Motor control

Question 1

what is the difference between declarative and non-declarative memory?

Answer 1

declarative memory: factual information, life events, easily formed/forgotten, available to consciousness

non-declarative memory: procedural memories = skills and habits, less easily formed/forgotten, not available to consciousness (don’t pull up instructions for how to do them e..g driving)

Question 2

what is a ballistic movement? give an example

Answer 2

a pre-programmed movement which is rapid at the expense of accuracy eg. swatting a fly away

Question 3

what is a pursuit/visual feedback movement? give an example

Answer 3

motor command which is continually updated with sensory feedback, highly accurate. eg slow pursuit of a moving car with hand

Question 4

what is the role fo the prefrontal cortex?

Answer 4

control of movement, decision to make a movement

Question 5

what area are the supplementary and pre motor area (SMA + PMA) found in ? what is their role?

Answer 5

area 6

involved in planning movements

Question 6

what areas is the posterior parietal cortex found in?

Answer 6

area 5 and 7

Question 7

what is the role fo the primary motor cortex? what area is it found in?

Answer 7

area 4

it sends output to muscles to bring about the movement

Question 8

what areas of the body have the greater representation in the motor homunculus?

Answer 8

face and hands (have fine control)

Question 9

what is a somatotopic map?

Answer 9

mapping between areas of of motor cortex and muscles of the body

Question 10

how does the paralysis and loss of sensation caused by stroke relate to the side of the haemorrhage?

Answer 10

paralysis and loss of sensation will be contralateral to side of haemorrhage

Question 11

of the SMA and PMA, which one receives sensory info from the upper and lower limb?

Answer 11

SMA = upper limb
PMA = lower limb

Question 12

what sensory information is crucial for coordinated movement?

Answer 12

proprioception, vision and balance

Question 13

what are the main non-cortical brain structures involved in control of movement?

Answer 13

basal ganglia and cerebellum

Question 14

where do the basal ganglia receive input and output from?

Answer 14

Input from prefrontal cortex (decision about making movement)
Output to pre-motor area/cortex via subthalamic nuclei

Question 15

what are the functions of the basal ganglia?

Answer 15

Function:

• Initiates movement by putting motor plan into action (PD - difficulty)
• Plans complex voluntary movement
• Important for motor learning (procedural learning related to routine behaviours or habits)

Question 16

which 2 conditions are caused by disorders of the basal ganglia?

Answer 16

parkinsons’s disease

huntington’s disease

Question 17

what are symptoms of Huntington’s disease and what causes it?

Answer 17

choreas (random involuntary movements), difficulty speaking and swallowing, progressing to general cognitive decline

Inherited - triplet repeat disease

Question 18

where does the cerebellum receive input and output from?

Answer 18

Input: mainly from sensory cortex

Output to primary motor cortex via subthalamic nuclei

Question 19

What are the functions of the cerebellum?

Answer 19

• Coordination and smooth execution of movements

- Motor learning, error detection

Question 20

what does damage to the cerebellum cause?

Answer 20

cerebellar ataxia - poor coordination

Question 21

what are skeletal muscle fibres innervated by?

Answer 21

alpha-motor neurons

Question 22

what is a motor unit?

Answer 22

a functional unit formed by a motor neuron and the muscle fibres it innervates

Question 23

what are collections of motoneurones in the ventral horn also known as?

Answer 23

motonuclei

Question 24

what different body parts do cervical, thoracic and lumbar and sacral motor neurones control?

Answer 24

cervical = arms and upper body
thoracic = trunk
lumbar and sacral = legs

Question 25

how can strength of a muscle contraction be graded?

Answer 25

by recruitment of motor neurons