What effect does injury to the primary motor cortex have on peripheral muscles?

The brain is divided into two cerebral hemispheres by the ________________.

The occipital lobe is found at the ________ of the brain, while the parietal lobe is found at the ________.

A spinal reflex is a rapid, involuntary response to a stimulus. Tala has an issue with motor areas of her brain. Will her spinal reflexes still function? 

Which of the following body parts would you expect to have the greatest size difference between its area on the motor homunculus and its area on the sensory homunculus?