Organ Systems Test 3

Front 1

purpose of upper motor neurons?

Back 1

control posture, balance, and movements

Front 2

purpose of brainstem pathways?

Back 2

maintain posture and balance

Front 3

purpose of motor cortex pathways?

Back 3

regulate fine movements in extremities

Front 4

what are the descending motor pathways in white matter?

Back 4

lateral corticospinal tract
anterior corticospinal tract
vestibulospinal tract
reticulospinal tract

Front 5

what are the ascending proprioreception pathways in white matter?

Back 5

spinocerebellar (ant/post) tracts
gracile and cuneate fasciculi (dorsal columns)

Front 6

in the vestibulospinal tract, what do the vestibular nuclei do?

Back 6

relay head movement
activity from semicircular duct
utricle and saccule receptors to spinal cord

Front 7

where are the vestibular nuclei

Back 7

medulla

Front 8

other purposes of vestibulospinal tract?

Back 8

activates extensors of lower limb and flexors of upper limb
maintain posture and balance

Front 9

what motor neurons do the reticular formation neurons project down to?

Back 9

trunk muscles
extensors of lower limbs
flexors of upper limb

Front 10

where are the reticular formation neurons?

Back 10

pons and medulla

Front 11

what are stereotypical movements?

Back 11

locomotion and postural adjustments

Front 12

what produces the 'anti-gravity' posture?

Back 12

vestibulospinal and pontine reticulospinal pathways

Front 13

how does the 'anti-gravity' posture move?

Back 13

extension of the lower limbs and flexion of the upper limbs

Front 14

what tracts do the corticospinal tracts include?

Back 14

tracts to the brainstem and spinal cord

Front 15

what 3 tracts do the motor cortex (primary, premotor, supplementary) form?

Back 15

corticospinal tracts to the ventral horn of the spinal cord
corticonuclear tract to CN motor nuclei
corticoreticular tract to pontine and medullary reticular formation

Front 16

where does the corticoreticular tract go?

Back 16

projects to pontine and medullary reticular formations.

Front 17

what does the corticoreticular spinal tract do?

Back 17

smooths out general movements by limiting inhibition among extensor muscles of the lower limb

Front 18

where does the lateral corticospinal tract cross?
what does it include?
what does it do?

Back 18

90% crossed in medulla

lateral funiculus

fine control of movement

Front 19

how is the ventral (ant) corticospinal tract arranged?
what does it include?
what does it do?

Back 19

10% uncrossed, but projects bilaterally in spinal cord

anterior funiculus

posture of neck and trunk

Front 20

what motor neurons does the corticospinal tract innervate?

Back 20

alpha and gamma indirectly or directly by interneurons throughout the spinal cord

Front 21

what characterizes the internal capsule of the corticospinal tract?

Back 21

bundle of axons in cerebral hemispheres
common site of strokes

Front 22

CORTICOSPINAL TRACTS

where are the cerebral peduncles?
where are the pyramids

Back 22

PYRAMIDAL TRACT

midbrain
pons

Front 23

what characterizes lower motor neuron disease?

Back 23

lesion of alpha motor neurons interrupts neural input to the muscles
flaccid paralysis and atrophy of muscle

Front 24

in an upper motor neuron disease, what does a stroke in motor cortices do?

Back 24

disrupts the descending control of CN and spinal motor regions

decrease in fine control of extremities

Front 25

what causes spasticity?

Back 25

disruption of cortical projection to reticular formation

Front 26

what reflexes/actions are involved with spasticity?

Back 26

hypertonicity, clasp knife reflex & hyperreflexia (spindle sensitivity)

antigravity posture due to loss of cortical control over reticulo- and vestibulospinal tracts

Front 27

what is the babinski sign?

Back 27

stroking sole of foot elicits fanning of toes (present in newborns)

Front 28

indication of babinski reflex?

Back 28

corticospinal tracts are still unmyelinated

Front 29

what do association areas do?

Back 29

develop strategies for motor programs

Front 30

where are motor programs sent? what do they do?

Back 30

primary motor cortex

fractioned into individual muscle contractions

Front 31

what does the supplementary motor cortex ensure?

Back 31

correct motor sequences independent of external conditions

Front 32

when is the supplementary cortex activated?

Back 32

during mental rehearsal of motor sequence as seen in PET scan

Front 33

when is the premotor cortex important?

Back 33

in conditional motor tasks

Front 34

what do premotor neurons encode?

Back 34

intention to perform a particular movement

Front 35

what does the premotor cortex base its selection of movements upon?

Back 35

external or internal (memory) events

Front 36

what do appropriate movements for a task require?

Back 36

integration of spatial aspects of objects with proprioceptive and other somatosensory information

Front 37

where do motor areas receive sensory input for sensorimeter integration from?

Back 37

posterior parietal
visual cortex

Front 38

where are copies of motor programs fed back into? where are they integrated? what do they predict?

Back 38

somatosensory cortex (efference copy)

incoming sensory information

expected sensation that will occur and assess present and future states of a limb in action

Front 39

what is the forward model?

Back 39

combines efference copy of:
ongoing motor commands (predicted sensory feedback)
actual sensory feedback (visual and somatosensory)
internal model of the dynamics of the arm to estimate the current state of the arm

Front 40

what is self agency?

Back 40

sense that you are the one who is causing or generating an action

Front 41

how is self agency generated?

Back 41

when the efference copy of motor commands matches the subjects intentions

Front 42

what is self ownership?

Back 42

sense that you are the one who is undergoing an experience

Front 43

how is self ownership generated?

Back 43

when the sensory feedback correspond to these intentions

Front 44

what are actions that are self realized and voluntary?

Back 44

sequences of movements that solve a motor problem and involve:
intention
kinematics
goal-object identity
physical consequences

Front 45

what does motor preparation and execution involve?

Back 45

premotor
supplementary and sensori-motor cortex
parts of the inferior parietal cortex

Front 46

what is mirroring?

Back 46

capturing and understanding the actions of self and others at a more involuntary level

Front 47

is mirroring only a motion?

Back 47

no, it also involves the goal and intention of the action

Front 48

what do mirror neurons do?

Back 48

unify action perception and action execution

Front 49

where is the "core mirror area"?

Back 49

inferior premotor cortex and inferior parietal cortex

Front 50

when are the "core mirror areas" active?

Back 50

when performing or observing an action

Front 51

what can observation of an action do?

Back 51

sensitize mirror neurons in premotor cortex such that even involuntary simulations of the actions are produced

Front 52

how are mirror neuron phenomena graded?

Back 52

simple reproduction of actions observed, to activity underlying the goal of the actions

Front 53

when does the activity increase (red in brain model)?

Back 53

when context of an observed action reveals intention

Front 54

how is mirror neuron activity characterized?

Back 54

by high sensitivity to observed action

Front 55

what does mirror neuron activity represent?

Back 55

goal of the action rather than specific movements