Question

The axons of upper motor neurons leave the cerebral cortex and enters the _______________[Lateral corticospinal tract, Internal capsule], which is made up of white matter. The axons continue to descend into the _________________ [brainstem, spinal cord] where they cross midline at a region called the _________________ [Medial lemniscus, Decussation of pyramids].

Answer 1

Answer:

The correct option will be:

1. Enter- internal capsule.

2. descend into- brain stem

3. region called- decussation of pyramids.

Explanation:

The given question shows the "descending pathway of motor nervous system" which originates in the brain-cerebral cortex region of the brain.

The upper motor neurons carrying the impulse form the brain to lower motor neuron converges and descend into white matter called "internal capsula" through which it continues to descend into the medulla of the brain stem.

Through the brainstem, it descends into the spinal cord at the mid-line at a region called decussation of pyramids neurons moves further to ventral horn of the spinal cord. At the ventral horn, the upper neuron transfers the impulse to lower motor neurons and to effector organs.

Thus, internal capsule, brain stem and decussation of pyramids are the correct options.