Final answer:
The internal capsule is most associated with carrying motor signals via the corticospinal tract from the brain's cortex to the muscles, despite containing sensory fibers.
Step-by-step explanation:
The internal capsule plays a significant role in the descending motor pathway, particularly involving the corticospinal tract. The corticospinal tract, comprising nerve fibers descending from the cortex, traverses the deep white matter of the cerebrum, navigating between the caudate nucleus and putamen within the basal ganglia. This pathway continues through the midbrain, pons, and medulla, where it forms the pyramids and undergoes decussation at the pyramidal decussation, allowing motor signals to control musculature on the opposite side of the body.
While it is primarily associated with motor control, the internal capsule also contains sensory fibers, such as those from the dorsal column system and the spinothalamic tract. Nevertheless, it is predominantly recognized for its role in carrying motor signals rather than sensory input. This is crucial for the coordination and execution of voluntary muscle movements.