Pyramidal Tract

Front 1

functions of the pyamidal tract

Back 1

voluntary discrete, skilled mvmts of distal muscles of limbs and control of muscles involved in speech and vocalization

Front 2

what is the sensorimotor cortex?

Back 2

precentral gyrus, postcentral gyrus, premotor cortex

Front 3

what is the precentral gyrus?

Back 3

ba 4; primary motor cortex

Front 4

what are pyramidal cells of betz?

Back 4

3% corticospinal fibers, large motor neurons in 5th layer cerbral cotex of areas 4 and 6, send anox directly to anterior horn cells (N3), highly skilled mvmts

Front 5

postcentral gyrus?

Back 5

1/3 axons, ba 3, 1,2 primary sensory cortex

Front 6

premotor cortex and frontal eye field

Back 6

1/3 axons sensorimotor cortex, ba 6 and ba 8

Front 7

supplementary motor area? and location

Back 7

ba 6, in front of paracentral lobule, needs stronger stimulusxon

Front 8

1st order neuron

Back 8

cell body in cerebral cortex

Front 9

2nd order neuron

Back 9

internuncial neuron in ant. gray column spinal cord, short a

Front 10

3rd order neurone

Back 10

ant gray column sc, innervates skeletal msucle, final pathyway lmn

Front 11

what are umn and function?

Back 11

first order neuron in motor area of cerebral cotex, connect w/ motor nucli in ant. horn sc (2nd order, initate simpulses to skeletal ms

Front 12

lmn and function?

Back 12

located in ant horn sc, pass by peripheral nerve

Front 13

what happens when umn are lesioned to the lmn

Back 13

produces hyperreflexia or spasciticy

Front 14

reflex arcs?

Back 14

1st order directly snapse with 3rd order, fast, maintain muscle tone and posture

Front 15

what happens when one component of reflex arc inhibited

Back 15

reflex abolished

Front 16

flow of corticospinal tract?

Back 16

cerebral cortex -> forms corona radiata -> internal capsule -> cerebral peduncles -> pons -> pyramids -> pyramidal decussation

Front 17

lateral cst? how many crossed and where terminates?

Back 17

75-90% terminated ant. gray column sc, located on cx in lateral funiculus sc

Front 18

ant cst?

Back 18

10-15% uncrossed, eventually cross b4 terminate on ant. horn cells in cervical and upper thoracic regions

Front 19

terminations of pyramidal tract fibers?

Back 19

55% - cervical, 20% thoracic, 25% sacral and lumbar

Front 20

areas which exhibit clonus?

Back 20

gastrocnemius, flexors of fingers, quadriceps femoris

Front 21

pyramidal vs extrapyramidal tract, which one + lmn?

Back 21

pyramidal, extra -

Front 22

corticobulbar tract from where?

Back 22

ba 4, ba 6, 3, 1 2, end at midbrain

Front 23

where does corticobulbar tract project to?

Back 23

motor nuclei 3-12 not 8
parts of reticular formation in pons and medulla

Front 24

what is reticular formation?

Back 24

area in midbrain made of nerves, relay station wihch receieves

Front 25

fxns and innervations of facial motor nucleus

Back 25

innervates upper 1/2 face, innervations both contra and ipsilateral cerebral cortex

Front 26

fxns/ innervations ventral facial motor nuc

Back 26

innervates lower 1/2 fface, only contralateral innverations

Front 27

central facial paralysis

Back 27

umn lesion of corticobulbar tract- some fxns retaied, paralysis on lower 1/2 of face on opposite side of lesion

Front 28

belly's palsy

Back 28

lmn lesion of facial n or motor nuc, complete paralysis of 1/2 of face on same side of lesion

Front 29

fxns and innervations hypogloyssal nuc

Back 29

controls genioglossus ms of tongue, draws root tongue forward to OPP side, contralateral innervations

Front 30

umn lesion hypoglossal nuc?

Back 30

tongue point to opp side of lesion

Front 31

origin and termination of tectospinal and tectobulbar tract

Back 31

origin: superior colluculus, termination at ant gray column (rexed laminae 6, 7, 8) in upper cervical sc

Front 32

fxn tectobulbar/spinal tract

Back 32

mediate reflex postural mvmts in response to visual and auditory stimuli (head turning and eye mvmts)

Front 33

fibers of midbrain level tectospinal/bulbar tract?

Back 33

cross immediately in dorsal tegemental decussation

Front 34

fibers of medullary level tectospinal/bulbar tract?

Back 34

incorporated in medial longitudinal fasiculus

Front 35

origin rubrospinal?

Back 35

red nuc at level of superior colliculus

Front 36

fibers rubrospinal?

Back 36

x immediately in ventral tegmental decussation -> descend down brainstem -> enter lateral funiculus sc

Front 37

what is special about red nucleus neurons?

Back 37

connectoin and indirect pathway of afferent impulses thru cerebral cortex and cerebellum- influence alpha/gamma of sc

Front 38

termination rubrospinal

Back 38

internuncial neurons (ant gray column)

Front 39

fxn rubrospinal

Back 39

influence tone control in flexor ms groups, inhibits extensor alpha, beta, gamma mn, esp distal parts of arm

Front 40

origin interstitiospinal tract

Back 40

interstitial nuc of cajal ->accessory oculuomotor nuc

Front 41

termination interstitosp 7 and 8inal tract

Back 41

ant. horn up cervical levels sc including laminae

Front 42

lat vestibulospinal tract origin

Back 42

lat. vestibular nuc

Front 43

lat vestibulospinal tract termination

Back 43

rexted laminae 7 and 8 or alpha mn 9 on all cervical cord seg

Front 44

lat vestibulospinal tract fxns

Back 44

excites extensor mn innervating neck, back, forelimb, and hindlimb ms

Front 45

med vestibulospinal tract origin

Back 45

med vestibular nuc

Front 46

med vestibulospinal tract termination

Back 46

rexed laminae 7 and 8

Front 47

med vestibulospinal tract fxns

Back 47

excites nec and back mn

Front 48

what are the 2 reticulospinal tracts?

Back 48

pontine recitulo, medullary

Front 49

pontine reticulospinal origin

Back 49

reticular formation in pons

Front 50

pontine reticulospina fxns

Back 50

facilitate extensor mn

Front 51

medullary reticulospinal tract fxn?

Back 51

inhibit extensor mn