Week 10 - Somatic Nervous System

Question 1

What comprises a motor unit?

Answer 1

an alpha motor neuron and the muscle fibres it supplies

alpha motor neuron - innervates extrafusal muscle fibres that are responsible for muscle contraction

Question 2

What are the two types of upper motor neuron?

Answer 2

corticospinal - cerebral cortex to spinal cord

corticobulbar - cerebral cortex to brainstem

Question 3

Where do the majority of corticospinal fibres cross over?

Answer 3

pyramids of the medulla

Question 4

Where are the cell bodies of lower motor neurons contained?

Answer 4

ventral horn

Question 5

What are the 3 categories of movement?

Answer 5

reflexive

rhythmic

voluntary

Question 6

What area of the motor cortex is responsible for the initiation and planning of movement?

Answer 6

supplementary motor area

also bimanual coordination

Question 7

What is the function of the primary motor cortex?

Answer 7

control of distal musculature

control of fine skilled movements

Question 8

What area of the motor cortex is responsible for the control of movement sequence and preparation for movement?

Answer 8

premotor cortex

also controls proximal musculature

Question 9

What is a mono-synaptic reflex?

Answer 9

a reflex arc that consists of only two neurons

one sensory neuron and one motor neuron

Question 10

What is the function of the basal ganglia?

Answer 10

motor sequence learning

Question 11

What is the function of the cerebellum?

Answer 11

motor adaption

timing and coordination and learning of motor skills