Oesophagus

“ The œsophagus is a slightly flexuous canal, inclining to the left in the neck, to the right in the upper part of the thorax; it commences at the termination of the pharynx, which is a musculo-membranous sac, about four inches in length, and communicating with the cavity of the nose and mouth; the œsophagus then passes behind the arch of the aorta to the œsophagal opening in the diaphragm, where it enters the abdomen, and terminates into the stomach.
The stomach in man is an oblong, membranous bag, placed obliquely across the abdomen and just below the diaphragm ”

“ General dilatation, though sometimes congenital, is, as mentioned under Etiology, more frequently the mechanical result of distension of the oesophagus by food or drink prevented from ready entrance into the stomach by a constriction at the cardiac orifice. This form of dilatation is sometimes discovered as a post-mortem curiosity. The muscles have usually undergone great hypertrophy, and the mucous membrane some thickening and congestion, with erosions and sometimes ulcerations, indicative of chronic oesophagitis. In some instances all the coats of the oesophagus have undergone hypertrophy. ”

“ In the oesophagus the downward movement varies with the nature of the food swallowed. If it be fluid it reaches the lower end of the oesophagus in about three seconds and lies at the lower end of the gullet for two or three seconds before entering the stomach. When the consistency is firmer the progress downwards is much slower. Either by the force exerted by the wave of contraction passing down the gullet or by some inhibition of the sphincter, the cardiac orifice opens and permits the food to enter the stomach. ”

“ The cross section of the stomach is somewhat larger than that of the oesophagus, but it differs from the more anterior region mainly in the character of its walls. These are much thicker than in the oesophagus; in the mesoblast which 18 forms the greater part of their thickness, muscle fibers are beginning to differentiate. The epithelial layer also is thicker than in the oesophagus; it consists of tall columnar cells that, at places, are thrown into small folds, figure 7I. These folds, even under the low magnification used, are more evident than is shown in the present figure. ”

“ The detention of food above the stricture usually dilates the oesophagus, producing hypertrophy of the mucous membrane and submucous connective tissue, followed in its turn by fatty degeneration. Atrophy of the oesophagus may ensue below the stricture if at all tight, and the mucous membrane becomes thrown into longitudinal folds. ”

“ The action of the abdominal muscles then connects itself with that of the stomach; the viscera are propelled upwards and backwards, by the contraction of the large muscles of the abdomen; the diaphragm ascends towards the chest; if it descended, in contracting, the œsophagus that passes between its two crura would be compressed, and the expulsion of food through the cardia could not be effected. It is also observed, that during expiration only, any thing can pass from the stomach into the œsophagus." Again, on respiration, page 147—"In every effort of expiration, as coughing and vomiting," &c. ”

“ Circumscribed oesophagitis is usually indicated by odynphagia at a certain point of the tube after completing the act of deglutition. The location of the inflammation can sometimes be determined by auscultation of the descent of the alimentary bolus or of a swallow of water (Hamburger) , which may yield evidence to the ear of arrest or impediment to its passage. Auscultation of the oesophagus, however, is less useful in acute oesophagitis than in stenosis, stricture, and mechanical obstruction. ”

“ The oesophagus expands into a curious gizzard, which is armed internally with large horny processes, some broad and thick, others spinous, fitted to act as crushing instruments. From this we pass to a stomach and a coil of intestine embedded in the lobes of a voluminous liver; a caecum of large size is given off near the commencement of the intestine. The liver opens by two ducts into the digestive tract. ”

“ The mouth and pharynx can be studied to better advantage later with the dissection of portions of the vascular system.
The oesophagus can be seen above the liver, by pressing that organ aside, as a somewhat constricted tube entering the anterior end of the abdominal cavity. It immediately joins the stomach, which is more or less expanded according to the amount of food contained in it. ”

“ Heister gives a minute description of it, and very gravely enters on the mode and manner of using it: the patient is to drink a draught of warm water, or spirit of wine, that the mucus and foulness of the stomach may be washed off thereby: then, the brush being moistened in some convenient liquor, is to be introduced into the œsophagus, and slowly protruded into the stomach, by twisting round its wire handle. When arrived in the stomach, it is to be drawn up and down, and through the œsophagus, like the sucker in a syringe, till it be at last wholly extracted. ”

“ Traction diverticula of the oesophagus not uncommonly occur as sequels to suppurative inflammation of cervical lymphatic glands. More frequently dilatation of a section is met with, due as a rule to the presence of a stricture. The stomach often diverges from the normal in size, shape and position. Normally capable in the adult of containing from fifty to sixty ounces, either by reason of organic disease, or as the result of functional disturbance, its capacity may vary enormously. ”

“ Now cut oesophagus just in front of stomach, and cut the rectum, cut through the mesentery supporting the intestine, and remove and unravel alimentary canal; cut open, wash out, and examine caecum and stomach. Bleeding to a considerable extent is inevitable, chiefly from the portal vein. The liver had better remain if the same rabbit is to serve for the second dissection. ”

“ The œsophageal tube is of very simple anatomical construction, and performs an equally simple physiological function; nevertheless, in the ox it is liable to a large number of diseased conditions. These conditions may affect only a circumscribed area of the mucous membrane or the entire extent of the tube. Again, both the muscular and mucous tissues may be affected, as in inflammation of the œsophagus accompanied or followed by contraction, and in the formation of œsophageal abscesses and tumours; or the muscular tissue alone may be affected, as in cases of dilatation. ”

“ DIAGNOSIS.—The diagnosis of organic stricture of the oesophagus rarely presents difficulty. Dysphagia, spasm, and regurgitation are quite characteristic of stricture. When the constriction is high up, the vomiting or regurgitation of food may closely follow its deglutition; when low down, this act may be delayed ten or fifteen minutes, in some cases for hours. Alkaline reaction of the vomited matters is indicative of their having failed to reach the stomach. The presence of blood-cells, pus-cells, and cancer-cells indicates ulceration, suppuration, and malignant disease, respectively. ”

“ Œsophagotomy.—This operation is very rarely required, and has as yet been performed only for the removal of foreign bodies impacted in the œsophagus, and interfering with respiration and deglutition. To cut upon the flaccid empty œsophagus in the living body would be an extremely difficult and dangerous operation, from the manner in which it lies concealed behind the larynx, and in close contact with the great vessels. When it is distended by a foreign body, and specially if the foreign body has well-marked angles, the operation is not nearly so difficult. ”

“ Hare-lip, cleft palate, hernia and imperforate anus are physical abnormalities which are interesting to the surgeon rather than to the pathologist. The oesophagus may be the seat of a diverticulum, or blind pouch, usually situated in its lower half, which in Physical abnormalities most instances is probably partly acquired and partly congenital; a local weakness succumbing to pressure. Hypertrophy of the muscular coat of the pyloric region is an infrequent congenital gastric anomaly in infants, preventing the passage of food into the bowel, and causing death in a short time. ”

“ The pharynx communicates with the exterior through five gill slits (g.s.) , and has, of course, no glottis or other lung opening. There is a wide oesophagus passing into a U-shaped stomach (st.) , having, like the rabbit's, the spleen (sp.) on its outer curvature. There is no coiling small intestine, but the short portion, receiving the bile duct (b.d.) and duct of the pancreas (pan.) , is called the duodenum (d'dum.) . The liver has large left (L.lv.) ”

“ The œsophagus very large, like that of the serpents, gradually expanding as it descends to form the stomach, which again contracts at the commencement of the intestinal tube; the lining membrane of the œsophagus and stomach, thrown into longitudinal folds, which were continued throughout the intestines; which tube undergoes several enlargements in its course, giving it a sacculated appearance similar to the alimentary canal of the alligator; in the animal under consideration, they form several convolutions previous to their termination into the cloaca; the stomach contained an earth worm. ”

“ When the stomach is laid bare and distended above measure, fluid does not usually enter into the œsophagus, because, as we have said, the distension of the stomach is a cause which prolongs the contraction of the œsophagus. ”

“ In other cases a rough, irregular, infected foreign body may when swallowed penetrate the wall and cause inflammation, necrosis and perforation of the œsophagus.
The symptoms are always very grave, and of rapid development. They consist in local œdematous swelling, sero-sanguineous infiltration at the entrance to the chest, in the pretracheal region and along the jugular furrows.
The pneumo-gastric and inferior laryngeal nerves being compressed, dyspnœa results. If the œsophagus is perforated in the thoracic cavity septic pleurisy at once sets in. ”

“ The part in front of it, which lies dorsal to the heart, is the fore gut, while the part behind the aperture of the yolk-sac is the hind gut.
The pharynx, oesophagus, stomach and part of the duodenum are developed from the fore gut, a good deal of the colon and the rectum from the hind gut, while the mid gut is responsible for the rest. The cephalic part of the fore gut forms the pharynx (q.v.) , and about the fourth week the stomach appears as a fusiform dilatation in the straight tube. Between the two the oesophagus gradually forms as the embryo elongates. ”

“ The skull and branchial basket complete their development. At the same time the pharynx loses its connection with the rest of the alimentary canal and remains as the branchial canal. The so-called oesophagus of the adult is apparently a new formation which grows forwards and acquires a connection with the mouth. It is probable that it represents a hyperpharyngeal groove constricted off from the dorsal wall of the pharynx. ”

“ While the trachea and bronchi lie ventrad to the oesophagus, the lungs lie laterad and even dorsad to the oesophagus and cardiac end of the stomach. Caudad to the heart and in the region of the anterior appendages, aa, the oesophagus suddenly enlarges to form the stomach, i ́, which has now quite the outline of the typical human stomach. ”

“ The oesophagus begins at the upper and inner part of the mouth, which is a delicate long tube; near which there is another thick one, and made nearly like the colon, which leads to a bag, or the first stomach, which may be likened to the craw of a fowl: it is always filled with fucus mixed with sand. Sometimes this stomach is double, or at least lengthens itself considerably, and the aliment parts it, as it were, into two portions. After this craw, or stomach, we find another, which performs the same office with the gizzard of fowls. ”

“ The upper canines are developed, but are minute.
The stomach is not quite like that of Macropus, though built upon a similar plan. The blind cardiac extremity is a single, not a double cul-de-sac; in this it is like that of Petrogale. The distribution of the squamous, white, oesophageal epithelium is very much like that of Dendrolagus. In both genera the orifice of the oesophagus into the stomach is guarded by two strong longitudinal folds, which run for some distance towards the pylorus. ”

“ Fig. 10 represents the alimentary duct further magnified, from its origin to the belly. It is shewn here as separated from the animal, which is easily effected; for nature, assisted by very little art, performs the operation. The oesophagus, b c; Fig. 6 and 10, at its origin a a, is very small, but soon grows larger, as at c, and forms a kind of oblong bag, c d; the diameter of this increases till it comes to d, where it swells out as at d e f; it then grows smaller till it comes to g, when it again swells out at g k l. The part k l is the stomach. ”

“ If we examine the motions of the digestive tube when it is free of aliments, we see their difference in a manner not less striking. The œsophagus exhibits those alternate motions that we have described; a very powerful contraction of its inferior third, and then suddenly the most complete relaxation. In the stomach we see only some undulations, that go irregularly from one orifice to another. In the intestines, these motions exhibit nearly the same regularity, but the groove formed by the contraction of the annular fibres is deeper, and the undulatory motion is not so slow. ”