5b - Motor Systems & Action

Question 1

what is the function of the basal ganglia?

Answer 1

• receive major input from the cerebral cortex

- project back to cerebral cortex via thalamus

Question 2

what are the 4 neural circuits that involve the basal ganglia?

Answer 2

• motor loop
• occulomotor loop
• prefontal loop
• limbic root

Question 3

what is the motor loop related to?

Answer 3

movement

Question 4

what is the occulomotor loop related to?

Answer 4

eye movements

Question 5

what is the prefontal loop related to?

Answer 5

decision making

Question 6

what is the limbic root related to?

Answer 6

emotions

Question 7

what does the basal ganglia contribute to movement?

Answer 7

• assist in motor learning
• responding to rewards
• involved in motor planning
• assists in controlling muscle force, speed and size
• determine which limb trajectory is most efficient

Question 8

def: modulates the actions of the spinal motor circuits

Answer 8

the brainstem

Question 9

what are the 2 pathways that the brainstem project to the spinal cord in?

Answer 9

medial and lateral

Question 10

def: parts of the basic postural control system, controls the axial muscles and proximal limb muscles

Answer 10

medial brainstem pathway

Question 11

what descending pathways does the medial brainstem pathway include?

Answer 11

• vestibulospinal
• reticulospinal
• tectospinal

Question 12

def: concerned with goal directed limb movements and predominantly control muscles of the limbs

Answer 12

lateral brainstem pathway

Question 13

what descending pathway does the lateral brainstem pathway include?

Answer 13

rubrospinal tract

Question 14

def: reticular formation, maintains posture and maintains muscle tone, mainly involved in extensor muscles

Answer 14

reticulospinal pathway

Question 15

def: vestibular nuclei, controls posture and balance, affects orientation of head and body, involved in anti gravity muscles

Answer 15

vestibulospinal pathway

Question 16

def: superior colliculus, coordinates head and eye movement

Answer 16

tectospinal pathway

Question 17

def: red nucleus, excitatory influence on motoneurons innervating proximal upper limb flexors

Answer 17

rubrospinal pathway

Question 18

where is the region in the brain that initiates walking?

Answer 18

• in the brain stem

- called the Mesencephalic locomotor region (MesLr)

Question 19

def: initiates walking, connects to the reticular formation, triggers the CPG

Answer 19

Mesencephalic Locomotor Region - MesLr

Question 20

def: integrates information that it receives from many locations around the body, sends this location to the motor planning areas and descending tracts

Answer 20

cerebellum

Question 21

the _______ receives the sensory feedback copy, called the efference copy, and compares it to the actual received feedback

Answer 21

cerebellum

Question 22

the _______ acts with the cerebral cortex to produce skilled movements by coordinating the activities of groups of muscles and also makes muscles smooth and activates muscles at the same times

Answer 22

cerebellum

Question 23

what are the 3 general zones of the cerebellum?

Answer 23

1. vestibulocerebellum
2. spinocerebellum
3. cerebrocerebellum

Question 24

def: receives input from the vestibular nuclei regarding neck proprioception and visual input, projects back to vestibular nuclei, is located inside the cerebellum

Answer 24

vestibulocerebellum

Question 25

def: contains the vermis and intermediate cerebellar hemisphere, receives input related to spinocerebellar tracts, medial area

Answer 25

spinocerebellum

Question 26

def: contains lateral cerebellar hemispheres, receives input from cortical areas, projects back to cortical areas via the dentate nucleus

Answer 26

cerebrocerebellum

Question 27

what are the 2 hemispheres within the spinocerebellum

Answer 27

vermis and intermediate cerebellar hemisphere

Question 28

what does the vermis use to connect to the brainstems descending pathways and which pathways?

Answer 28

- the fastigial nuclei | - connects to the descending medial tracts

Question 29

what is the name of the cerebrocerebellar hemisphere?

Answer 29

lateral hemishphere

Question 30

where does the lateral hemisphere project to and for what function?

Answer 30

- projects to cortical areas for motor planning

Question 31

where does the vestibulocerebellum get its info from?

Answer 31

from visual receptors and neck proprioception

Question 32

where does the vestibulocerebellum project to and for what function?

Answer 32

via the vestibular nuclei and projects towards areas involved in head and body orientation

Question 33

def: problems with trajectory or placement of body parts during movement

Answer 33

dysmetria

Question 34

def: abnormalities with rapid alternating movements, deficits in the rate of alternation or completeness of the motor sequence

Answer 34

dysdiadochokinesis

Question 35

def: coordination problem, will walk with a wide base of support and deviate from the path

Answer 35

gait ataxia

Question 36

what structure has these functions: - involved in planning and online control of movement - integrates sensory information that comes from different sensory modalities - areas of space can be described through others sensory systems rather than just eyes - plays a role in working spatial memory and identifying oneself in space

Answer 36

posterior parietal cortex (PPC)

Question 37

what are the 5 suborganizations of the PPC?

Answer 37

1. parietal eye field 2. parietal arm field 3. parietal grasp field 4. parietal face field 5. parietal foot region

Question 38

what is the supplementary motor area involved in?

Answer 38

- movement sequences from memory - important to bimanual movements - has a role in learning

Question 39

what is the premotor cortex involved in?

Answer 39

- involved in the selection of movement from external cues - involved in planning, reaching, and grasping movements - role in decision making

Question 40

def: connects to alpha motor neurons to activate muscles, assist in adapting movements based on conditions, relates to muscle force, determines direction of movement

Answer 40

primary motor cortex (M1)

Question 41

how can we determine the direction of movement if neurons activate during all directions of motion?

Answer 41

we sum up the motion vector that is associated