The liver is the organ that completes the formation of blood, although the vessels of the mesentery convert chyle into blood to some extent, since they have the ability inherent in the liver. Blood is actually a nutrient that has been turned into something similar to liver, which is red meat, like blood, but congealed blood. The liver is devoid of nerve threads. Vessels are scattered in it, which represent the roots of what grows from it, dividing like fibers, as you already learned from the paragraph on the anatomy of resting vessels. The liver absorbs chyle from the stomach and intestines through branches of the portal vein, called mesenteric vessels and coming from its concave part. She boils the chyle there, turning it into blood, and sends it into the body through a hollow vessel growing from its bulge; it directs the watery part of the chyle to the kidneys through its convexity, and directs the bile foam into the gallbladder through the concave part, over the “gate”; It directs the black gall sediment to the spleen also through the concave part. The part of the liver adjacent to the stomach is concave so that it is well located on the convexity of the stomach, and the part adjacent to the abdominal obstruction is convex so that the freedom of movement of the obstruction is not constrained; on the contrary, the liver touches it almost like a point and adjoins it near a large vessel growing from it, connecting with it very firmly; This part of the liver is also convex so that the ribs curving above it cover it well.
The liver is enveloped in a sheath rich in nerves, arising from a small nerve that approaches it to give it some sensitivity, as we said in the part about the lungs - this sensitivity is most obvious on the concave side - and to connect it with other viscera. There is also a small beating vessel that goes to the liver, which divides in it; it transfers the pneuma to the liver and retains its innate warmth, balancing it with its beating. This vessel is directed precisely to the concave part of the liver because its convexity is enveloped by pneum due to the movements of the abdominal barrier. The liver does not create a large space for blood; there are only the dividing branches of the vessels, so that they all retain the chyle and so that the individual parts of the chyle are more fully and quickly exposed to the action of the liver. The vessels adjacent to the liver have a thinner membrane, so that they more quickly convey the action of the fleshy substance of the liver to the chyle. The membrane surrounding the liver connects it with the membrane enveloping the intestines and stomach, which we have already discussed, and also connects it with the thoraco-abdominal barrier through a large strong ligament; it connects the liver with the posterior ribs by other ligaments, thin and small.
The liver connects the heart to the vessel that connects them, which you already know about; it rises from the heart to the liver or rises from the liver to the heart, depending on which of these two views one adheres to. The connection of this vessel with the liver is strengthened by a hard, dense membrane passing from above the liver; the thinner side of this membrane is that adjacent to the inner side of the liver, for this is better and safer, since it touches the delicate organs. The human liver is larger than the liver of any animal close to it in size and size; they say that the more an animal eats and the weaker its heart, the larger the size of its liver. The liver connects a nerve to the stomach, which, however, is thin; therefore, the liver and stomach are involved in the disease only in very dangerous cases of tumors in the liver. First of all, two vessels grow from the liver. One of them comes out of the concave side and its greatest utility is to attract nutrients to the liver; it is called a "gate". The other comes out of the convex side; its usefulness lies in the delivery of nutrients from the liver to the organs, and it is called "hollow"; we have already outlined the anatomy of both these vessels in Book One. The liver has appendages with which it surrounds and firmly holds the stomach, just as fingers surround a grasped object. The largest of these appendages is the one that is especially distinguished by the name “appendage”; the gallbladder lies on it, and it is extended downward. The total number of appendages in the liver is four or five.
Know that the body of the liver is not in all people pressed against the back ribs and rests firmly on them, although in many this is the case. The degree of complicity in diseases depends on this, I mean the complicity of the liver with the posterior ribs and the thoraco-abdominal barrier. The fleshy substance of the liver is devoid of sensitivity, but the part of it adjacent to the membrane feels something, for it has acquired a slight sensitivity from parts of the membrane rich in nerves. Therefore, the mentioned complicity and the judgment about its degree vary from person to person. You already know that the origin of blood occurs in the liver; it separates yellow bile, black bile and the watery part of the blood. Sometimes both actions are disrupted, sometimes the generation of blood is disrupted and the separation of bile is not disrupted; if separation is disrupted, then the generation of good blood is also disrupted. Sometimes a disturbance in the separation occurs not from a cause dependent on the liver, but from a cause connected with the organs that extract from it what is separated. All four natural forces are at work in the liver, but the greatest digestive force is found in its fleshy substance, and most of the other forces are concentrated in the fibers. It is quite possible that all these forces are present in the vessels of the mesentery, although one of the later doctors objects to the ancients and says: “He who ascribes to the mesentery an attracting and retaining force is mistaken. The mesentery is only a path for what is attracted, and it cannot be allowed that she herself had the ability to attract.” In defense of this, he gives arguments similar to the weak arguments that he puts forward in all other questions, and says: “If the mesentery had an attractive power, then it would undoubtedly have a digestive power, but how can it have digestive power, if the nutrient is not retained in it so far as to be subject to any action. He goes on to say: “If the mesentery had an attractive power, and the liver too, then the substance of these organs would undoubtedly be the same due to the homogeneity of the forces.” However, this feeble-reasoning man does not know that if the attracting force is in the passage through which the attraction takes place, this is more conducive to it; in the same way, if the expelling force is present in the passage through which the substance is expelled, as, for example, in the intestines, this too promotes its action. He forgets that the attracting force is in the esophagus, although the esophagus is a passage, and does not know that there is no great harm if in any of the passages there is an attracting force and there is no digestive force, which should be taken into account, since strength is needed here not for digestion, but for attracting food. He also forgot that the chyle undergoes some transformation in the mesentery, and to deny that the reason for this is the presence in the mesentery of a digestive force, and that there is also a retaining force in it, which retains somewhat, although not for long. He also forgot that fibers intended for certain actions are of various kinds, and considered it impossible that some digestion should take place in the organs where food passes quickly. However, this is by no means impossible, and ancient doctors said that even in the mouth itself some digestion takes place. They also do not deny that the jejunum has the inherent ability to expel and digest, and it is an organ that is quickly released from its contents. This doctor forgot that it is quite acceptable for organs to differ in their substance, but participate in attracting something, although what is attracted follows a single path to all organs, and he forgot that attraction is most powerfully carried out by the liver with the help of the fibers of its vessels, which in substance they are similar to the mesentery and are not very far from it in this regard. How many mistakes has this man made in his
As for what Galen says, he means the initial, strong attraction, at which any significant movement begins; its purpose is to ward off the error of the physician, who limits himself to treating the mesentery, neglecting the liver. Proof of this are the words of Galen: “Whoever, in this disease, treats the mesentery and neglects the treatment of the liver, is like a person who would apply a medicinal bandage to a leg weakened due to damage to the brain located in the back, and would neglect to treat the source and root, that is, the spinal cord." These are the words of Galen; they are connected with the previous statement, for, as you know, the leg is not devoid of natural forces and the force of movement and feeling, the source of which is in the spinal cord. The difference between the natural strength of the leg and the strength of the spinal cord is only that the sensory and driving force is primary for one of these organs, and secondary for the other.
The situation is the same with the mesentery: it, too, is not without power, although its source is the liver. And how could it be otherwise, if the mesentery is a kind of instrument, that is, a set of natural instruments with the help of which the liver attracts substances from afar, and not through local movement, like muscles. The mesentery, in most cases, is not without a force, which spreads through it and meets the substance affected, as iron experiences the influence of a magnet and attracts other iron; it is also attracted by the air located between the iron and the magnet, as most researchers think.