The Creator, great he, out of his prudent care for man and his prudent knowledge of what is good for him, created the intestines, that is, the organs for expelling compacted excesses, numerous and having many turns and turns, so that the food descending from the stomach, as many you need to stay in these turns and turns. After all, if the intestines were created from one intestine or from short intestines, then food would quickly come out of the stomach, and a person would have to eat food every minute and continuously, and all the time defecate and get up to relieve himself. The first would occupy him and distract him from the activities necessary for existence, and the second would cause constant torment, and the person would suffer from gluttony and would resemble animals. Therefore the Creator, great he is, increased the number of intestines and the length of many of them for the sake of the first utility and multiplied the number of their turns for the sake of the second. And another usefulness of the intestines is that the vessels connecting the liver with the organs of digestion of food, with their mouths penetrating into the membranes of the stomach, or rather into the membranes of the intestines, attract only the rarefied part of the food, and from this rarefied part they attract only that which which comes into contact with them. As for that part that is hidden from them and hidden in the depths of the food substance, far from contact with the mouths of the vessels, then attracting them is either impossible or difficult. And so the creator, great he, multiplied, by his mercy, the convolutions of the intestines, so that the nutrient, which ended up in the depths of one part of the intestines, came into contact with the mouths of the vessels in another part, and another group of vessels could suck up the pure part of the food that had escaped from intestines of the first group.
The number of intestines is six. The first of these is the one called the duodenum, then comes the intestine called the jejunum, then the long winding intestine called the small or tortuous intestine, then the intestine called the cecum, then the intestine called the colon, and then the intestine called the rectum. , that is, the gut of surmise. All these intestines are connected to the spine by means of ligaments, which attach them as their position requires. The upper intestines are created thin in substance, because it is more necessary for them to digest their contents and pass the digestive power of the liver to it than is necessary for the lower intestines, and also because their contents are rarefied and the penetration and passage of it does not threaten to disrupt the integrity of the intestinal substance and scratch it . And the lower intestines, starting with the cecum, are thick, dense and lined inside with fat to resist feces, which hardens and thickens most there and is subject to rotting there when it begins to rot. There is no fat on the upper intestines, but they are created not without adhesive lubricant on the inner surface in the form of viscous mucous moisture, which replaces fat.
The duodenum connects to the fundus of the stomach and has an opening adjacent to the stomach called the pylorus. The purpose of this intestine is generally opposite to the purpose of the esophagus: just as the esophagus exists to fill the stomach from above, so this intestine exists to be pushed out of the stomach from the bottom. It is narrower than the esophagus, and there was no need to expand it as much as the esophagus was expanded, for two reasons. One of them is that the substance passing through the esophagus is tougher, harder and larger in volume, and that which passes in this intestine is softer and smaller in volume, since it was digested in the stomach and a watery liquid was mixed with it . And the second reason is that only one of the natural forces is occupied by the substance passing through the esophagus, and although the will helps it, it helps only in one respect. This force is attractive, and it is helped by opening and widening the path for the passing substance. And what passes through the first intestine is subject to the influence of two forces. One of them is the expelling force, which acts in the stomach, and the other is the attracting force, which acts in the intestines and is helped by the heaviness arising from all food; therefore, it easily rushes even along a moderately wide path. This tube differs from the esophagus in that the esophagus is, as it were, a part of the stomach, similar to it in the structure of the membranes that form it. As for the duodenal tube, it is like something extraneous, adjacent to the stomach, but differing in the substance of the membranes from the membranes of the stomach, since the stomach needs the ability to retract strongly, which the intestine does not need; Therefore, in the membranes of the duodenum, fibers running transversely predominate, and in the rectum many longitudinal fibers are visible, for it cleanses the other intestines and acts with great force and must draw in the substance located above. Longitudinal fibers help it squeeze, push out and remove feces well; if there is little feces, it does not obey squeezing, so the rectum is created wide and its cavity is large. The duodenum is created, as a precaution, with two membranes, so that the destruction and decay to which this intestine is predisposed does not spread quickly at the slightest damage to it, and also because of the difference in the actions of the two membranes. This tube is created in a straight shape and stretches down from the stomach so that the initial rush of nutrients from the stomach is carried out easily, since the passage of something heavy down an elongated vertical passage occurs more quickly than along a tortuous or horizontal one. This form of this intestine is useful in another respect, namely, that since it runs vertically, to the right and left of there remains room for other organs adjacent to the stomach on both sides, that is, for part of the liver on the left and for the spleen on the right. This intestine was called the duodenum because its length is equal to the width of the number of fingers of its owner. Its width is the width of its mouth, called
The part of the small intestine adjacent to the duodenum is called the jejunum; The convolutions, bends and turns of the intestine begin from this part and there are many ducts in it. This colon is called fasting because it is mostly empty, not filled, and the reason for this is two mutually promoting circumstances. The first is that the chyle, which is drawn into this intestine, hastens to leave it and part of it is carried away to the liver, for most of the vessels of the mesentery are connected to this intestine, since this intestine is closer than other intestines to the liver and no other intestine has so many branches mesenteric vessels, as in this one, and then in the duodenum. The jejunum narrows greatly, collapses and decreases in disease. And the other part of the chyle is washed out of it into the intestines located below, for yellow bile seeps from the gallbladder into this intestine, while still pure, not mixed with anything. Its expelling power is considerable, and it excites the expelling power of the intestines by its pungency; by washing, it helps push the food gruel to the bottom, and by stimulating the expelling force, it helps push it in both directions at the same time, that is, both to the liver and down. These circumstances lead to the fact that this part of the intestine remains empty, and therefore it is called fasting.
Adjacent to the jejunum is a part of the intestine that is long, tortuous and describes several curves one after another. We have already explained the usefulness of its many twists and turns in the previous parts of this paragraph; it consists in the fact that the nutrient is retained in this part of the intestine and, thanks to such retention, constantly, time after time, comes into contact with the mouths of the suction vessels. This intestine is the last of the intestines called the small intestines; Digestion is carried out in them to a greater extent than in the lower intestines, which are called large, for the main action of the lower intestines is to prepare feces for eruption. However, they are also not deprived of the ability to digest, just as they are not deprived of hepatic vessels, which are directed to them for absorption and attraction of chyle.
Adjacent to the lower part of the small intestines is a small intestine called the cecum. It is called so because it has only one mouth; through him she receives what comes into her from above, and through him she brings out and expels what is brought out of her; it is located slightly posteriorly and deviates to the right. This gut was created for several benefits. One of them is that there is a place for feces where it is locked, so that a person does not have to get up every minute to relieve himself, and a little feces does not end up in the lower intestines all the time; on the contrary, the cecum serves as a repository in which the feces are collected whole, and then easily ejected when the formation of feces is completed. Another usefulness is that this intestine is the first of the intestines in which the conversion of nutrients into something like feces is completed and prepared for new absorption by the vessels of the mesentery, although this absorption does not take place while the food is moving, moving and dispersing . On the contrary, it occurs only afterward, when the nutrient leaves the liver, but remains close to it, so that, due to its proximity, the action of secondary digestion after digestion in the stomach reaches it. This digestion takes place due to immobility and proximity, when the nutrient is accumulated and locked in one place, where it remains motionless and collected for a long time.
The relation of the cecum to the large intestines is the same as the relation of the stomach to the small intestines; therefore, the nutrient must be close to the liver so that the liver can carry out complete digestion and so that the remainder of the nutrient, which is not digested and not suitable for absorption by the liver, is converted into the best substance into which it can be converted. This residue did not submit to the action of the stomach and was not completely digested due to the abundance of matter, and also because the easily digestible substance is susceptible to action earlier, since it covers in the stomach the difficult to digest; now in the cecum the substance is difficult to digest in itself, and when the active force reaches it, it finds it prepared and naked of everything except the excess, which must turn into feces. A less obedient part of the nutrients exists in both cases, but in the stomach it is found together with another substance covering it, and in the cecum it alone is covering. The substance mixed with the covering substance in the stomach is rather exposed in the cecum to the action of the digestive force, especially since in the stomach it has not escaped some action and digestion, and is ready to receive the full action and digestion, having been exposed to the influence of the acting force.
Thus, the cecum is the intestine in which the digestion of that which is not subject to the stomach and turns out to be the waste of digested food submissive to the stomach is completed. The amount of substance which covers these wastes in the Caecum and separates them from the easily absorbed moist chyle is small, and they have become so digestible that even a small acting force corrects them, if they find a place for themselves and remain there until digestion is completed. Then they leave it and move into the large intestines, from where they are absorbed by the vessels of the anus. Some people say that this intestine was created blind so that chyle could reside in it and so that the liver could completely cleanse it of the nutrient remaining in it, and they believe that the vessels of the mesentery reach only to the cecum. But the one who conveys this is mistaken, and the usefulness of the cecum is as we have explained.
This intestine has only one mouth, since it does not lie along the body, as the stomach does. The usefulness of its blindness also lies in the fact that it collects excess in itself, and if all these excesses passed into other intestines, one could be afraid of the occurrence of kulanj. Accumulating in the cecum, they deviate from the passages and can, since they are collected in one place, rush out of nature at once, for what is collected is ejected more easily than what is scattered. Another usefulness of the cecum is that it serves as a shelter for the creatures that inevitably arise in the intestines, that is, for worms and snakes: the human body rarely remains free of them. The birth of worms also has its benefits, if their number is small and their size is small. This intestine most likely descends into the groin gap, since it is free, not attached to anything and not attached by the mesenteric vessels going to it; some even say that no mesenteric vessels pass through it.
The intestine, called the colon, is adjacent to the cecum from below: this is a thick, dense intestine. Moving away from the cecum, it deviates thoroughly to the right to approach the liver, and then goes to the left, also going down, and here it adjoins the rectum. As it passes by the spleen, it narrows, and therefore the enlargement of the spleen does not allow the winds to escape unless pressure is applied to the spleen. The usefulness of this intestine is that it collects and retains feces and gradually prepares it for expulsion, completely sucking out the remaining nutrients, if any, from it. Kulanj most often occurs in this intestine, and the name of this disease is derived from it.
The rectum, and this is the last of the intestines, adjoins the lower part of the colon colon, then descends from it in a straight direction and reaches the anus, resting on the lumbar vertebrae; at the same time, it expands so much that it almost resembles a stomach, especially in its lower part. The usefulness of this intestine is the ejection of feces outward. The Creator, great he is, created four muscles in this intestine, as you already know. This intestine was created straight so that feces could be expelled from it more easily. The muscles that promote the expulsion of feces are not in the rectum, but in the walls of the abdomen, and there are eight of these muscles.
Let this be sufficient in regard to the anatomy of the intestines and the mention of their usefulness. None of the organs which are passages for food are moved by muscles, except at both ends of the passage—I mean the apex, that is, the esophagus and throat, and the lower end, that is, the anus. Veins, arteries and nerves go to all the intestines, and there are more nerves in them than nerves in the liver, because the intestines need greater sensitivity.