Fxn Neuro Lec 37 - Cerebral Cortex: Motor Fxn

Front 1

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

Back 1

1. primary motor cortex (MI), 2. supplementary motor area (SMA or MII), 3. lateral premotor area (LPA)

Front 2

Area 4 of MI is characterized by:

Back 2

giant pyramidal cells of Betz

Front 3

What does MI contain?

Back 3

MI contains a somatotopic map of the contralateral half of the body called the motor homunculus

Front 4

How is MI organized?

Back 4

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

Front 5

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

Back 5

large or giant pyramidal cells in layer V

Front 6

What is the function of MI?

Back 6

primary motor cortex executes voluntary movements

Front 7

What the inputs of MI?

Back 7

tactile and proprioceptive information from the somatosensory cortices and somatosensory association areas

Front 8

What are the outputs of MI?

Back 8

LMNs the brainstem and spinal cord, Red nucleus and reticular formation

Front 9

What is the function of the LPA?

Back 9

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

Front 10

What are the inputs of the LPA?

Back 10

Somatosensory and visual areas, Prefrontal cortex, Cerebellum by a relay with the VLp

Front 11

What are the outputs of the LPA?

Back 11

MI, Brainstem Reticular formation, Spinal Cord

Front 12

What is the organization of the SMA?

Back 12

a crude somatotopic organization: a homunculus lying on its back

Front 13

What is the function of the SMA?

Back 13

plans, programs, and initiates voluntary movements, especially internal guidance (those called on by drives or ideas)

Front 14

What are the inputs to the SMA?

Back 14

Basal Ganglia (via VA and VLa), Somatosensory cortex and areas associated with drives and volition

Front 15

What are the outputs of the SMA?

Back 15

Primary Motor Cortex, Spinal Cord

Front 16

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

Back 16

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

Front 17

What are the inputs to the FEF?

Back 17

visual areas in the parietal and occipital lobes, and the substantia nigra

Front 18

What are the outputs of the FEF?

Back 18

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

Front 19

What do lesions of the FEF result in?

Back 19

voluntary aversive eye movements are impaired

Front 20

A right FEF lesion would cause:

Back 20

a patient’s eyes to look to the right

Front 21

Where does the rubrospinal tract originate?

Back 21

solely from the magnocellular red nucleus

Front 22

What is the function of the rubrospinal tract?

Back 22

facilitate flexor muscle tone

Front 23

What is the function of the corticoreticular system?

Back 23

trigger fixation or stabilization of proximal musculature before performing skilled fine voluntary movements

Front 24

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

Back 24

Corticobulbar tract

Front 25

This pathway arises from Giant Betz cells in layer 5 of MI and synapses on motorneurons of lamina IX

Back 25

Monosynaptic, Direct pathway

Front 26

Are indirect pathways usually monosynaptic or polysynaptic?

Back 26

Polysynaptic

Front 27

Lateral pathways control what type of muscle, proximal or distal?

Back 27

Distal

Front 28

Medial pathways control what type of muscle?

Back 28

Proximal Axial muscles

Front 29

Are medial pathways direct or indirect?

Back 29

Indirect (Synapse on VII and VIII before going to IX)

Front 30

Lesions of this region of cortex result in contralateral paralysis of the upper motor neuron type.

Back 30

Primary Motor Cortex (MI)

Front 31

Lesions of this region cause impairment in performing tasks in response to sensory cues, like visually guided movement or grasp reflex.

Back 31

Lateral Premotor Area (LPA)

Front 32

Lesions of this area result in a general reduction of voluntary movements and poverty of spontaneous speech.

Back 32

Supplementary Motor Area (SMA)

Front 33

Lesions of this area impair voluntary eye movements so that the eyes are directed to the side of the lesion.

Back 33

Frontal Eye Field (FEF)

Front 34

This tract can end directly on lamina IX neurons.

Back 34

Lateral Corticospinal Tract (LCST)

Front 35

Fibers of this tract arise from large pyramidal and Giant Bets cells.

Back 35

Corticospinal fibers

Front 36

These fibers cross at the spinomedullary junction and descend in the lateral funiculus

Back 36

Lateral Corticospinal Tract

Front 37

Fibers of this tract descend ipsilaterally in the anterior funiculus to cervical levels of the spinal cord.

Back 37

Anterior Corticospinal Tract

Front 38

What brainstem pathways are influenced by the cerebral cortex?

Back 38

Rubrospinal tract and Reticulospinal tract

Front 39

face

Back 39

a flat surface on a solid figure

Front 40

What is the function of the Corticorubral Tract?

Back 40

Facilitates flexors in distal upper extremity

Front 41

What is the function of the corticospinal tract?

Back 41

Fine, skilled movements of distal limbs

Front 42

Where does the Corticobulbar tract originate?

Back 42

Head region of MI

Front 43

What is the target site of the Corticobulbar tract?

Back 43

Motor Nuclei of CN V, VII, XII & Parv RF

Front 44

What is the target site of the Corticoreticular Tract?

Back 44

Reticular formation

Front 45

What is the Cortical Origin of the Corticorubral Tract?

Back 45

Upper limb area of MI on lateral aspect

Front 46

What is the Cortical origin of the Corticoreticular tract?

Back 46

MI, LPA & SMA