Horses and stables / [Frederick Wellington John Fitzwygram].

  • Fitzwygram, Frederick, Sir, 1823-1904.
Date:
1881
Catalogue details

Licence: Public Domain Mark

Credit: Horses and stables / [Frederick Wellington John Fitzwygram]. Source: Wellcome Collection.

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    chapter, to enter into any minute descriptions of structures or processes; but an endeavour will be made to give concisely, and it is hoped sufficiently, broad principles and facts which may enable the non-professional reader to understand the subject referred to. 2. Circulation of the blood. By each contraction or beat of the heart bright scarlet highly vitalized blood fresh from the lungs is forced through the arteries to all parts of the body. The arteries dividing and sub- dividing become smaller and smaller, and ultimately terminate in very minute hair-like tubes, called capillary vessels or capillaries. These vessels abound in every vascular structure, and from them each structure absorbs those special nutrient particles which are required for its growth or repair. In the capillaries the arterial or outward-bound system of the circula- tion ends. In these same capillaries the venous or return circulation commences. Into them also are returned the waste and used up products of the system. Reversing the previous order the capillaries now enlarge and coalesce and open into the veins, which carry back to the heart dark, purple, venous blood, charged with the waste matters of the tissues, and among these with carbonic acid gas. The impure blood thus brought back by the veins is carried to the right side of the heart, and thence at each contraction or beat of that organ is forced into the lungs. The lungs contain an infinite number of cells, 'which through the bronchise and windpipe communicate with the outer air. On the outside of these cells the blood-vessels are spread. The blood thus exposed to the air takes up from it a portion of its oxygen, and gives off the carbonic acid gas and various volatile organic matters which have accumulated in it, as described above. Thus freed from impurity, and containing more oxygen, the blood again becomes bright scarlet and adapted for the nutrition of the body; and in this state it is returned to the left side of the heart for renewed circulation through the frame. From birth to death this process is always going on.