The cerebrum (cerebral hemispheres) is the largest part of the human brain, comprising approximately 85% of total brain weight. It is divided into two hemispheres connected by the corpus callosum, and its outer layer — the cerebral cortex — is responsible for higher functions including consciousness, sensory processing, motor control, language, and cognition. The cerebellum is second largest; the medulla oblongata is part of the brainstem.