The Creation of God

by Jacob Hartmann

The general effect of digestion of the stomach is the conversion of food into chyme, a substance of various compositions according to the nature of the food, yet always presenting a characteristic thick pultaceous grumous consistence.

The small intestines commence at the pylorus and after many convolutions terminate in the large intestines. They measure on an average about twenty feet in length in the adult. For convenience they have been divided into three parts—the duodenum, which extends from eight to ten inches beyond the pylorus; the jejunum, which occupies two-fifths, and the ilium, which occupies three-fifths, of the rest of the canal.

The mucous membrane, the interior coat, is the most important to the function of digestion. There are permanent folds, shelf-like processes, of the mucous membrane, called valvular conniventes. There are also villi and glands, as the glands of Lieberkühn, of Peyer, and of Bruner. The glands of Lieberkühn are thickly distributed over the whole surface of the large and small intestines. The glands of Peyer are exclusively in the small intestine. They are found in greatest abundance in the lower part of the ileum near to the ileo-cæcal valve. They are met with in two conditions, viz., either scattered singly, in which case they are termed glandulæ solitairæ, or aggregated in groups varying from one to three inches in length and about half an inch in width, chiefly of an oval form, their long axes parallel with that of the intestines. In this state they are named glandulæ agminatæ. The latter are almost always placed opposite the attachment of the mesentery. In structure they are analogous to lymphatics or absorbent glands, and their office is to take up certain materials from the chyle, elaborate them, and subsequently discharge them into the lacteals, with which vessels they appear to be closely connected. Bruner’s glands are confined to the duodenum; they are most abundant and thickly set at the commencement of this portion of the intestines, and are provided with permanent gland ducts.

The villi are confined exclusively to the mucous membrane of the small intestines. They are minute vascular processes, from a quarter of a line to a line and two-thirds in length. There are about fifty to ninety in number to a square line. Each villus consists of a small projection of mucous membrane, and its interior is supported throughout by fine retiform or adenoid tissue. Two or more arteries are distributed to each villus, and from their capillaries, which form a dense network, proceed one or two small veins, which pass out at the base of the villus.

The lacteal vessels enter the base of each villus, and passing up in the middle extend nearly to the top, where it ends commonly by a closed and somewhat dilated extremity. The office of the villi is the absorption of chyle from the completely digested food of the intestines.

The large intestine extends from the termination of the ileum to the anus. It is usually about five to six feet in length, being about one-fifth of the whole length of the intestinal canal. The large intestine is constructed of four coats like those of the stomach and small intestines, namely, the serous, the muscular, the areolar or submucous, and the mucous. It is divided into the ascending colon, transverse and descending colon, and rectum and anus.

The cæcum is a short wide pouch, communicating with the lower end of the small intestines through an opening guarded by the ileo-cæcal valve. The appendix vermiformis is attached to the cæcum. The colon commences at the right groin, ascends to the liver, forms the hepatic flexure, then crosses transversely from right to left to the spleen, forms the splenic flexure, descends to the left groin, forms the sigmoid flexure, passes through the pelvis as the rectum, and terminates at the anus.

The mucous membrane of the large intestines, like that of the small intestines, is lined throughout by columnar epithelium, but unlike it, is quite destitute of villi and is not projected in the form of valvular conniventes.

The peritoneum, or serous membrane of the abdominal cavity, is by far the most extensive and complicated of serous membranes. Like the others, it may be considered to form a shut sac, on the outside of which are placed the viscera, which it covers. The peritoneum forms the mesenteries and omenta for the stomach, small and large intestines, and ligaments for the liver, spleen, uterus, and bladder.

The liver is a very important glandular organ, very constant in the animal series, being found in all the vertebrates, and, in a more or less developed condition, in most invertebrate tribes. It secretes bile, and appears to act upon the blood which is transmitted through it. The liver is the largest gland in the body, and by far the most bulky of the abdominal viscera. It measures from ten to twelve inches transversely from right to left, between six and seven inches from its posterior to its anterior border, and about three and a half inches from above downwards where thickest, which is towards the right and posterior part. The average bulk is about eighty-eight cubic inches. The ordinary weight in the adult is between 50 to 60 ounces, about one-thirtieth of the weight of the whole body. The liver is solid to the feel, and of a dull reddish-brown color, with frequently a dark-purplish tinge along the margin. It has an upper surface smooth and convex, and an under surface which is uneven and concave. The liver is divided into two unequal lobes, a right and a left, and on the under surface of the right lobe are three secondary lobes or lobules, named the lobe of Spigolius, the caudate or tailed lobe, and the square lobe. It has five fissures or fossæ, described as the transverse or portal; the umbilical fissure and the fissure of the ductus venosus, together forming the longitudinal fissure; the fossa of the vena cava, and the fossa of the gall bladder. It is held in position by five ligaments formed by layers of peritoneum.