A system of human anatomy, general and special / by Erasmus Wilson.

  • Wilson, Erasmus, Sir, 1809-1884.
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: A system of human anatomy, general and special / by Erasmus Wilson. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    CHAPTER II. OSTEOLOGY. The bones are the organs of support to the animal frame; they give firmness and strength to the entire fabric, afford points of connection to the numerous muscles, and bestow individual character upon the body. In the limbs they are hollow cylinders, admirably calculated by their con- formation and structure to resist violence and support weight. In the trunk and head, they are flattened and arched, to protect cavities and provide an extensive surface for attachment. In some situations they present projections of variable length, which serve as levers ; and in others are grooved into smooth surfaces, which act as pulleys for the passage of tendons. Moreover, besides supplying strength and solidity, they are equally adapted, by their numerous divisions and mutual apposition, to fulfil every movement which may tend to the preservation of the creature, or be conducive to his welfare. According to the latest analysis by Berzelius, bone is composed of about one-third of animal substance, which is almost completely reducible to gelatine by boiling, and of two-thirds of earthy and alkaline salts. The special constituents of bone are present in the following proportions:— Cartilage 3217 parts. Blood-vessels 1'13 Phosphate of lime 51*04 Carbonate of lime 11-30 Fluate of lime 2-00 Phosphate of magnesia 116 Soda, chloride of sodium 120 100-00 Bones are divisible into three classes:—Long,flat, and irregular. The Long bones are found principally in the limbs, and consist of a shaft and two extremities. The shaft is cylindrical or prismoid in form, dense and hard in texture, and hollowed in the interior into a medullary canal. The extremities are broad and expanded, to articulate with ad- joining bones ; and cellular or cancellous in internal structure. Upon the exterior of the bone are processes and rough surfaces for the attachment of muscles, and foramina for the transmission of vessels and nerves. The character of long bones is, therefore, their general type of structure and their divisibility into a central portion and extremities, and not so much their length ; for there are some long bones, as the second phalanges of the toes,&which are less than a quarter of an inch in length, and almost equal, and in some instances exceed, in breadth their longitudinal axis. The long bones are, the clavicle, humerus, radius and ulna, femur, tibia and fibula, metacarpal bones, metatarsal, phalanges, and ribs. Flat bones are composed of two layers of dense bone with an interme- diate cellular structure, and are divisible into surfaces, borders, angles, and processes. They are adapted to inclose cavities; have processes upon their surface for the attachment of muscles; and are perforated by foramina, for the passage of nutrient vessels to their cells, and for the transmission