We'll start with a series of articles on brain anatomy, to provide the reader with an understanding of brain architecture, which will be helpful later on when we discuss other topics. So, let’s enter now into the functions of the Cerebrum!

Finally, let’s zoom in on the part of the Cerebrum called the Cerebral Cortex. The Cerebrum is the largest and most complex part of the human brain, making up about 85% of its total mass. It is responsible for a variety of critical functions, including conscious thought, perception, voluntary movement, and language. The Cerebrum is divided into two hemispheres, which are connected by the Corpus Callosum, a bundle of nerve fibers. These hemispheres are further divided into four main lobes - the frontal, parietal, temporal, and occipital lobes - each with its own unique functions.

The Cerebral Cortex, which is the outer layer of the cerebrum, is essential for processing sensory information. The Cortex is composed of tightly packed neurons and is organized into specific functional areas, including the primary sensory cortex and the association cortex. The primary sensory cortex receives and processes information from our senses, while the association cortex integrates information from different sensory modalities and is involved in higher cognitive functions like attention, memory, and decision-making.

The Cerebral Cortex is comprised of six distinct layers, each with its own specific function. The molecular layer contains few neurons, but is rich in support cells called glia, which help maintain the health of surrounding neurons. The next three layers, known as the supragranular layers, contain the majority of the cortex's excitatory neurons and process sensory information. The last two layers, called the infragranular layers, contain inhibitory neurons and play a crucial role in regulating the cortex's activity and ensuring proper information processing.

The Cerebral Cortex is also heavily folded into hills and valleys, which are known as gyris and sulcis, respectively. This folding allows for an increased surface area of the cortex, enabling more neurons to fit within the skull. The shape and depth of these sulci and gyri can vary between individuals and have been linked to differences in cognitive abilities and brain function.

Beneath the Cortex's surface lies the white matter, composed of myelinated nerve fibers that connect individual neurons, cortical circuits, or entire brain regions to each other. These fibers transmit information between brain regions, and disruptions in the white matter, such as in the case of diseases like multiple sclerosis, can result in a range of neurological and cognitive symptoms.

In conclusion, the Cerebrum, particularly the Cerebral Cortex, is a complex and intricate structure with billions of neurons organized into functional areas. Understanding its anatomy and functions will play a crucial role in advancing our knowledge of the brain and its underlying mechanisms, including the role of the gyrus and sulcus in the folding of the Cortex.