Movement control

Question 1

POSTURE

Answer 1

Stable position on which movement superimposed

has to be maintained to be able to move

Question 2

Hierachy of control

Answer 2

• spinal cord
• brain stem
• cerebrum
• cerebellum
• basal ganglia

Question 3

Important things before movement

Answer 3

Tone - needs to be maintained

Posture

Balance

Question 4

What are the 3 systems that control and feedback for balance?

Answer 4

Visual

Vestibular

Propriception

Question 5

What controls the initiation of voluntary movement?

Answer 5

basal ganglia

supplementary motor area

Question 6

What is Abulia?

Answer 6

Clinical case where initation of movement is almost impossible even though all other elements of motor system are intact

Causes by: lesions on supplementary motor area

Question 7

What monitors control messages and actual position of the body during movement?

Answer 7

Cerebellum

• compares signal from cerebrum with that from periphery
• detects mismatches
• involved in error correction
• smooth movement coactivation
  
  • alpha/gamma?

Question 8

What stops the movement on reaching the goal so to speak?

Answer 8

Basal ganglia and cerebellum

• relies on feedback to predict the end point
• from the sensory recptors and system

Question 9

Prefrontal Cortex

function

Answer 9

Ideas and motivation

Blood supply: Ant cerebral artery

Question 10

Premotor cortex

Answer 10

function:

idea, movement, conceptualization

blood supply: MCA

Question 11

Supplementary motor cortex

motor association cortex, secondary motor cortex

Answer 11

function:

plan, strategy

blood supply: ACA

Question 12

POsterior parietal cortex

Answer 12

function:

• analysis sensory info related to postulated movement esp visual
• activates supplementary motor area and premotor cortex to plan movement

Question 13

What is the Cerebellum key for?

3 things

what is its blood supply?

Answer 13

• balance
• coordination
• motor memory

blood supply:

3 cerebellar arteries / basilar

Question 14

Cerebellum Function

Answer 14

• Motor memory
• coordination
• MONITORS
• COMPARES

what plan to do (motor cortex command) with actually happening (proprioceptive feed back)

CORRECTS if there is a mismatch

Question 15

Basal Ganglia

Blood supply

Function

Answer 15

Mca, lenticulostriate art, ACA, ant choroidal

Function:

• programming
• amplitude settings
• timing sequence
• programme which muscles contract, when and how much

clinical issues:

P.D., Chorea, Athethosis, resting tremor

Question 16

What commands?

Answer 16

Supplementary and pre motor cortex

Question 17

What initiates?

Answer 17

Primary motor cortex

Question 18

Primary motor cortex

function

Answer 18

• Activate spinal motor neurones via cortico spinal tracts (70% + [90-70%] decussate in medulla)
• homunculus – single fasiculus to large muscle groups
• Blood supply: MCA & ACA

Question 19

What is the most common site for stroke?

Answer 19

Internal capsule

lies between the Thalamus and Basal Ganglia

Question 20

Blood supply to the INTERNAL CAPSULE

Answer 20

MCA – lenticulostriate A ; ACA & Ant. Choroidal A

Question 21

Spasticity

Answer 21

velocity dependent resistance to passive movement Mechanism ?

Changes gamma motor neurone & regulatory interneurones ↑ alpha motor neurone activity → ↑↑ stretch reflex

Question 22

Spinal cord

FUnction:

Answer 22

function: activates muscles

signal arrives anterior horn cell

ventral root

common peripheral nerve

muscle synapse - NMJ