Corticospinal tract

The video tutorial by Dr. Morton explains the corticospinal tract, a primary motor pathway for voluntary control, detailing the roles of upper and lower motor neurons. It covers the decussation process, neuromuscular junction, and the differences between pyramidal and extrapyramidal systems. The tutorial also discusses the effects of lesions on motor function, highlighting clinical signs like the Babinski sign.

What is the primary function of the corticospinal tract?

• Sensory perception

• Voluntary motor control

• Involuntary reflexes

• Autonomic regulation

Where do upper motor neurons originate?

• Spinal cord

• Brainstem

• Cerebellum

• Cerebral cortex

What does the motor homunculus represent?

• A map of sensory areas

• A map of auditory areas

• A map of visual areas

• A map of motor control areas

What percentage of upper motor neurons decussate at the pyramids?

• 90%

• 10%

• 50%

• 70%

What neurotransmitter is involved at the neuromuscular junction?

• Dopamine

• Serotonin

• Acetylcholine

• GABA

What is the role of the basal ganglia in motor control?

• Directly controlling muscle contraction

• Providing input to the thalamus

• Controlling sensory input

• Regulating heart rate

What is the effect of a lesion above the decussation point?

• Contralateral deficits

• Ipsilateral deficits

• Bilateral deficits

• No deficits

What is a characteristic sign of an upper motor neuron lesion?

• Fasciculations

• Hypertonia

• Hypotonia

• Muscle atrophy

What is the Babinski sign indicative of in adults?

• Lower motor neuron lesion

• Upper motor neuron lesion

• Normal reflex

• Cerebellar dysfunction

What is the primary difference between pyramidal and extrapyramidal systems?

• Both are indirect

• Pyramidal is indirect, extrapyramidal is direct

• Pyramidal is direct, extrapyramidal is indirect

• Both are direct