Class 17 - Motor system and cerebellum

Question 1

What are parts of the motor system?

Answer 1

Motor cortex, basal ganglia, cerbellum, brain stem, spinal cord, motor neurons

Question 2

What does the posterior cortex do?

Answer 2

Specify movement goals and connect to prefrontal cortex

Question 3

What does the prefrontal cortex do?

Answer 3

Generates movement plans

Question 4

What does the premotor cortex do?

Answer 4

Recognizes movement of others and selects actions

Question 5

What does the primary motor cortex do?

Answer 5

Executes movements

Question 6

What do more complicated movements do to cerebral blood flow?

Answer 6

Increase the blood flow to many different regions

Question 7

What happened when Wilder Penfield stimulated the precentral gyrus?

Answer 7

Produced movement in different parts of the body

Question 8

How many homunculi are there in motor and premotor cortices?

Answer 8

10

Question 9

What are the three types of organization in the motor cortex?

Answer 9

Part of body to be moved, spatial location to which the movement is directed, function

Question 10

How do neurons increase force?

Answer 10

Increase firing

Question 11

Are neurons able to plan and initiate movement?

Answer 11

Yes

Question 12

Motor neurons calculate distance and direction of movement. True or false?

Answer 12

True

Question 13

In imagined and active movement, is there similar brain activation?

Answer 13

Yes

Question 14

What are mirror neurons?

Answer 14

Neurons that fire when we see others make a movement. They encode a complete action and fill in banks when part of a movement is absent

Question 15

What hemisphere are mirror neurons generally located in?

Answer 15

Left hemisphere

Question 16

What are the two ways the prefrontal and posterior cortex use sensory information?

Answer 16

Make movements in response to sensory stimulation.

Provide information to produce or modify complex movements.

Question 17

What is deafferation?

Answer 17

Loss of sensory input (Friedreich’s ataxia)

Question 18

What role does the basal ganglia have?

Answer 18

Modulate the force of movement

Question 19

What are two disorders of too much movement?

Answer 19

Huntongton’s chorea and tourette’s syndrome. Cell death in caudate/putamen

Question 20

What happens in Parkinson’s disease?

Answer 20

Loss of dopamine cells in substantia nigra causing muscular rigidity and difficulty performing movements

Question 21

What are the two pathways in the internal globus pallidus?

Answer 21

Excitatory and inhibitory

Question 22

What happens if the GPi is inhibited? excited?

Answer 22

Thalamus excitation and inhibition respectively

Question 23

What does the cerebellum participate in?

Answer 23

Acquiring and maintaining motor skills

Question 24

What does the flocculus do?

Answer 24

Takes part in balance

Question 25

What does damage to the cerebellum usually result in?

Answer 25

Loss of timing in movement and perceptions, problems with movement accuracy

Question 26

What movements are the brainstem responsible for?

Answer 26

Posture, sex, eating and drinking, walking, grooming and making nests

Question 27

What does the corticobulbar tract do?

Answer 27

Controls facial movements. Projection from cortex to brainstem

Question 28

What does the corticospinal/pyramidal tract?

Answer 28

Controls limbs and body. Ventral portion controls midline (ipsilateral) and lateral portions moves limbs and digits (contralateral)

Question 29

What are ventral horns made of?

Answer 29

Spinal cord motor neurons arranged as a homunculus

Question 30

What is gait ataxia?

Answer 30

Wide based gait, poor turning, staggering to one side “drunk walk”

Question 31

What is dysmetria of extremities

Answer 31

Lack of coordination of movement (ipsilateral to side of lesion). Cannot do alternating movements (dysdiadochokinesis)

Question 32

What is dysphagia?

Answer 32

Impaired ability to chew or swallow

Question 33

What is truncal ataxia?

Answer 33

Problems with the core, lesions to cerebellar vermis

Question 34

What is appendicular ataxia?

Answer 34

Problems with limb movements, lesions to intermediate cerebellar hemispheres

Question 35

What is the lateral cerebellar hemispheres for?

Answer 35

Motor planning

Question 36

What features are affected by cognitive affective syndrome?

Answer 36

Executive functions, visual-spatial functions, language, personality

Question 37

What is the dysmetria of thought hypothesis?

Answer 37

Cerebellum has functional domains that is an integral node in many neural circuits

Question 38

What is being suggested results from atrophy of the vermis?

Answer 38

Autism and schizophrenia

Question 39

What is posterior fossa syndrome?

Answer 39

Lesions to vermis or dentate nucleus causes mutism and personality change (becomes a douche)