Final answer:
The area postrema in the brain is responsible for the digestion of toxic materials.
Step-by-step explanation:
The part of the brain responsible for the digestion of toxic materials is the area postrema. Located next to the fourth ventricle, it is not restricted by the blood-brain barrier, allowing it to respond to chemicals in the bloodstream, including toxins that stimulate vomiting.
Damage to the area postrema could impair the brain's ability to detect and respond to toxic substances, leading to their digestion rather than being eliminated from the body.