The Structure And Function Of The Human Brain The brain structure is composed of three main parts: the forebrain, midbrain and hindbrain, each with multiple parts. Forebrain The Cerebrum: Also known as the cerebral cortex, the cerebrum is the largest part of the human brain, and it is associated with higher brain function such as thought and action. Nerve cells make up the gray surface, which is a little thicker than our thumb. White nerve fibers beneath the surface carry signals between nerve cells in other parts of the brain and body. Its wrinkled surface increases the surface area, and … Continue reading Brain Structure And Function