The general structural organization of the mature central nervous system is surveyed in Chapter 1. This chapter also introduces neuroanatomical nomenclature and fundamental histological and imaging techniques for studying brain structure and function. The three-dimensional shapes of key deep structures are also considered in this chapter. The functional organization of the central nervous system is introduced in Chapter 2. This chapter considers how different neural circuits, spanning the entire central nervous system, serve particular functions. The circuits for touch perception and voluntary movement control are used as examples. The major neurotransmitter systems are also discussed.
Central nervous system vasculature and cerebrospinal fluid are the topics of Chapter 3. By considering vasculature early in the book, the reader can better understand why particular functions can become profoundly disturbed when brain regions are deprived of nourishment. These three chapters are intended to provide a synthesis of the basic concepts of the structure of the central nervous system and its functional architecture. A fundamental neuroanatomical vocabulary is also established in these chapters.
The remaining 13 chapters examine the major functional neural systems: sensory, motor, and integrative. These chapters reexamine the views of the surface and internal structures of the central nervous system presented in the introductory chapters, but now from the perspective of the different functional neural systems. As these latter chapters on functional brain architecture unfold, the reader gradually builds a neuroanatomical knowledge of the regional and functional organization of the spinal cord and brain, one system at a time.
These chapters on neural systems have a different organization from that of the introductory chapters: Each is divided into two parts, functional and regional neuroanatomy. The initial part, on functional neuroanatomy, considers how the brain regions that comprise the particular neural system work together to produce their intended functions. This part of the chapter presents an overall view of function in relation to structure before considering the detailed anatomical organization of the neural system. Together with descriptions of the functions of the various components, diagrams illustrate each system’s anatomical organization, including key connections that help to show how the particular system accomplishes its tasks. Neural circuits that run through various divisions of the brain are depicted in a standardized format: Representations of myelin-stained sections through selected levels of the spinal cord and brain stem are presented with the neural circuit superimposed.
Regional neuroanatomy is emphasized in the latter part of the chapter. Here, structures are depicted on myelin-stained histological sections through the brain, as well as magnetic resonance images (MRIs). These sections reveal the locations of major pathways and neuronal integrative regions. Typically, this part examines a sequence of myelin-stained sections ordered according to the flow of information processing in the system. For example, coverage of regional anatomy of the auditory system begins with the ear, where sounds are received and initially processed, and ends with the cerebral cortex, where our perceptions are formulated. In keeping with the overall theme of the book, the relation between the structure and the function of discrete brain regions is emphasized.
Emphasis is placed on the close relationship between neuroanatomy and neuroradiology especially through use of MRI scans. These scans are intended to facilitate the transition from learning the actual structure of the brain, as revealed by histological sections, to that which is depicted on radiological images. This is important in learning to “read” the scans, an important clinical skill. MRI scans are presented either using the radiological convention of showing the ventral surface of the brain up or, when the focus is learning detailed regional anatomy, showing the ventral surface down together with corresponding myelin-stained sections. It should be recognized that there is no substitute for actual stained brain sections for developing an understanding of regional anatomy and localization of function. This is because current MRI resolution is not sufficient to reveal the breadth of brain and spinal cord structures whose functions need to be considered.