ABSTRACT
This chapter describes the brain’s global architecture and subdivisions, starting with the phylogenetically newer neuroanatomical systems and their evolution, and working down to older systems and their component structures, nuclei and circuits. The term ‘cerebral cortex’ or ‘neocortex’ refers to the part of the forebrain that developed late in the phylogeny. Myelin is a sheet of fatty substance that is wrapped around the axons and is found in the brain as well as in the peripheral nervous system. Neurons vary in shape depending on their functional role as sensory, motor, pyramidal neuron or local interneuron. The brain contains a series of interconnected chambers called ventricles that are filled with cerebrospinal fluid. The fluid is manufactured by the choroid plexus, a tissue with a rich blood supply. The human brain is an amazingly complex system that evolved from natural selection and successive adaptations during the long course of evolution.
