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.

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    muscular sheath, are somewhat thicker than those of the small intestine. Like this latter, it has oblique folds of mucous membrane, and has strings on its outer surface. The colon has a smooth exterior, and its mucous membrane small oblique folds. The rectum passes to the back under the spinal column, and terminates in the anus, which, closing by means of constrictor muscles, prevents the involuntary evacuation of the contents of the bowels. Both the stomachs and intestinal canal are in a great measure kept in place by the organs formed by the folding over of the peritoneum, by the plexus and mesentery, in such a way that the freedom of movement in the intestinal tube, the so-called peristaltic movement, is not hindered. In fat animals, large masses of fat lie round the plexus (omentum 1 epiploon ?) and mesentery. The length of the whole intestinal tube varies very much. While the small intestine has a length of from 36 to 45 metres, according to the size of the full-grown animal, the length of the great intestine is limited to from 9 to 11 metres. Two already named large glandular organs, the liver and the pancreas, play an important part in digestion. The first, lying im- mediately behind the diaphragm, secretes the bile, which is conveyed through the biliary gall-duct to the duodenum ; the latter furnishes the pancreatic fluid, which also goes into the duodenum through the pancreatic duct. The bile assists materially in the absorption of fat; it also exercises a certain antiseptic' action, while the pancreatic fluid continues the fermentative action set up by the saliva. The liver is a large reddish-brown gland, rectangular in shape, somewhat concave towards the front, and slightly flattened at the back. It is held by several ligaments to the diaphragm, and divided into two halves by fissures. On the posterior surface of the liver, near the lower part, is seen the reservoir for the gall and the gall-bladder; the biliary duct leads from it; and this, in its subsequent union with the hepatic duct, forms the common biliary duct, which conveys the bile into the duodenum. By means of the secretions of the above-mentioned gland of the mucous membrane of the intestinal canal, and also through the mingling OX. 21 of the secretions of the liver and pancreas, all solid elements of food become dissolved during their passage through the intestinal tube, and made fit for absorption—so that, in the last portion of the rectum, the excrement (faeces) alone collects, which is cast forth in more or less distinctly-shaped balls. The spleen has nothing directly to do with the digestion; but it is necessary to mention it, as it lies directly on the left side of the paunch, and is attached to it. Its functions are not well understood ; but most probably these are more concerned with the circulatory than the digestive system. URINARY SYSTEM. Urinary organs.—The urinary organs comprise the kidneys, which separate the urine from the blood ; the ureters, which convey it to the bladder; and the urethra, to carry it from the body. There are two kidneys, each formed of many lobes, and are secretory glands, oval in shape, brownish-red in colour, and of rather a firm consistency. They lie outside the peritoneum in the abdominal cavity, in the region of the fore part of the upper loins, right and left of the spinal column. In dissecting the kidneys, a cortex and marrow substance are distinguished clearly, to the number of from 15 to 18, even to 30 renal lobes in each kidney. In addition to a peculiar, web-like, detachable membrane, the kidneys are enveloped and kept in place by a strong fibrous membrane and masses of fat. In front of the kidneys lie the renal capsules. The urine, secreted in the so-called Malpighian bodies and uriniferous tubes, collects in the pelvis of the kidney, and is conveyed through the ureters (two fine membranous tubes, which form the immediate continuation of the kidney-pelvis) into the bladder, a somewhat elongated, round membranous receptive organ. Here it collects, and is retained by the sphincter muscle of the bladder until discharged—in male animals through the urethra contained within the penis; in the female it is discharged through the vagina.