The principles and practice of the botanic system of medicine : a guide to the understanding of the nature of disease, its prevention and cure, by the use of simple, safe, and sanative means / by W. Dale.

  • Dale, W.
Date:
1855
Catalogue details

Licence: Public Domain Mark

Credit: The principles and practice of the botanic system of medicine : a guide to the understanding of the nature of disease, its prevention and cure, by the use of simple, safe, and sanative means / by W. Dale. Source: Wellcome Collection.

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    capillaries, which convey it to, fifth, the veins, which return it as purple blood, running near to the surface of the body, to the heart. The heart is naturally separated by a partition into two parts, right red, and left blue; each part has two apartments, an ante- room, or auricle, and an audience chamber, or ventricle; the auricles have communication with the ventricles by trap-doors or valves, on the right, three-pointed (tricuspid), on the left, two-pointed (bicuspid). When a portion of the blood has passed from the auricles, the upper apartments, into the ventricles, the lower, these valves close till the ventricles have passed that portion into the arteries which convey it from them; at the mouths of the arteries leading from the heart are also placed valves, but closing the other way3 shutting the blood in the arteries, and preventing its return to the ventricles. Each side of the heart has attached to it a set of veins and a set of arteries; from the lungs come veins tilled with red blood, to the right side of the heart; and from this side of the heart go arteries filled with red blood to all parts of the body; from all parts of the body come blue veins to the left side of the heart, and from this side of the heart go arteries filled with blue blood to the lungs; the great blue artery going from the left side of the heart to the lungs is called the pulmonary artery, and the great red vein coming from the lungs to the right side of the heart is called the pulmonary vein. The valves placed at the mouths of the arteries are called semi-lunar (half-moon-like) valves. It is said by physiologists of the present day, that the office filled by the heart, with its accurately-working valves, is essentially that of a forcing-pump: that by the successive contractions of the ven- tricles, the blood is forced to go forward in the arteries to every part of the body, and that thirteen thousand pounds of blood are forced out of the left ventricle of the heart of an ordinary-sized man every twenty-four hours. The quantity of arterial blood pro- pelled from the left ventricle of the heart at each contraction, is from one to two ounces. The arteries leading from the heart to all parts of the body, almost immediately they leave the heart, divide into branches, gradually diminish in capacity, and increase in number; so that if the circulation of the blood be effected solely by the mechanical force of the heart, the force it exerts must be considerable, since the force requisite to propel a quantity of blood through thousands, tens of thousands, perhaps millions of tubes, gradually diminishing in size, from the first, less than an inch in