Portal vein

“ The junction of the main trunk of the abdominal vein with the hepatic portal vein takes place close to the liver under cover of the pancreas. A series of accessory portal veins continuous with the abdominal vein enter the ventral surface of the liver between the layers of the ventral mesogastrium. The inter-renal segment of the postcava receives the revehent renal-portal veins. The iliac vein enters the advehent renal-portal veins derived from the caudal vein. ”

“ Joining the renal portal vein is a large vein formed of two branches. The one branch arises in the abdominal wall, while the other passes along the base of the leg and joins the abdominal vein. On each side three dorso-lumbar veins join the renal portal vein. ”

“ The hepatic portal system is limited to a vein which conveys to the liver blood derived from the alimentary tract; in no mammal except in Echidna is there any representative of the anterior abdominal vein of lower vertebrates. In that animal there is such a vein, which apparently arises from a capillary network upon the bladder and passes up, supported by a membrane, along the ventral wall of the abdomen to the liver, thus emptying blood into that organ exactly as does the anterior abdominal vein of the frog. In no mammal is there any trace of a renal portal system. ”

“ After this, from all parts except the spleen and alimentary canal, the blood returns to systemic veins, superior or inferior cavae, right auricle, and right ventricle. The blood from the stomach spleen, and intestines however, passes via {through} the portal vein to the liver capillaries and then through the hepatic vein to inferior cava, and so on. Material leaves the blood to be excreted in lungs, kidneys, by the skin (as perspiration) , and elsewhere. New material enters most conspicuously ”

“ The arterial injection can be made through the carotid artery, the systemic venous injection through the femoral vein, and the portal circulation can be filled after opening the abdomen, by injection through the superior mesenteric or splenic veins. Animals prepared in this manner are especially useful for the study of the upper portion of the abdominal cavity and of the peritoneal relations of liver, stomach, spleen, pancreas and duodenum. ”

“ Veins are hollow and round, like pipes, arising from the liver, carrying blood and natural spirits; they feed all the parts. Of these there be two chief, Vena porta and Vena cava, from which the rest are corrivated. That Vena porta is a vein coming from the concave of the liver, and receiving those mesaraical veins, by whom he takes the chylus from the stomach and guts, and conveys it to the liver. The other derives blood from the liver to nourish all the other dispersed members. The branches of that Vena porta are the mesaraical and haemorrhoids. ”

“ The operation of extracting varicose veins is briefly described in the ‘Isagoge’ of Galen. Albucasis describes accurately the different modes of operating upon varices. He says there are two methods of performing the operation with the knife, that is to say, by incision or by extraction. The former method is done by applying a piece of fillet round the upper part of the thigh, and at the inferior part near the knee, and then opening the vein in one, two, or three places, and evacuating the blood in it: the limb is then to be bound up. ”

“ VEINS OF THE TRUNCUS VENA ILIACA COMMUNIS The vena intervertebralis lumbalis, which comes out of the lumbar region, the spinal canal, the lumbo-sacral nerve plexus, and several small venous branches from the lobes of the kidney. It passes dorsalward through the kidney and empties into the iliac vein. There are also communications with the vena intervertebralis thoracica.
The vena renalis magna (Fig. 64, No. 47) forms the main descending vein to the middle and posterior lobes of the kidney. It lies ventrally and mesially on the middle lobe and partly on the inner part of the posterior lobe. ”

“ The distribution of the veins of the rabbit has only a superficial parallelism with arteries. The chief factors of vena cava inferior are the hepatic vein (h.v.) , which receives the liver blood, the renal veins (r.v.) ”

“ In operations involving large vessels, the local conditions which may influence the actions in the veins, appear not to have been fully determined; for while some surgeons regard the tying or cutting of a vein as a serious operation, others are in the habit of doing it without any unusual precaution. In operations upon hæmorrhoidal tumours, the veins involved are of some size, and in two of the instances recorded in the Appendix, a ligature applied to them was followed by purulent deposits. ”

“ In many bodies, however, some degree of careful search requires to be made prior to the full exposure of the vessel in its sheath, in consequence of a considerable quantity of adipose tissue, some lymphatic glands, and many small veins lying in the immediate vicinity of the carotid artery and internal jugular vein. This latter vessel, though usually lying completely concealed by the sterno-mastoid muscle, is frequently to be seen projecting from under its fore part. ”

“ Entrance of Air into Veins—Air Embolism.—This serious, though fortunately rare, accident is apt to occur in the course of operations in the region of the thorax, neck, or axilla, if a large vein is opened and fails to collapse on account of the rigidity of its walls, its incorporation in a dense fascia, or from traction being made upon it. If the wound in a vein is thus held open, the negative pressure during inspiration sucks air into the right side of the heart. ”

“ The process of repair goes on frequently during a continued flow of blood over the part, and sometimes during the constant action of the muscles in the neighbourhood: at other times, an injured vein will be situated immediately in the bend of a joint, and will be subject to be continually bent and extended with the motions of the limb. In the structure of the bones, the veins lie in unyielding channels, and are consequently deprived of the assistance derived from the approximation of their sides, as in soft parts, during the process of reparation. ”

“ It has been shown upon very high authority, that the sides of a vein do not unite after venesection (as has sometimes been presumed to be Mr. Hunter's opinion) ; but that the divided edges only of the vessel are agglutinated by the coagulum, which "serves as a bed to the new membrane." But the case is different, should this first attempt at union fail; the sides of the vessel may then become united, and its cavity for a time obstructed (section iv) . ”

“ The symptoms and consequences of inflammation of the vein have been already detailed. The affection is attended with great pain, and with swelling from effusion into the cellular tissue around the course of the vessel; the integuments are inflamed and tense; sero-purulent secretion soon takes place in the infiltrated cellular tissue, both deep and subcutaneous, followed by sloughing, and separation of the skin from its subjacent connexions; even death of the muscular structure sometimes ensues—the pectoral muscles have been found black and soft. The local treatment must be active. ”

“ This remark I have had opportunities of verifying in cases, where needles have been introduced under varicose veins in the lower extremities, and allowed to remain, with a ligature around them, for ten days or a fortnight. The circulation through the vein will in such cases be obstructed; but, in a year or two, will be found to have become completely re-established. ”

“ The shifting of veins on a small scale is much more common than the larger phenomena of this nature, which are nevertheless of frequent occurrence wherever veins exist. These larger dislocations are known to arise either from the lateral motion or subsidence of the containing parts, the sides of the line of fracture sometimes remaining in contact, and being at others separated by a vein of another description, too well known among miners to need any comment here. ”