Question

1. Which of the following is considered to be an indirect motor pathway?

   		Corticobulbar tract
   		Corticospinal tract
   		Spinocerebellar tract
   		Spinothalamic tract
   		Tectospinal tract

Answer 1

corticospinal tract.

The corticospinal tract is involved in voluntary movements. It is a major tract that carries movement related information from motor cortex to the spinal cord. The neurons that travel in the corticospinal tract are called upper motor neurons. They form connections with neurons called lower motor neurons, which carry movement related impulses to muscle, causing it to contract.

The indirect pathway is a circuit in basal ganglia, which plays a role in the inhibition of movement, by inhibiting the thalamus to send excitory messages to the motor cortex. Thus the indirect pathway helps to prevent the unwanted muscle movements, by inhibiting the corticospinal tract.