The outer layers of the cerebrum are made up of grey matter. Grey matter is formed by neurons and their unmyelinated fibres. The white matter below the grey matter of the cortex is formed predominantly by myelinated axons (myelin is white in appearance). The surface of the cerebral cortex is folded; more than two thirds of the surface is within the grooves or ''"sulci"''. The cerebral cortex is connected to structures such as the thalamus and the basal ganglia, sending information to them along ''efferent'' connections and receiving information from them via ''afferent'' connections. Most sensory information is routed to the cerebral cortex via the thalamus. The cortex is commonly described as comprising three parts; sensory, motor and association areas. | The outer layers of the cerebrum are made up of grey matter. Grey matter is formed by neurons and their unmyelinated fibres. The white matter below the grey matter of the cortex is formed predominantly by myelinated axons (myelin is white in appearance). The surface of the cerebral cortex is folded; more than two thirds of the surface is within the grooves or ''"sulci"''. The cerebral cortex is connected to structures such as the thalamus and the basal ganglia, sending information to them along ''efferent'' connections and receiving information from them via ''afferent'' connections. Most sensory information is routed to the cerebral cortex via the thalamus. The cortex is commonly described as comprising three parts; sensory, motor and association areas. |