It is a continuous tube from the mouth to the anus. It is distributed into various portions, named as follows: The mouth, pharynx, oesophagus, stomach, and intestines. The intestines are sub-divided into the small, which are distinguished as the duodenum, jejunum, and ileum; and the large, distinguished as caecum, colon, and rectum.HBH 160.6

335. What office does the mouth hold in the work of alimentation?HBH 160.7

It is in the mouth that the food is prepared to enter the stomach. It is furnished with teeth for grinding the food. Time should be taken in eating the food, to mash it finely with the teeth, for this greatly lightens the work of the stomach. The mouth, and not the stomach, is the mill; so let the grinding be done in the mouth. There are also connected with the mouth salivary glands. Of these there are three, called the parotid, sub-maxillary, and sub-lingual. The first of these, which is the largest, is situated just in front of the external ear. Its ducts communicate with the mouth near the second double tooth. The second pair of these glands lie just within the lower edge of the under jaw, on each side. The third and smallest pair lie under the roots of the tongue, uniting on the middle line of the tongue.HBH 160.8

336. What is the office of the salivary glands?HBH 161.1

They secrete the saliva or solvent fluid of the mouth, and pour it freely into the oral cavity during the process of mastication, and whenever any exciting substance is taken into the mouth. The smell, and sight, and even the thoughts, of savory or disgusting substances, will cause an increased secretion and flow of saliva. By the action of the saliva upon the food in the mouth, the food is not only prepared for swallowing, but the process of digestion is commenced. This work is performed to a greater or less extent according to the length of time the food is kept in the mouth. The process of chewing increases the flow of saliva. If the food is not properly masticated, the stomach is irritated, and all irritations of the stomach greatly affect the condition of the salivary glands, and the nature of their secretion.HBH 161.2

337. What injury is done to the stomach by improper mastication?HBH 161.3

A four-fold injury is done to the stomach: 1, It compels the stomach to receive the food more rapidly than is consistent with its welfare. 2, It compels the stomach to secrete a larger quantity of solvent fluid than would be necessary if the functions of the mouth had been properly performed.HBH 161.4

3, It compels the stomach, at great inconvenience, to reduce by maceration those masses which ought to have been broken down and finely ground by the teeth. 4, By increasing the duration and difficulty of gastric digestion, it increases the expenditure of the functional powers of the stomach, and thus causes a greater degree of vital exhaustion in that organ, tending to debility and disease.HBH 162.1

338. What are the properties of the gastric juice?HBH 162.2

The gastric juice is supposed to contain muriatic and acetic acids, phosphates and muriates of potassa, soda, magnesia, and lime. This composition, however, differs with the quality or kinds of food taken. The active principle of gastric juice is called pepsin, which has the power of exciting chemical changes in the particles of other substances without itself decomposing. But no pepsin prepared by a chemist can accomplish the effect produced in nature’s great laboratory.HBH 162.3

339. Does drinking with our food injure the action of the salivary glands?HBH 162.4

To drink cool, soft water while eating, if we are thirsty, is probably not injurious, if the mouth is cleared from food before we drink. Washing down our food with drink of any kind is injurious. The food should be moistened sufficiently to swallow with the saliva, for reasons before assigned.HBH 162.5

340. What are the tonsils, and what is their use?HBH 162.6

They are two almond-shaped bodies, situated in each side of the back part of the mouth. They are clusters of mucous glands. They pour out mucous and lubricate the food forced between them as it is being swallowed. The tonsils are liable to swell and become troublesome, being sore to the touch externally, and partly closing the passages within; in which case it is sometimes advisable to have them cut out by a skillful surgeon.HBH 162.7

341. What is the oesophagus?HBH 163.1

The oesophagus is the continuation of the alimentary canal from the pharynx to the stomach. It is sometimes called the meat-pipe. It is some twelve or fifteen inches in length. In its descending course along the spine, it inclines to the left in the neck, to the right in the upper part of the thorax, and to the left again as it passes through the back part of the diaphragm. It terminates at the stomach, and serves the office of conveying the food from the pharynx to the stomach.HBH 163.2

342. How is the food swallowed?HBH 163.3

When the food is prepared for swallowing, it is gathered back upon the arch of the tongue, whence it is suddenly launched into the pharynx, and passes through the meat-pipe to the stomach. The food, it will be remembered, in passing to the meat-pipe, passes over the glottis or top of the wind-pipe, as well as past the nasal cavities and eustachian tubes. These are all closed in the act of swallowing, that the food or drink may not pass into them. At the instant the food is launched from the arch of the tongue, the muscles of the pharynx contract, shortening the pharynx, and raising up the larynx; at the same instant the vail of the palate is pressed back, and closes the nasal canals and the tubes coming from the ears; the epiglottis shuts down and closes the glottis, and the pharynx darts up, and seizes the descending mass, and suddenly dropping down, presses it into the meat-pipe. As soon as the oesophagus receives the food, its muscular coat contracts upon it from above downward, and presses it onward into the stomach; and at the same time the mucous follicles, situated in this narrow passage, pour out their lubricating fluid to shield the nerves and vessels of the lining membrane, and to facilitate the movement of the descending mass. When the food has passed from the oesophagus, its lower portion continues to contract upon the stomach to prevent the food passing back during the action of the stomach.HBH 163.4

343. What is the stomach?HBH 164.1

The stomach is an expansion of the alimentary tube, its greater or splenic end being brought in contact with the concave surface of the spleen. The lesser or pyloric end extends into the epigastric region. Its opening into the oesophagus is from its upper side, and on account of its proximity to the heart, it is called the cardiac orifice. The inferior mouth of the stomach, which opens into the small intestine, is but a little lower than that at which the food enters. This opening from the stomach is called the pyloric orifice. The stomach is ordinarily capable of containing from one to two quarts. It may be enlarged by gluttony, or diminished in size by disease.HBH 164.2

344. How does the stomach act upon the food?HBH 164.3

As stated in the chapter on the muscular system, the stomach has muscles extending both ways; around it and lengthwise. When the food is felt by the nerves in the stomach, the muscular fibers are called into a rapid and vigorous action, the whole stomach is thrown into a gentle commotion, by which the food is carried around the gastric cavity, and everywhere pressed against the internal surface. This excites the glands, which secrete a thin, transparent fluid called gastric juice, which very soon begins, like sensible perspiration, to exude from the mucous membrane, in small drops, and mingle with the food. After the first portion of food has been carried about the gastric cavity, and freely mixed with this fluid, if the stomach be not crowded too fast with food, its muscles relax to some extent, and it is prepared to receive another portion of food, which undergoes the same process as the first. These operations are continued, until the stomach is distended with food, and the meal is finished. Then the muscular action is less rapid; a gentle, undulating motion takes place, and is kept up, till the function of the stomach is completed, and its contents poured through the pyloric orifice into the small intestine.HBH 164.4

345. What is the pyloric orifice?HBH 165.1

It is a thick band of muscular fibers, forming a powerful ring, which, together with a thickening or folding of the mucous membrane upon itself, forms what is called the valve of pylorus, or, more commonly called, the pylorus or “gate-keeper.” When this ring is contracted, the orifice is closed. Its office is to prevent the contents of the stomach from passing into the small intestine in a crude and undigested state; but when a portion of food has become prepared to pass from the stomach, it is carried along by the muscular action of the stomach to the pylorus, which, by a peculiar organic instinct, perceives its character and condition, and immediately opens and suffers it to pass into that portion of the small intestine called the duodenum. When the pylorus is in a healthy condition, if a crude mass of undigested food attempts to pass into the duodenum with the chyme, it immediately closes, forcing the matter back, to be subjected again to the action of the stomach. If the substance, after a few such efforts to pass, is discovered to be of an indigestible nature, the orifice either opens and allows it to pass, or by a convulsive effort the muscles of the stomach contract upon it, ejecting it through the meat-pipe and mouth.HBH 165.2

346. What change is effected upon the food in the stomach, and how?HBH 166.1

The nutritious portion of the food, or that which can be assimilated and elaborated for the building-up processes of the system, is converted into a substance called chyme. This substance differs from anything in the food when it is received into the stomach. It is identical in character, whatever may be the food from which it is formed; but it differs in quality with the quality of the food eaten. This change in the food in the stomach is principally effected by the vital action of the gastric juice. The chemical and physiological character of the gastric juice is very considerably affected by the dietetic habits, general state of the health, the affections of the mind, and the condition of the stomach. After the food is received into the stomach, and the process of gastric digestion is to be commenced, the temperature of the stomach is raised to about 100 or 104 degrees Fahrenheit, and this gastric juice, when the stomach is heated, is of a solvent nature, having power to chymify the food.HBH 166.2

347. Is all the food in the stomach chymified at once?HBH 166.3

No; that portion of the food which comes in contact with the mucous membrane is converted into chyme and by the muscular action is forced through the pylorus. Then another portion of the food comes in contact with it, and so on until all that can be is chymified. The innutritious portion is separated from the nutritious, and reduced to such a condition as to fit it to pass along the alimentary tube as excrementitious matter. As soon as the food is chymified and passes from the stomach, that organ is left entirely empty and clean, and contracts upon itself, and remains in this state till some alimentary or other substance is introduced into it. When the stomach is in a healthy condition, after it has had a suitable amount of rest, and just when nature wants it, it causes the manifestation of feeling called hunger. Some mistake a tired feeling in the stomach for hunger. It is folly to talk of real hunger in less than six hours from the time we have taken a full meal.HBH 166.4

348. What time is requisite for the stomach to digest a meal?HBH 167.1

This varies with the quality of the food, the condition of the stomach, and the varying circumstances and condition of the individual; but as a general rule, the food received at an ordinary meal undergoes the process of gastric digestion, and passes from the stomach into the duodenum, in from two to five hours. When water, or milk, or liquid food holding in solution particles of aliment, such as soups, etc., are taken into the stomach, the water is all taken up by the radicles of the veins, and carried unchanged into the circulation, before the process of digestion is commenced. If the stomach is in a healthy condition, the water is all removed by absorption in a very few minutes. In some cases of chronic disease, as dyspepsia, the water remains in the stomach, causing flatulence and acidity, and retarding digestion for hours, until large portions of it are thrown up with portions of undigested food.HBH 167.2

349. Why is it essential to keep the stomach in a healthy condition?HBH 168.1

Because the alimentary cavity is the principal avenue through which the causes of disease commit their depredations on the vital domain. The stomach is peculiarly a center of irritation, and a starting-point of disease to the whole body. Whatever is unfriendly to the vital interests, that impairs the nervous power, or muscular contractility, or in any way disturbs the functions of the stomach, more or less impairs the quality of the chyme elaborated from the food, and this directly leads to a deterioration of all the fluids and solids of the body. Let it also be borne in mind that the heart, lungs, liver, and all other organs of the body, directly sympathize with all irritations and disease of the stomach?HBH 168.2

350. How must the stomach act to be kept constantly in a healthy condition?HBH 168.3

All its mucous surface needs to be in a condition to be brought in contact with the alimentary substance placed in it; but this cannot be the case when it is seared over with pepper, spices, and other condiments. Articles of an injurious character, and causing feelings of repugnance in the stomach when first placed in it, irritate it, and destroy its organic sensibility in a great measure, or at least to that extent that substances of the most deleterious character may be thrown into the gastric cavity, working out the destruction of our lives, and we not be conscious of it. The appetite, and even the stomach, may be so depraved that they will receive these life-destroying substances with great satisfaction, and the person using them declare that they are not injurious, because they sit well upon their stomachs; when the facts are, that the stomach has lost the power to discriminate between good and evil, and to give the proper alarm when the vital interests are in jeopardy.HBH 168.4

351. What is connected with the pyloric orifice of the stomach?HBH 169.1

The alimentary tube or small intestine, which is six or eight times the length of the body, and is nicely folded so as to be brought into a small compass. A portion of this is seen at f, f, k, Fig. XVI. It is about twenty-five feet in length, and is divided into three parts, called by physiologists the duodenum, the jejunum, and the ileum. This tube at its lower portion suddenly expands into what is called the colon, which is more capacious than the small intestine. The colon ascends to the stomach on the right side, arches over the whole volume of the small intestine, and descends on the left side, forming, in its lowest part, what is called the sigmoid flexure, which is in the shape of a letter S. This enters into the formation of a smaller tube called the rectum, at the lower end of which the mucous membrane again blends with the outer skin of the body.HBH 169.2

352. How is the intestinal tube lubricated so as to preserve it from the injurious action of substances introduced into it?HBH 169.3

Throughout its whole extent it is furnished with glandular follicles, which copiously secrete, and pour upon its surface, a lubricating and sheathing mucous. By this mucous the whole extent of the tube is preserved from injury.HBH 169.4

353. What is the second stomach?HBH 170.1

It is the first portion of the alimentary tube below the stomach, called the duodenum; which, as its name signifies, is about twelve finger-breadths long. From the pyloric orifice of the stomach it extends upward and backward toward the liver, turns down, and then, deeply situated, (see f, Fig. XVI,) crosses to the left side and comes forward again.HBH 170.2

354. What are the appendages of the duodenum?HBH 170.3

Its glands, called Bruner’s, Lieberkuhn’s, and Peyer’s, and the pancreas, the liver, and the gall bladder.HBH 170.4

355. What is the pancreas?HBH 170.5

The pancreas is a long, flat gland, six inches long, one inch thick, and weighs from four to six ounces: situated across the abdomen, behind the stomach, opposite the first and second lumbar vertebrae. Its greater end or head is toward the right, surrounded by the curve of the duodenum; the lesser end extends to the left as far as the spleen. The duct through which the pancreas pours its juice into the duodenum, enters the duodenum about four inches below the pyloric orifice of the stomach. The pancreas, in structure and in the character of its secretion, very closely resembles the salivary glands.HBH 170.6

356. What is the office of the pancreas?HBH 170.7

To secrete and pour into the second stomach the pancreatic fluid, which is employed in perfecting the process of chymification in the small intestine.HBH 170.8

357. What other appendage to the duodenum has its duct, entering at the same point with the pancreatic duct?HBH 170.9

The largest gland in the body, called the liver. It is situated at the top of the abdominal cavity, and lies immediately under the diaphragm, and mostly on the right side. It measures about twelve inches through its longest diameter, and weighs about four pounds. It is divided into a large lobe and two small ones. On the lower surface of the large lobe, which lies on the right side, is formed a membranous reservoir, called the gall-bladder, which is also lined by the mucous membrane. The common biliary duct, after proceeding a short distance from the small intestine, gives off a tube called the cystic duct, which goes to the gall-bladder. The capacity of the gall-bladder is from one to three ounces. The remaining portion of the tube is called the hepatic duct, which soon divides, forming two tubes, one of which goes to the right and the other to the left lobe of the liver. The liver is held in its place, and attached to the diaphragm, by five ligaments. The nerves of the liver are very numerous, and by them it is brought into powerful sympathetic relations with the stomach. The gall-bladder serves simply as a reservoir for the bile.HBH 170.10

358. What is the structure of the liver?HBH 171.1

It is merely a collection of parts similar to each other, called lobules; these are bound together by a small number of sinewy fibers.HBH 171.2

359. What is the office of the liver?HBH 171.3

To secrete the bile of the venous blood from the capillaries which penetrate every part of the liver, and pour it into the bile ducts. The grand function of the liver is that of a cleansing organ, and is evidently designed to act the part of a filter, in separating impurities from the venous blood of the portal system, coming from the tissues of the alimentary canal. If the liver does not duly eliminate the bile, the blood will become thick, the skin dingy, the head oppressed, the mind confused, the nerves weak and irritable, and the eyes yellowish.HBH 171.4

360. What purpose does the bile serve in the vital economy?HBH 172.1

Although the bile is an excrementitious substance, yet at times it serves an important purpose in the vital economy. If there is too much acid in our food, it is sometimes neutralized by the action of the bile upon it, the bile being of an alkaline character. Oily substances which have passed into the duodenum, are acted upon by the alkali of the bile, converting them into a saponaceous substance, which is immediately acted upon by the pancreatic juice, and other chymifying agents, and with difficulty converted into chyme. When there is a considerable amount of fatty matter connected with our food, it cannot be so far chymified in the stomach as to pass with safety into the duodenum. The stomach becomes irritated with its unmanageable contents, and through the organic nerves a sympathy is created in the biliary apparatus, which pours its bile freely into the duodenum, and, instead of the bile taking its usual descending course, it is carried up and admitted through the pyloric orifice to convert the oil and fat into a saponaceous substance, that they can be acted upon by the juices of the stomach. This necessary introduction of bile into the stomach is contrary to the perfect functional integrity of that organ, and it seems to me that all will say, it is better to let these oily foods alone, than to have a chandler’s shop in the stomach.HBH 172.2

361. What purpose is served by Bruner’s, Lieberkuhn’s, and Peyer’s glands?HBH 172.3

They secrete from the blood, and pour into the duodenum, different kinds of juices, which serve their purpose in the chymifying process. It is supposed that the intestinal juice from Lieberkuhn’s glands turns the starch of the food into sugar.HBH 173.1

362. What is the office of the duodenum?HBH 173.2

To further the chymifying process commenced in the stomach, and prepare the nutritive portions of food to pass into the lacteals of the intestinal tube as chyle.HBH 173.3

363. How is the action of the duodenum accomplished?HBH 173.4

As the chyme passes from the gastric cavity into the duodenum, it is instantly perceived by the nerves of organic sensibility, and through them the muscles of the part are excited to action, causing a worm-like motion, by the contraction of the muscles from above downward. By this motion the chyme is slowly carried along the intestinal tube, its course being considerably retarded by the folds of the mucous membrane. While the chyme is passing along the tube, a solvent fluid, nearly resembling the gastric juice, exudes from the vessels of the membrane. As soon as the chyme enters the small intestine, the pancreatic, hepatic, and intestinal juices are poured upon it, and such changes are wrought in it, as gradually adapt all the usable parts to pass into the circulation. At the very entrance of the small intestine, the lacteals, which very numerously abound in this section of the alimentary canal, begin to act on the most perfectly assimilated portions of it, and to elaborate from it their peculiar fluid, called the chyle. As the chyme moves slowly along the living tube, the lacteals in that part of the intestine are acting on the most perfectly assimilated portion of the chyme, and at the same time the less perfectly assimilated portions are preparing for the lacteals of the succeeding part.HBH 173.5

364. What are the jejunum and ileum?HBH 174.1

They are that portion of the small intestine usually called the mesenteric portion. They are merely extensions of the duodenum, with slight modifications. The jejunum is the upper two-fifths below the duodenum. The ileum is the lower three-fifths. It opens into the large intestine at an obtuse angle.HBH 174.2

365. What function is accomplished in the jejunum and ileum?HBH 174.3

It is supposed that the completion of the work of chylification, and the preparation of excrementitious matter for its passage from the system, is mainly accomplished in these parts.HBH 174.4

366. What is essential to the perfect performance of the work of the small intestine, including both chymification and chylification?HBH 174.5

In order that this work may be performed with integrity, the stomach should not be employed at the same time. For this reason food should not be eaten between meals, and our meals should be at least six hours apart, and be eaten with regularity. See the chapter on diet.HBH 174.6

367. What is the mesentery, and what is its use?HBH 174.7

It is the portion of the serous membrane which secures the small intestine. It forms a gathered or folded curtain, which extends from the back-bone to the convolutions and arches of the canal. While it holds every part in its relative position, it admits of a full floating motion of the whole.HBH 174.8

The mesentery abounds with lymphatic vessels and glands. In these glands the chyle which as been elaborated from the small intestine, passes, and by their action is more and more assimilated to the blood. It is supposed that the chyle, in passing through these glands, has separated from it a portion of the crude substances that may be connected with it. As a large number, if not all, of these lacteals traverse a portion of the liver before pouring their contents into the thoracic duct, it is probable that they there communicate to the venous capillaries the remaining crudities and unassimilated substances contained in the chyle. The thoracic duct, as we noticed in the chapter on the lymphatics, pours its contents into the venous blood just before it enters the right auricle of the heart; from this it passes to the right ventricle, is forced into the lungs, and on returning to the left auricle of the heart, is fitted to enter the general circulation.HBH 175.1

368. What is the large intestine?HBH 175.2

It is the last portion of the alimentary tube. It is about five feet in length, and is divided into the caecum, colon, and rectum. The caecum is the most dilated portion of the intestinal tube. The colon is divided into transverse, ascending, and descending. It makes a remarkable curve upon itself, called the sigmoid flexure. The large intestine commences within the right hip; it then ascends to the liver, turns across the abdomen to the left side, down which it follows, curving over the inner surface of the hip, and then becomes straight. The rectum is the termination of the large intestine.HBH 175.3

369. What is the meso-colon?HBH 175.4

It is the membranous curtain which holds the colon in its position, similar to the mesentery.HBH 175.5

370. What is the omentum, or caul?HBH 176.1

It is the folds of the membranous curtain from the stomach, the arch of the colon, and the liver.HBH 176.2

371. What is essential to a healthy condition of the large intestine?HBH 176.3

A regular daily evacuation of the accumulations in the colon, a short time after rising in the morning. A healthy condition of the bowels demands, not only a regular discharge each day, and at a regular time of day, but that each discharge be free, easy, and copious, but not watery, and without pain, straining, or irritation. Constipated and irregular action of the bowels, give rise to most of the diseases that may be named. To purge the bowels with physic only leaves them in a worse condition than before. In case of a constipated and fevered condition of the bowels, freely use tepid injections of pure, soft water, and secure at least one good passage at the regular time in the twenty-four hours. It is best, however, to reduce the heat of the abdomen by external applications to the bowels of cool cloths-not cold, except in severe fever. When severe diarrhea occurs, mild sitz baths and cool injections may be occasionally employed to advantage.HBH 176.4

372. What habits, aside from irregularities in diet, tend to produce a diseased condition of the bowels?HBH 176.5

Tight clothing or bandages just above the hips, will tend to obstruct the passage of the contents of the colon, both from it upward into the transverse, and from it downward into the descending. By such pernicious habits the colon is constricted, faecal matter accumulates in it, and life is destroyed as the result. Thousands thus perish every year. To secure a healthy action of the alimentary tube throughout its whole extent, proper care must be had of the colon. Clothing should not be fastened upon the hips, but should hang suspended from the shoulders, and be worn loosely around the body.HBH 176.6

THE ABDOMINAL VISCERA

THE SPLEEN