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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    articular coverings for the ends of the bones. It is also found existing transitorily in the process of osteo-genesis. The Osseous tissue constitutes the skeleton, and, with some modification, the ivory of the teeth or dentine. The Petrous tissue presents the extreme of departure from the animal organization, consisting almost entirely of crystals, which are chiefly com- posed of phosphate of lime. It is found in the enamel of the teeth, in the otoconites, and in the concretions of the pineal gland. The Muscular fibrous tissue constitutes the apparatus of motion, and is divided into two distinct varieties,—striped, or the muscular fibre of ani- mal life ; and unstriped, or the muscular fibre of organic life :—the former acting in obedience to the will, and the latter being wholly independent of it. The Nerve fibre is the conducting portion of the nervous system, and is like the muscular compound, being formed of two distinct substances, the one containing and the other contained. The Binary tissues are merely the intermixture or co-existence of two elementary tissues, the proportions of which vary according to the exigen- cies of the part of the body in which they are found. The grey or vesicular nervous matter consists of secreting cells, which disappear and are reproduced. Adipose tissue consists also of secreting cells, which retain their con- tents under certain circumstances for a great length of time, while under others they rapidly disappear. The vascular, mucous, and serous tissues of older writers, consist of aggregations of areolar, muscular, and epithelial tissues, variously modified. l.PROPERTIES OF THE TISSUES. The Chemical Properties have been given in the early portion of this chapter. PHYSICAL PROPERTIES OF THE TISSUES. The tissues, like other forms of matter, possess certain physical proper- ties, such as colour, consistency, and density, which it is necessary to describe under their respective heads. One property, however, is enjoyed by every tissue, and this seems to play a most important part in the main- tenance of the functions of life. I allude to the transudation of the solids by the fluids, which is known by the title of end osmosis and exosmosis, names by which the process was designated by Dutrochet, its discoverer. All the tissues contain a certain quantity of water, and in some cases this amounts to four-fifths of their weight, as may be proved by drying them ; and this water is essential, not only to their vitality, but confers upon them their organic properties—pliability and elasticity. As the tissues imbibe water in certain quantity, it becomes a subject of study to discover the manner by which the quantity may be increased. It is well understood how pressure from without would produce this effect, but even this would be aided by the natural tendency to imbibe and retain an additional quan- tity of water under favourable circumstances, which is strongly exhibited by the softer tissues. Such a tissue saturated with water placed in contact with another tissue or a fluid having a higher affinity for water than it has, will part with its superabundance, and if not supplied from behind will