The ox : its external and internal structures / by A. Seyfferth ; revised and edited by G.T. Brown.

  • Seyfferth, A.
Date:
[between 1900 and 1909?]
Catalogue details

Licence: In copyright

Credit: The ox : its external and internal structures / by A. Seyfferth ; revised and edited by G.T. Brown. Source: Wellcome Collection.

    22/36 (page 18)
    the lymph collecting in the spaces of the tissue, and in larger superficial or deep-seated branch-vessels; finally, however, in two principal branches, move towards the right and left auxiliary veins. The first chief branch is known as the lacteal duct, the second as the right bronchial root. All the lymphatic vessels, before they discharge in one of the chief branches of the vascular system, must pass through one or more lymphatic glands, an exceedingly large number of which are attached to fixed parts of the body. There is a difference between the “ pure lymph,” which resembles blood in its consistency, and lymph formed by the action of the glands of the stomach and intestinal canal during the process of digestion, which is known as milky fluid (chyle). The fluid, taken up by the lymph and chyle vessels, serves to thin the blood ; and, on the other hand, alters the composition of it. Animals with whom the contents of the lacteal duct was drawn off for a few days, lost considerably in weight, and nearly died. THE RESPIRATORY SYSTEM. In the respiratory organs, the change of gases occurs between the blood of the animals on the one hand and the atmospheric air, in which the animals must live, and only can live, on the other hand. The change of gas consists in this : the carbonic acid gas accumulated in the blood is discharged, and the oxygen necessary to life is conducted into the lungs, when the exchange takes place. Respiration is effected by means of the movable walls of the pectoral cavity, which, through more or less regular contraction and expansion of the muscles of breathing, cause expiration and inspiration. The air- tubes lead to the lungs. To the air-passages belong the nasal cavities, with the nasal openings, the cavities of the mouth, throat, larynx, and the air-tubes and their extensions. There are two nasal cavities, divided by the cartilaginous bridge of the nose, and in the middle and upper portions filled out by the ethmoid muscles, fine plates of bone, twisted many times about each other and covered with mucous membrane, the principal use of which is to prevent the entrance further into the air-passages of solid particles of dust and foreign bodies, and by means of their numerous blood-vessels to warm the inhaled air. Through the cavities of the mouth and throat, the inhaled air gets to the larynx. This lies between the branches of the lower jaw, forms the foundation of the laryngeal cavity and the com- mencement of the windpipe. Its foundation is composed of five movable, interwoven cartilages, the thyroid or scutiform cartilage, the annular or cricoid cartilage, the arytenoid and the epiglottis. Muscles and ligaments unite the epiglottis with its surroundings, particularly with the hyoid bone. The glottis is formed by two folds of mucous membrane in the inside of the larynx, which folds contain the vocal cords. The windpipe is a tube, formed by a row of about 50 rings of cartilage, open towards the back, which begins at the annular cartilage of the larynx, passes down into the pectoral cavity on the front part of the neck, and in front of the spinal column, enters between the two first ribs, and ends at the lungs in three larger branches (bronchi). The lungs, a pair of organs, are divided into right and left lung, which completely fill the space left vacant by the heart, larger blood-vessels, windpipe and oesophagus, and participates in every way with their move- ments and changes. They are soft, elastic organs, dark red in colour during life, and of a pale red in animals whose blood has been drained off; having a smooth outer surface, covered with the pleura, which appear correspondingly on the pulmonary lobes. The left lung is divided into two or three lobes, the right lung into three or four; among the latter y is reckoned the so-called middle lobe. The branches of the windpipe, as they pass on from the windpipe into the lungs, divide into the substance of the latter, becoming continually smaller until the finest end at last in little blind cells, lying close together like a bunch of grapes. These little bags, air-cells, are surrounded on the outer surface by an exceedingly fine capillary net, which, originating in the network of vessels of the pulmonary artery, supplies itself with venous blood, containing carbonic acid gas. Thus in the lung-cells takes place the change of gases used by the blood, the carbonic acid gas being, as already stated, given off