Motor Pathways

Question 1

What and where are the upper motor neurons?

Answer 1

Upper motor neurons are neurons in ANY of the motor pathways from the motor cortex of the midbrain to the ventral horn of the spinal cord.

Question 2

What and where are the lower motor neurons?

Answer 2

Lower motor neurons are the neurons making up the peripheral motor component of spinal and cranial nerves.

Their cell bodies are in the ventral horn of the spinal cord their axons pass in the peripheral nerve to the muscles supplied by that nerve.

Question 3

What are the likely effects of damage to the upper motor neurons?

Answer 3

spastic paralysis and hyperreflexia in spinal nerves

Question 4

What are the likely effects of damage to the lower motor neurons?

Answer 4

flaccid paralysis because no information whatsoever can get to the muscles

Question 5

What is the function of nerve axons passing through the posterior limb of the internal capsule?

Answer 5

The axons passing through the posterior limb of the internal capsule are corticospinal And corticobulbar tracts also thalamocortical projections from thalamus to sensory cortex.