Henry Gray (18251861). Anatomy of the Human Body. 1918.
THE TERM human anatomy comprises a consideration of the various structures which make up the human organism. In a restricted sense it deals merely with the parts which form the fully developed individual and which can be rendered evident to the naked eye by various methods of dissection. Regarded from such a standpoint it may be studied by two methods: (1) the various structures may be separately consideredsystematic anatomy; or (2) the organs and tissues may be studied in relation to one anothertopographical or regional anatomy.
It is, however, of much advantage to add to the facts ascertained by naked-eye dissection those obtained by the use of the microscope. This introduces two fields of investigation, viz., the study of the minute structure of the various component parts of the bodyhistologyand the study of the human organism in its immature condition, i. e., the various stages of its intrauterine development from the fertilized ovum up to the period when it assumes an independent existenceembryology. Owing to the difficulty of obtaining material illustrating all the stages of this early development, gaps must be filled up by observations on the development of lower formscomparative embryology, or by a consideration of adult forms in the line of human ancestrycomparative anatomy. The direct application of the facts of human anatomy to the various pathological conditions which may occur constitutes the subject of applied anatomy. Finally, the appreciation of structures on or immediately underlying the surface of the body is frequently made the subject of special studysurface anatomy.
SYSTEMATIC ANATOMY.The various systems of which the human body is composed are grouped under the following headings:
Osteologythe bony system or skeleton.
Syndesmologythe articulations or joints.
Myologythe muscles. With the description of the muscles it is convenient to include that of the fasciæ which are so intimately connected with them.
Angiologythe vascular system, comprising the heart, bloodvessels, lymphatic vessels, and lymph glands.
Neurologythe nervous system. The organs of sense may be included in this system.
Splanchnologythe visceral system. Topographically the viscera form two groups, viz., the thoracic viscera and the abdomino-pelvic viscera. The heart, a thoracic viscus, is best considered with the vascular system. The res