The Adult Central Nervous System: Anatomy and Physiology
The human brain consists of three basic subdivisions – the cerebral hemispheres, the brain stem, and the cerebellum. Speech is represented by two main areas – Broca’s area in the inferior frontal lobe (expressive speech) and the Wernicke’s area in the temporoparietal cortex (interpretation of language) (Fig. 1.1). Language localization is found in 96% of population in the left. The basal ganglia are a collection of nuclei deep in the white matter of the cerebral cortex and contain the substantia nigra. A decrease in function of the dopaminergic neurons located in the substantia nigra causes Parkinson’s disease. The cerebral hemispheres are connected together medially by the corpus callosum. The limbic areas of the brain include the hypothalamus, amygdala, hippocampus, and limbic cortex. Optic nerve (second) leaves the retina of the eye and travels to the optic chiasm, located just below and in front of the pituitary gland. In the optic chiasm, the optic nerve fibers arising from the nasal half of each retina cross over to the other side; but the nerve fibers originating in the temporal retina do not cross over.
KeywordsCircle of Willis Cerebral hemispheres Brain stem Cranial nerves Somatosensory pathways Cerebrospinal fluid
- Bendo AA, Kass IS, Hartung J, Cottrell JE. Anesthesia for neurosurgery. In: Barash PG, Cullen BF, Stoelting RK, editors. Clinical anesthesia. 5th ed. Philadelphia: Lippincott Williams & Wilkins; 2006. p. 746–89.Google Scholar
- Cottrell JE, Smith DS. Anesthesia and neurosurgery. 4th ed. St Louis: Mosby; 2001.Google Scholar
- Drummond JC, Patel PM. Neurosurgical anesthesia. In: Miller’s anesthesia. 6th ed. Philadelphia: Elsevier, Churchill Livingstone; 2005. p. 2127–73.Google Scholar
- Newfield P, Cottrell JE, editors. Handbook of neuroanesthesia. 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2006.Google Scholar
- Patel PM, Drummond JC. Cerebral physiology and effects of anesthetics and techniques. In: Miller’s anesthesia. 6th ed. Philadelphia: Elsevier, Churchill Livingstone; 2005. p. 813–57.Google Scholar