Usu Neuro: 13 Cerebral Motor Function

Front 1

Organization:
Motor decisions and motivations arise from which areas?

What area do these regions influence?

Back 1

Association and limbic Areas

They influence the premotor cortical areas.

Front 2

What area is responsible for planning and organizing movement?

What area do these regions influence?

Back 2

The premotor cortical areas.

The premotor area influences primary motor cortex

Front 3

What are the two divisions of the premotor cortical area?

Back 3

The Lateral Premotor Area (LPA)

The Supplementary Motor Area

Front 4

Primary motor Cortex (MI) (and premotor area) project to:

Back 4

The Brainstem and Spinal Cord

Front 5

What dos the brainstem control?

Back 5

Postural and cranial reflexes and projects to the spinal cord

Front 6

What does the spinal cord control?

Back 6

Limb and Trunk reflexes

Simple motor patterns.

Front 7

Output through the basal ganglia influences premotor areas through the:

Back 7

VA and VL nucleus of the thalamus

Front 8

Output from the cerebellum influences premotor and primary motor areas through the:

Back 8

VL nucleus of the thalamus

Front 9

Where Direct pathways from the premotor and primary motor areas synapse in the spinal cord?

Back 9

Lamina IX

Front 10

Medial descending pathways innervate the motor neurons of:

Back 10

Proximal and Axial muscles

Front 11

Lateral descending pathways innervate the motor neurons of:

Back 11

Limbs and Distal muscles

Front 12

Primary motor Cortex (MI) has a somatotopic representation of the:

Back 12

OPPOSITE side of the body.

Front 13

The three areas comprising the frontal agranular cortex concerned with controlling motor activity are:

Back 13

1. Primary motor Cortex (MI)
2. Supplementary motor area (SMA or MII)
3. Lateral Premotor Area (LPA)

Front 14

How is MI organized?

Back 14

the motor cortex is columnar and is organized according to movement components not muscle groups

Front 15

What are the output cells of cortical columns and colonies of neurons in MI?

Back 15

large or giant pyramidal cells in layer V (Upper Motor Neurons)

Front 16

What is the function of MI?

Back 16

Primary Motor Cortex - executes voluntary movements

Front 17

What the inputs of MI?

Back 17

tactile and proprioceptive information from:
-somatosensory cortices
-somatosensory association areas

Front 18

What are the outputs of MI?

Back 18

1. LMNs at the brainstem and spinal cord
2. Red nucleus and reticular formation

Front 19

What would be the result of a lesion to the MI?

Back 19

Contralateral paralysis of the UMN type (Spasticity)

Front 20

What is the function of the LPA?

Back 20

LPA plans, programs, and initiates voluntary movements triggered by and guided by external cues or stimuli

Front 21

What are the inputs of the LPA?

Back 21

1. Somatosensory and visual areas
2. Prefrontal cortex
3. Cerebellum by a relay with the VLp

Front 22

What are the outputs of the LPA?

Back 22

1. Primary Motor Cortex
2. Brainstem Reticular Formation
3. Spinal Cord

Front 23

What would be the result of a lesion to the LPA?

Back 23

Impairment in performing tasks in response to sensory cues.

Front 24

What is the organization of the SMA?

Back 24

A crude somatotopic organization: a homunculus lying on its back

Front 25

What is the function of the SMA?

Back 25

Plans, programs, and initiates voluntary movements

Front 26

What are the inputs to the SMA?

Back 26

1. Basal Ganglia (via VA and VLa)
2. Somatosensory cortex and areas associated with drives and volition

Front 27

What are the outputs of the SMA?

Back 27

1. Primary motor Cortex
2. Spinal Cord

Front 28

What would a lesion of the SMA cause?

Back 28

A general reduction of voluntary movements.

Front 29

What is the function of the Frontal Eye Field (FEF)?

Back 29

Stimulation of the FEF produces conjugate eye movements to the opposite side

Front 30

What are the inputs to the FEF?

Back 30

1. Visual areas in the parietal and occipital lobes
2. Substantia nigra

Front 31

What are the outputs of the FEF?

Back 31

-Superior Colliculus
-Brainstem eye movement gaze centers
RiMLF: vertical gaze
PPRF: horizontal gaze

Front 32

What do lesions of the FEF result in?

Back 32

Voluntary aversive eye movements are impaired.

Eyes are directed TOWARDS side of lesion.

Front 33

Where does the rubrospinal tract originate?

Back 33

The red nucleus

Front 34

What is the function of the rubrospinal tract?

Back 34

Facilitate flexor muscle tone

Front 35

What is the function of the corticoreticular system?

Back 35

Trigger fixation or stabilization of proximal musculature before programming skilled voluntary movements

Front 36

What originates from lamina V of the “head” area of the motor cortex?

Back 36

Corticobulbar tract.

Front 37

What is the pathway of the Lateral Corticospinal Tract?

Back 37

Originates in motor and sensory areas -->
Fibers cross at the spinomedullary junction and descend in the lateral funiculus -->
Terminate in Lam.IX neurons in the spina cord.

Activate distal muscles

Front 38

What is the pathway of the Anterior Spinal Tract?

Back 38

Arises in motor and sensory areas -->
Descends ipsilaterally in anterior funiculus to cervical levels of spinal cord -->
Cross at segmental spinal levels

Influences proximal and axial muscles.

Front 39

What is the pathway of the Corticobulbar Tract?

Back 39

Arises from primary motor cortex -->
Terminates on bulbar motorneurons in CN nuclei of V, VII, and XII -->

Cortical fibers to motorneurons innervating lower face musculature are crossed, while other corticobulbar fibers are bilateral