Control of Movement (Week 7-8)

Question 1

What are the 3 types of neurons in the spinal cord?

Answer 1

Sensory relay neurons
Interneurons
Anterior motor neurons

Question 2

What are the 2 types of anterior motor neurons?

Answer 2

Alpha motor neurons

Gamma motor neurons

Question 3

What is an alpha motor neuron?

Answer 3

A type of anterior motor neuron.
Give rise to large type A alpha motor nerve fibres, which branch many times after entering muscles, to innervate large skeletal muscle fibres.
Stimulation results in contraction of between 3 and several hundred motor fibres.
It + the fibres innervated = a motor unit

Question 4

What is a motor unit?

Answer 4

An alpha motor neuron + the fibres of muscle it innervates

Question 5

What is a gamma motor neuron?

Answer 5

A type of anterior motor neuron.

Give rise to smaller type A gamma motor nerve fibres, which innervate intrafusal fibres

Question 6

What are intrafusal fibres?

Answer 6

Are in the middle of the muscle spindle

Question 7

Jacksonian March

Answer 7

Progression of motor movements during an epileptic seizure from one region of the body to the next.
Movements resemble purposeful voluntary movements.

Question 8

5 sections of the supplementary motor area

Answer 8

Supplementary motor area proper (F3)
Pre-supplementary motor area (F6)
Dorsal premotor cortex (F2)
Pre-dorsal premotor cortex (F7)
Ventral premotor cortex (F4 & F5)

Question 9

3 steps of voluntary movement

Answer 9

Perception - where? External environment
Decision - what action should be taken?
Execution - the correct areas of the nervous system

Question 10

Dorsal visual stream

Answer 10

Responsible for ensuring accurate movements (even if deceived by environment)
Provides a separate series of visual information to the parietal cortex