Part 59

V. Particular Phenomena of the Development of the Sesamoid Bones.

General arrangement of the sesamoid bones.—Situation.—Forms. 221

Fibro-cartilaginous state.—Osseous state.—Phenomena of the patella.—Use of the sesamoid bones. 222

MEDULLARY SYSTEM.

Division of this system. 225

ARTICLE FIRST.

MEDULLARY SYSTEM OF THE FLAT AND SHORT BONES, AND THE EXTREMITIES OF THE LONG ONES.

I. Origin and Conformation.

It is an expansion of the vessels of the second order. 225

II. Organization.

There is no medullary membrane.—Vascular interlacing. 226

III. Properties.

There are only organic ones.—Experiments. 227

IV. Development.

There is no medullary oil in infancy.—Proofs.—Experiments. 227

ARTICLE SECOND.

MEDULLARY SYSTEM OF THE MIDDLE OF THE LONG BONES.

I. Conformation.

It is like the cellular. 229

II. Organization.

The medullary membrane is not an expansion of the periosteum.—Its vessels. 230

III. Properties.

Properties of texture.—Vital properties.—Animal sensibility.—Vitality more active than in the bones. 231

IV. Development.

How the medullary membrane is formed.—The marrow of the infant is wholly different from that of the adult.—Proofs. 233

Functions.—The marrow is exhaled.—Its alterations.—Its relations with the nutrition of the bone.—Necrosis.—The marrow is foreign to the synovia. 234

CARTILAGINOUS SYSTEM.

What must be understood by cartilage. 237