CHAPTER 2 Neuroanatomy by Dissection
The neuroanatomic components of this textbook are based on and complement the dissection of the nervous system described in Guide to the Dissection of the Dog by H. E. Evans and A. de Lahunta (ed 6, Philadelphia, 2004, Elsevier). The peripheral nerves are described and dissected along with the regions of the body in which they are found. The dissection of the brain and spinal cord is found in the last section, titled “Nervous System.” The split head of the embalmed dog used for the dissection of the entire dog is also used to demonstrate the blood vessels and meninges. A separate entire preserved dog brain is provided to each group of students for the dissection. The spinal cord can be dissected on the embalmed dogs or presented as prosections. On completion of the brain dissection, an additional preserved domestic animal brain is provided to each group for the study of the transverse sections.
In the Cornell curriculum this dissection is performed simultaneously with lectures and discussions of nervous system development, cerebrospinal fluid, and malformations, including hydrocephalus, which are the subjects of Chapters 3 and 4 of this book.
The nomenclature used in this third edition, as in Guide to the Dissection of the Dog, adheres to that published in the fifth edition of Nomina Anatomica Veterinaria in 2005, unless otherwise stated.
TRANSVERSE BRAIN SECTIONS
The following transverse brain sections in Figs. 2-2 through 2-17 are arranged from rostral to caudal through the brain at irregular intervals, as indicated on the drawings in Fig. 2-1. In these sections the white matter has been stained and appears black, whereas the gray matter is relatively unstained.
Figure 2-1 Dorsal and left lateral views of the brainstem, indicating the approximate levels of the following transverse sections.
Figs. 2-18 through 2-33 are transverse plane (axial) proton density MR images of a normal adult dog for comparison with Figs. 2-2 through 2-17. The images are 2 mm thick, but to select those that best demonstrate the anatomic features, the intervals between images vary.