BioCog 5B movement control

Question 1

extrafusal muscle fibres

Answer 1

• directly attached to bone

- controlled by alpha motor neurons

Question 2

intrafusal muscle fibres

Answer 2

• make up the muscle spindle
• wrapped in afferent fibres = free nerve endings
• activated by gamma neurons

Question 3

golgi tendon organ

Answer 3

• detects stretch

- lies where the spindle is attached to the bone

Question 4

weight dropped on hand

Answer 4

• GTO and MS detect whether it is to heavy or not

- if not arm is put back into place

Question 5

myofibrils

Answer 5

• in extrafusal muscle fibres
• made up of actin and myosin
• myosin builds heads that move by stick, sliding along and releasing from actin strands

Question 6

polysynaptic inhibitory reflex

Answer 6

1. GTO sends signal of too much tension to
2. dorsal root ganglion to
3. gray matter of spinal cord
4. inhibitory interneuron inhibits
5. alpha motor neuron sends inhibitory signal via
6. ventral root to
7. extrafusal muscle fibres

Question 7

doping

Answer 7

• f.e. done by sedating the GTO

Question 8

lateral group

Answer 8

• for independet limb movements

Question 9

ventromedial group

Answer 9

• for balance, body posture and walking

Question 10

cerebellum

Answer 10

• processes motor coordination

- distribution of muscles, timing

Question 11

dentate nucleus and thalamus

Answer 11

• get info from cerebellum to cortex

Question 12

ponatate nucleus

Answer 12

• gets info from cortex to cerebellum

Question 13

damage in cerebellum

Answer 13

• problems timing movements
• tremors
• especially at the end of movements

Question 14

information processing for motor

Answer 14

1. parietal for space, temporal for audition and memory, occipital for visual and plans from prefrontal
2. tranfered to both supplementary and premotor cortex
3. motor cortex

Question 15

supplementary motor cortex

Answer 15

• sequences of movements

- SMC

Question 16

premotor cortex

Answer 16

• planning movements

- PMC

Question 17

limb apraxia

Answer 17

• damage in left parietal

- wrong body parts, movements or sequences

Question 18

constructural apraxia

Answer 18

• more of a visual problem

- can not group parts into wholes

Question 19

basal ganlia

Answer 19

• gate for stoppin movements to be executed

- consits of globus pallidus, caudate and putamen

Question 20

direct path

Answer 20

• caudate and putamen inhibit globus pallidus INTERNAl
• thalamus is inhibited less
• > promotes movement

Question 21

indirect path

Answer 21

• caudate and putamen inhibit globus pallidus EXTERNAL
• subthalamic nucleus is less inhibited
• thalamus is more inhibited
• > supresses movements

Question 22

latentca difference

Answer 22

• time between direct and indirect path

- door is still open for movement

Question 23

substantia nigra

Answer 23

• produces dopamine 1 and 2

- both promote movement

Question 24

Parkinson’s disease

Answer 24

• degeneration of dopaminergic neurons in substantia nigra

- treated with dopamine precursor L-DOPA

Question 25

Huntington’s disease

Answer 25

• loss of neurons in caudate and putamen