FoCM 1 - Upper Limb

Question 1

Define Dermatome vs Myotome:

Answer 1

Dermatome - Area of skin mainly supplied by one spinal nerve

Myotome - Group of muscles supplied by a single spinal nerve root

Question 2

Upper vs lower motor neurons?

Answer 2

Upper motor neuron:

• Originates in motor region of cerebral cortex or brain stem
• Carries motor info to lower motor neurons

Lower Motor Neurons:

• Originate in spinal cord or cranial nerve nuclei
• Terminates in skeletal muscle

Question 3

Differences between an UMN lesion and a LMN lesion

Answer 3

Upper Motor Neuron lesion:

• Increased Tone
• Hyperreflexia
• Weakness
• Upward plantar reflex (normal is downward)

Lower Motor Neuron Lesion:

• Reduced Tone
• Hyporeflexia
• Weakness/atrophy
• Muscle Fasciculation