Anatomy of the esophagus and stomach

As for the esophagus, it consists of meat and membranous membranes with longitudinal fibers lining it from the inside. This structure makes it easier to attract the bolus when swallowing; as you already know, attraction occurs precisely as a result of the contraction of longitudinal fibers. The top of the esophagus is covered with a membrane with transverse fibers that facilitate pushing the bolus of food down; you already know that pushing is carried out precisely by transverse fibers. The esophagus is characterized by obvious fleshiness. Thanks to the combined action of both membranes, swallowing occurs, that is, due to the fact that some fibers retract and other fibers push. Sometimes a person whose esophagus has been cut lengthwise may have difficulty swallowing because there are no fibers to help food move down. And vomiting is carried out using only the outer membrane, so it is accomplished with great difficulty.

The esophagus is located on top of a vertebra located in the neck; it lies upright and is well and securely protected. A pair of nerves coming from the brain descend along with it. Having passed parallel to the fourth vertebra of the spinal vertebrae related to the chest, and having passed this vertebra, the esophagus bends slightly to the right to make room for the vessel coming from the heart. Then it descends along the remaining eight vertebrae and, having reached the septum, is attached to it with the help of a ligament, which slightly raises it so that it does not put pressure on the part of the large vessel passing through the barrier, and so that the accompanying nerves descend obliquely; this protects them from the danger of vertical tension when the stomach is burdened. Passing near the thoraco-abdominal obstruction, the esophagus deviates to the left, just as it previously deviated to the right; The esophagus makes this reverse turn to the left, passing the tenth vertebra and heading towards the eleventh and twelfth vertebrae. After penetration into the thoraco-abdominal barrier, the esophagus expands and expands in breadth, forming the mouth of the stomach; Below the esophagus lies the voluminous body of the stomach.

The inside of the esophagus is created wider and denser than the first intestine, because the esophagus serves as a passage for more solid food. The inner lining of the stomach is average in hardness and is softest at the mouth of the stomach; the intestinal lining is even softer. The inside of the esophagus is lined with a membrane that extends to the end of the stomach and starts from the membrane of the mouth, so that the retraction of food is continuous and so that the tension of the esophagus downwards during swallowing helps to raise the larynx upward. If you check properly, you will be convinced that the esophagus is part of the stomach and gradually expands towards it and that both of its membranes are similar to the membranes of the stomach. The inner shell is more like a membrane and stretches lengthwise, and the outer shell is fleshy, wide, thick and has cross-fibers. It is more fleshy than the stomach, but forms a part of the stomach, similar in structure to it and connected with it. As for the first intestine, it is not part of the stomach, but something closely related to it; therefore, it does not narrow towards the stomach, and its membranes are not similar to the membranes of the stomach. The substance of the esophagus is more like muscles, and the substance of the stomach is more like nerves. The part of the stomach adjacent to the esophagus and adjacent to the sacral obstruction narrows in the form of a cone, and at the bottom it expands, since the place where the food resides is located at the bottom and it should be wider. The stomach is created round for the sake of the usefulness that you know, and at the back it is flattened so that its contact with the spinal ridge is greatest.

The stomach consists of two membranes. The fibers of the inner membrane are longitudinal for the sake of the well-known need to draw in food, so when swallowing the stomach contracts and the larynx rises upward. And the outer shell has transverse fibers for the sake of the need to push, known to you. The pushing fibers are located outside because retraction is the first and immediate action of the stomach, and pushing occurs after this and ends with the successive compression of the entire food container in order to expel its contents. Oblique fibers are mixed into the fibers of the inner shell to help retain food. They are in a retractive, not a push-through, sheath and are not mixed with the fibers of the outer sheath. The esophagus also does not need them, because it does not serve to retain food. The entire inner membrane is rich in nerves, since it is in contact with dense substances; As for the outer shell, it is more fleshy at the bottom so that it is hotter and digests better.

There are more nerves at the mouth of the stomach to make it more sensitive. A branch of nerves from the brain goes to it, giving it sensitivity so that it feels hunger and responds to lack of food; all other parts of the stomach behind the mouth do not need this, for the stomach needs sensitivity only so that it is alert when the body is free from food, and if the anterior end of the stomach is sensitive and earns food for itself and for other parts, then the parts located behind him, do not need sensitivity, since he takes care of others. This nerve comes down from above, winding around the esophagus. It forms one turn around it near the stomach and then adjoins the stomach. At the most convex place of the stomach lies a large vein, which runs along the stomach and sends to it many branches connected to it by thin branches that merge into one row. This vein is also accompanied by an artery, from which similar branches also emerge. Both vessels rest on a fold of the peritoneum; an omentum is woven from their branches, as we will describe below. The stomach digests thanks to the innate warmth of its meat and other warmth that it receives from neighboring organs.

The liver lies to the right of the stomach and on top, for in this place the liver has a narrowing, and it stretches out comfortably on the stomach. And the spleen spreads under the stomach on the left; it is a little removed from the barrier because of its impurity, and also because if the spleen and liver were to lie together on the stomach, it would undoubtedly burden the stomach. And it was considered best for the liver to lie on the stomach, covering the entire stomach with appendages stretching out like fingers, and the spleen would spread below. In addition, the liver is very large in comparison with the spleen, for it must be large, and how could it be otherwise, since the spleen accommodates only part of the excess coming from the liver? It was therefore necessary to deflect the apex of the stomach to the left to give room to the liver, to narrow it on the left side, to deflect its lower part to the left into the space not occupied by the liver below, and also to give ample space to the spleen on the left and below. And the most honorable side, that is, the upper and right, was assigned to the liver, and the worst, opposite to the spleen. In front, the stomach is warmed by the omentum, which stretches along the stomach and throughout all the intestines, especially in humans, for humans need the help of heat more during digestion, since their digestive powers are weaker than those of other animals. The omentum is made dense to retain heat, thin to be light, and fat to retain heat in the front part of the stomach, for the fatty substance absorbs heat very well and retains it due to its oily viscosity. Above the membranous omentum you will find a membrane called barituna, even above the abdominal wall and abdominal muscles, completely covered with fat. These two shells converge at the top, at the chest barrier, and diverge at the bottom; behind them is the spinal column, along which stretches a large hot beating vessel; it is hot due to the great warmth of its pneuma and blood; This vessel is accompanied by a very large vein.

The peritoneum is one of these membranes. This is the first membrane that covers all the insides that serve for nutrition; it covers these insides, goes inward and closes at the spine on both sides; its upper end adjoins the thoraco-abdominal barrier, and its lower end adjoins the lower part of the bladder and the groins. Here in the peritoneum there are two openings near the ilium; these are passages into which vessels and suspensory organs are passed; when these openings expand, the intestines descend into them. The usefulness of the peritoneum is that it protects the insides and separates the intestines from the muscles of the abdominal walls, so that the intestines do not get between the muscles and interfere with their actions. The known membranes located in the abdominal cavity also participate in this with the peritoneum. The outer shell, that is, the walls of the abdomen, also has some benefits: it compresses the stomach with the movements of its muscles and sets it in motion. All these muscles stretch on receptacles containing ejected substances and must push them out through some compression that promotes excretion; these muscles also compress the bladder, promoting the ejection of urine, and squeeze out some of the distending winds that need to be expelled so that they do not weaken the bowels, and also help in delivery.

The peritoneum connects all the insides with each other and connects them to the spine; their connection turns out to be reliable, and the peritoneum forms something unified with the spine. When the peritoneum reaches the thoraco-abdominal barrier and its edges converge at the spine, it attaches to it in this place and its origin comes from there. Its beginning is the part that descends from the obstruction to the mouth of the stomach; there it is met by a part that rises from the mouth of the stomach to the spinal column, and the two parts are connected. Starting from here, the peritoneum is a membranous body that is not divided into visible fibers; on the contrary, it is a body that is smooth in appearance. It covers the stomach over the two membranes present in the substance of the stomach and serves as protection for the fleshy membrane of the stomach. The peritoneum connects with the stomach and connects it with the organs lying near the spine; it forms a fold, an ascending part and a descending part. The peritoneum is thickest at the bottom and on the left: it is covered with an enveloping layer of thinning abdominal muscles, under which there is a thin part, which is the true peritoneum; it is very thin, and from it grows a membrane that lines the inside of the chest cavity.

Where the peritoneum begins, there is an excess piece of membrane on both sides. From this piece and from the branches of two vessels, the substance of the omentum. It consists, depending on the location, of two or more fatty membranes: which lie one above the other. The omentum covers the stomach, intestines, spleen, and mesentery, folding toward the flat side of the stomach. This omentum, although it lies separately, is connected with the other viscera by means of cords coming from the stomach, from the concave part of the spleen and the places where its arteries pass, from the glands located between the suction vessels, which are called masarika, and from the duodenum. However, these cords are small and weak, so that the omentum sometimes connects with the liver and false ribs almost imperceptibly. The cords are the place from which the omentum grows: the first of them is the cord coming from the stomach. The oil seal is like a bag; If you pour something liquid into it, it will retain the liquid. If you examine this matter carefully, you will be convinced that the skin and the fleshy membrane lying under it, as well as the muscles located in the upper layer of the known muscles of the stomach, are considered to be part of the duckling of the abdomen, and the lower layer of the abdominal muscles and the thin membrane, which is the true peritoneum, are included in the membranes of the abdominal cavity. The omentum is like the lining of the peritoneum and the outer clothing of the stomach. All these bodies mutually contribute to the warming of the stomach, just as they contribute to its protection.

In the lower part of the stomach there is an opening to which the duodenum adjoins; this opening is called the pylorus. It is narrower than the upper opening, since digested and softened food passes through it, and the upper one serves as a passage for substances opposite to it. The lower opening remains compressed until food digestion is completed; then it opens and remains open until the eruption from the stomach ends. Know that the stomach is nourished in three ways: firstly, by what it digests while the food is still in it, secondly, by nutrients entering it from the vessels mentioned in the anatomy of blood vessels, and thirdly, red pure blood, which pours into him from the liver during severe hunger and nourishes him. Know that the ancients, when they said “the mouth of the stomach,” sometimes meant the entrance to the stomach, that is, a narrow place in the part of the stomach that has not yet expanded, located behind the esophagus, and sometimes the upper part of the entrance, which is the common boundary between the esophagus and the stomach. Some people call this place fuad and qalb, while others use the expression “mouth of the stomach” in conversation, meaning the heart. This is due to the commonality of names or the inability to distinguish, and this is how very ancient doctors expressed it. As for Hippocrates, he often says: “heart,” but, judging by his interpretation, he means the mouth of the stomach.