Neuroanatomy - 10 Motor Systems

based on pptx "10a - 2025 motor systems 1 & 2"; LACKS INFO on gamma loop and details on certain confusing slides

voluntary goal-directed movements

in order to make ____________ : decision to move, ID and locate target, know position of limbs and body, form a plan of action, execute plan

descending motor

the cerebellum and basal nuclei have separate input to ____________ pathways

IX

motor neurons are primary found in lamina ____ of the spinal cord

motor unit

a _______ is a muscle group that all contracts together, innervated by the same motoneuron

central pattern generators

__________________ are circuits of interneurons that do coordinated, multisegmental rhythmic cyclical motor activities and basic rhythmic patterns

supraspinal centers, sensory receptors

central pattern generators receive input from ___________ and ____________

modulation to environmental conditions

the supraspinal center input to central pattern generators is for _________________

feedback to the spinal cord (but not necessary)

the sensory receptor input to central pattern generators is for _________________

sensory, descending pathways, collaterals from motoneurons

motor related neurons and motoneurons receive input from _______, _______, and _______

• corticospinal

• vestibulospinal

• reticulospinal

• rubrospinal

• tectospinal

the descending motor pathways are: (5)

interneurons

the five main descending pathways terminate primarily on ___________

• primary motor M1

• secondary areas (preM, SMA)

• PPAC

• cingulate gyrus

main cerebral areas of motor control are:

within and between hemispheres

intracortical communication of motor areas move ______ and _________ _________

cerebellum

general afferents to motor areas from the ____________ do motor planning, smoothing ongoing movements, assist in motor learning, and posture, balance, and equilibrium

basal nuclei

general afferents to motor areas from the ____________ do motor planning and execution, and scaling amplitude and velocity of movements

4

the primary motor area is brodman’s area ___

specific well defined

the primary motor area does execution of ____________________ motor responses

distal

the primary motor area does stimulation of individual cells or small groups of cells for discrete movement especially in _______ muscles

V

the primary motor area has a thick layer __ of pyramidal cells

6

the secondary motor areas are brodman’s area ____

frontal

the SMA and preMC are in the ______ lobe

SMA

the _____ is more superior in the secondary motor cortex

• goal oriented

• movements based on memories

• movements req interlimb coordination

the secondary motor areas are involved in the planning of more complex motor responses like _______________(3) and the initial phases of movement

proximal and axial

the secondary motor areas control ___________ muscles moreso

• M1

• reticular formation

• spinal cord

the secondary motor areas send major efferents to: (3)

M1

random finger movements are done by (M1/SMA/both)

both

movements planned and executed in a specific order are done by (M1/SMA/both)

SMA

movements that are planned but not executed are done by (M1/SMA/both)

contralateral paresis of voluntary movements

an isolated M1 lesion would cause ____________________

proximal

with an isolated M1 lesions, some movement of (proximal/distal) limb segments is often regained

distal

with an isolated M1 lesion, (proximal/distal) muscles may remain paralyzed

apraxia

_______ is difficulty appropriately using the limb during purposeful tasks despite the ability to move the limbs

5, 7

the PPAC is brodman’s areas ______

• preparations for movement guided by sensory stimuli

• initiation of movement

the function of the PPAC is __________________ and ___________

• integrates input from sensory systems

• creates a map of space

• computes limb/body trajectory

in preparation for movement, the PPAC does _______________, ________________, and _______________

secondary motor areas

motor related efferents from the PPAC are primarily headed to the ______________

somatosensory, visual, auditory, vestibular

the PPAC integrates sensory information from the ____________, ___________, ___________, and ___________ systems

astereognosis

___________ is the inability to recognize objects by touch alone

cingulate gyrus

the _______________ may have a small contribution to the corticospinal tract, projections to M1, and a possible role in movements that have a motivational or emotional component

frontal, supplemental, parietal

the three eye fields are ______, _______, and _______

occipital

the visual association cortex is in the _________ lobe

T

T/F: many of the descending fiber paths from motor areas also have fibers originating in non-motor regions of the cortex

lateral

the (medial/lateral) system of descending motor control pathways has a primary effect on the motoneurons of more distal muscles

medial

the (medial/lateral) system of descending motor control pathways has a primary effect on the motoneurons of more proximal and axial muscles

F; BILATERALLY

T/F: the medial system of descending motor control pathways often has effects more unilaterally

• lateral corticospinal

• rubrospinal

tracts in the lateral system of descending motor control pathways:

• anterior corticospinal

• vestibulospinal

• reticulospinal

• tectospinal

tracts in the medial system of descending motor control pathways:

• pyramidal cells in:

  • M1 (30%)

  • secondary motor areas (30%)

  • parietal regions (40%) - and maybe cingulate

the corticospinal tract axons originates from: (and are what percent:)

does, pyramidal decussation

the lateral corticospinal tract (does/does not) decussate; if so, where?

does not (in the brainstem)

the anterior corticospinal tract (does/does not) decussate; if so, where?

somatotopically

the corticospinal tract is _____________ arranged

anterior horn, VII, VIII, IX

the corticospinal tract primarily synapses in the _______ horn of the SC in laminas __________

T

T/F: some axons of the corticospinal tract synapse directly to motoneurons, while others synapse to interneurons

distal

the lateral corticospinal tract synapses on interneurons that will then go to motoneurons for (proximal/distal) muscles

proximal

the anterior corticospinal tract synapses on interneurons that will then go to motoneurons for (proximal/distal) muscles

EPSPs; EPSPs or IPSPs

the corticospinal tract causes _____ on interneurons, which in turn cause ______ on motoneurons

s1, s2; sensory transmission

some fibers from ___ and ___ travel in the corticospinal tract to the posterior horn of the spinal cord to modulate _____________

• reticular formation in the pons and medulla

• inferior olivary nucleus (medulla) with cerebellar inputs

the collaterals of the corticospinal tract go to the ____________ and ___________

corticospinal collaterals

_____________ are the origin for climbing fibers

bilaterally

the anterior corticospinal tract has terminations ____________

lenticulostriate (off of MCA)

the internal capsule is vascularly supplied by the ___________ artery

posterior cerebral PCA

the midbrain is vascularly supplied by the ___________ artery

anterior spinal

the medulla is vascularly supplied by the ___________ artery

arterial vasocorona

the spinal cord is vascularly supplied by the ___________ artery

red nucleus

the origin of the rubrospinal tract is the __________

ipsilateral motor areas

the red nucleus receives input from the _________________ of the cerebral cortex, and the cerebellum

contralateral cervical spinal cord

after axons of the rubrospinal tract leave their origin, they travel to the ________________

contralateral UE flexor

the rubrospinal tract primarily influences ___________________ motoneurons

red nucleus / ventral tegmental decussation (midbrain)

after leaving their origin, the fibers of the rubrospinal tract decussate at the level of the _____________

proximal, axial, balance, orientation of head

the medial motor systems control _____ and _____ muscles, ________, and ______________

4

there are ___ vestibular nuclei

superior, inferior, medial, lateral

the 4 vestibular nuclei are:

• vestibular apparatus (CN VIII)

• cerebellum

inputs to the vestibular nuclei come from the _________ and the _________

contralateral

the rubrospinal tract travels (ipsilateral/contralateral) in the spinal cord

ipsilateral

the anterior corticospinal tract travels (ipsilateral/contralateral) in the spinal cord

contralateral

the lateral corticospinal tract travels (ipsilateral/contralateral) in the spinal cord

ipsilateral

the lateral vestibulospinal tract travels (ipsilateral/contralateral) in the spinal cord

lateral vestibular

the lateral vestibular nucleus originates from the ______________ nucleus

anterior spinal cord gray area

the lateral vestibular nucleus is located ipsilaterally in the _________________

EPSP

the lateral vestibulospinal tract generally does (EPSP/IPSP) on motoneurons

axial and LE extensors

the lateral vestibulospinal tract generally excites ____ and __________ muscles especially

trunk, LE

the lateral vestibulospinal tract does postural adjustment for the _____ and ____ in response to vestibular apparatus input to help maintain balance

F; EXTENSORS

T/F: the lateral vestibulospinal tract primarily influences flexors

medial longitudinal fasciculus

the medial vestibulospinal tract is also called the ________ ________ ________

BILATERALLY

the medial vestibulospinal tract travels ___________ in the spinal cord

medial vestibular

the medial vestibular nucleus originates from the ______________ nucleus

cervical and upper thoracic

the medial vestibular tract only exists in the _________________ spinal cord only

VII, VIII

the medial vestibular tract primarily synapses in laminas ____ and _____ of the spinal cord

neck

the medial vestibulospinal tract influences ____ musculature

T

T/F: the reticular formation is located throughout the brainstem

paravertebral muscles, limb extensors

the reticulospinal tract controls and modulates motor activity in the motoneurons of the _____________ and _____________

background / stabilization

the reticulospinal tract is involved in providing _________ for primary movements of posture and balance

reticulospinal

the __________ tract modulates sensory information, especially noxious stimuli, in the dorsal horn of the spinal cord

medial

both the medial and lateral reticulospinal tracts are part of the ________ system

medial

pontine (medial/lateral) reticulospinal tract

lateral

medullary (medial/lateral) reticulospinal tract

entire length

both reticulospinal tracts run the __________ of spinal cord

bilaterally ; more ipsilateral than contralateral

the reticulospinal tracts travel ___________ in the spinal cord; but more __________ than _________

excitatory

the pontine reticulospinal tract has a primarily (excitatory/inhibitory) effect on motoneurons

inhibitory

the medullary reticulospinal tract has a primarily (excitatory/inhibitory) effect on motoneurons