and HOMONCULUS
SMALL receptive fields are PRECISE so they have a large representation in the homonculus
(lips, fingers, etc.)
cuneocerebellar tract runs
in dorsal column, but it synapses in its own nucleus… not gracile ( upper limb equivalent of PCML)
onuf’s nucleus
sends fibers for somatic innervation of urethral sphincter and anal sphincter S3-4
spinal roots of achilles reflex
S1
spinal roots of cremasteric reflex
L1-L2
spinal roots of bulbocavernosus reflex
S2-4
spinal roots of anal wink
S2-4….. this one is still gross.
kinesthesia=
limb movment
blood supply to trigeminal motor nucleus?
same blood supply as?
- SCA
- long circumferential branches of basilar
- same as principal sensory nucleus
trigeminoCBellar system:
___ connects through restiform body
-pars interpolaris (of spinal trigeminal nuc)
lateral hemisphere of CBellum :
pathway?
fxn?
affects lateral corticospinal tract to help with motor planning for extremities
intermediate hemisphere of CBellum :
pathway?
fxn?
lateral corticospinal tract and rubrospinal tract for distal limb coordination
vermis and flocculonodular lobe of CBellum :
pathway?
fxn?
- proximal limb and trunk coordination of all the “ __spinal” paths
- balance and vestibulo-ocular reflexes (MLF)
