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REGIONAL ANATOMY.

By M. H. CRYER, M. D., D. D. S.

BONES.

Bones belong to one of the three groups of connective tissue, fibro-
conneetive, cartilage, and bone connective tissue. Each of these divis-
ions may be again subdivided into several minor divisions; but under
all circumstances the ground substance, or matrix, or intercellular sub-
stance of each is distinguished by the cells peculiar to it. The matrix
of fibro-connective tissue yields gluten or gelatin, that of cartilage
connective tissue yields chondrin, and that of bone connective tissue
yields the salts of calcium. With the single exception of the teeth,
bone is the hardest, heaviest, and most solid structure of the body:
it forms the framework of the body, keeps the parts in position, and
acts as lever and fulcrum; its grooves act as pulleys through which
glide the tendons of certain muscles ; it protects vital parts, such as
the brain and spinal cord, from injury; it also, in great measure,
gives character and individuality of expression to the head and body
generally.
Bones are derived from the two great kingdoms of nature—the
organic and inorganic.
The principal portions of the several bones, such as the shafts of
long bones, are called the diaphyses ; and the smaller parts, such as the
ends of long bones, their epiphyses, the term apophyses being a])])lied
to those nodules on bones which are not formed from separate points of
ossification.
If a long bone be cut longitudinally (Fig. 1), it is seen to be made
up of an outer and an inner layer ; the outer being called the compact,
the inner the spongy or cancellated, portion.
Note.—The writer claims no originality for the purely descriptive matter herein
contained. In its preparation notes of the lectures of Professors Allen, Garretson,
Stelhvagen, and Leidy have been of great value, and the following works have been
consulted and freely drawn from : Gray's, Allen's, Quain's, and Leidy's works on
Human Anaioimi ; Treves's Applied Anatomy ; Bell's Anatomi/ of Exprrmon ; Allen's
Facial Region ; Tomes's Dental Anatomy ; Garretson's Si/stem. of Oral Surf/eri/ ; Parker
and Bessang's Morphology of the Skull ; Klein's Elements of Histology ; p'lint's Pliyxiologg
and Diseases of the Xerrous System; Cole's Studies in Microscopical Science; Prudden's
Practical Histology ; and Duhring on Diseases of the Skin.
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