In short normal cellular constituents of brain and CNS and described. Reaction of neurons to injury like red neuron, axonal reaction, cerebral edema, intracranial hemorrhage, cerebrovascular diseases, vascular malformations including AV malformation, cavernous angiopathy, capillary telangiectesias and common degenerative diseases like Alzheimer disease, Parkinsonism, their etiopathogenesis, risk factors, clinical presentation and diagnosis are described too. Developmental anomalies like spina bifida, meningomyelocele, meningocele and hydrocephalus are mentioned with causes, types, clinical presentation and diagnosis. Inflammation of brain and meninges with their cause, clinical features, biochemical changes in CSF and laboratory diagnosis are mentioned. Common benign tumors of meninges- meningioma and malignant tumor gliomas are described in details with their risk factors, etiopathology, clinical manifestations, complications, types, and diagnostic modalities.