The cerebrum is the largest brain region, responsible for thought, memory, sensation, voluntary movement, and emotion.
The cerebrum is the largest and most prominent part of the human brain, occupying the uppermost region of the cranial cavity. It is responsible for a wide range of complex functions including voluntary motor activity, sensory perception, speech, reasoning, learning, memory, and emotional regulation. It is divided into left and right hemispheres and is highly convoluted to maximize cortical surface area.
The cerebrum is composed of two hemispheres — left and right — connected by a thick band of white matter called the corpus callosum. Each hemisphere is further divided into four lobes: frontal, parietal, temporal, and occipital. The surface of the cerebrum is characterized by ridges called gyri and grooves called sulci. Deep grooves, such as the longitudinal fissure and lateral sulcus, demarcate major divisions between lobes and hemispheres.
The cerebrum is located in the supratentorial compartment of the cranial cavity, above the tentorium cerebelli. It overlays the diencephalon and brainstem and fills most of the cranial vault. The central sulcus separates the frontal lobe from the parietal lobe, while the lateral sulcus separates the frontal and parietal lobes from the temporal lobe.
The left and right cerebral hemispheres are structurally similar but functionally specialized. In most right-handed individuals, the left hemisphere is dominant for language, logic, and analytical tasks, while the right hemisphere is more involved in spatial awareness, creativity, and holistic processing. The hemispheres communicate via commissural fibers, primarily through the corpus callosum.
The cerebrum governs higher cognitive functions and integrates input from various sensory modalities to generate appropriate responses. Major functional domains include:
The cerebrum receives its blood supply from three main pairs of cerebral arteries:
These arteries are branches of the internal carotid and vertebral-basilar systems and are connected via the Circle of Willis.
Venous blood from the cerebrum drains into the dural venous sinuses via superficial and deep cerebral veins. Major sinuses include the superior sagittal sinus, straight sinus, and transverse sinuses, which ultimately drain into the internal jugular veins.
The cerebrum develops from the telencephalon, the anterior-most part of the embryonic forebrain. By the fifth gestational week, the telencephalic vesicles expand and differentiate. Neuronal migration and cortical folding begin by mid-gestation and continue postnatally. The cerebral cortex becomes increasingly convoluted, forming gyri and sulci that allow for greater surface area and functional complexity.
The cerebral cortex is made up of six distinct layers of neurons (in most areas), known as the neocortex. These layers include pyramidal cells, interneurons, and glial cells. The white matter beneath contains bundles of myelinated axons organized as projection fibers (to/from subcortical regions), commissural fibers (between hemispheres), and association fibers (within a hemisphere).