The inferior mesenteric vein and the superior mesenteric vein run alongside their corresponding arteries. The inferior mesenteric vein returns blood from the rectum and colon. Both veins merges with the splenic vein to form the portalvein. Research Mesenteric Vein
Portal hypertension also known as renovascular hypertension is an increased blood pressure in the portal system caused by a blockage in the liver's blood supply, often linked to alcoholic cirrhosis. It results in the spleen getting larger, increased blood pressure, and varicose veins of the esophagus. Research Portal Hypertension
The portal vein is a large vein (a little over eight centimeters in length) responsible for carrying the oxygen and nutrient poor blood from the organs of the abdomen to the liver, where wastes will be eliminated. The portal vein enters the underside of the liver and divides into a network of capillaries. The capillaries then reconverge and form the hepatic veins that carry the blood to the inferior vena cava. The veins of the liver are relatively large to accommodate the great volume of blood passing through it. The liver receives 28% of the body's total cardiac output of blood, which equates to 1.4 liters of blood circulating through an average adult at rest every minute. Research Portal Vein
The rectum is the lowest portion of the large intestine, terminating at the anus. The rectum is S- shaped, about 22 cm long, and is formed of muscle layers similar to those elsewhere in the intestinal tract. The lower end of the rectum is funnel-shaped and terminates in the analcanal which is lined with a special form of skin. The rectum is 'slung' in the bottom of the pelvis between the levator animuscles. Below this level and around the analcanal is a strong sphincter of voluntary muscle - the external sphincter. The internal sphincter is the thickened lower end of the involuntary rectal muscle. Stretching or weakness of the levator ani muscle, or nervous conditions causing paralysis of this or the external sphincter allow the rectum to drop. The lining mucousmembrane is then 'prolapsed'. On either side of the analcanal below the levator ani muscle is a space containing fat - the ischio-rectal fossa. This is sometimes the seat of infection and abscessformation.
The analcanal has arteries and veins from the systemic circulation coming from the perineum and buttocks. The arteries join with the branches of the inferior mesenteric artery while the veins join with the tributaries of the portalvein which drain the rectum. If the portal veins are blocked or compressed (as in extreme constipation or in more serious disorders which affect the liver, such as cirrhosis) the haemorrhoidal veins become dilated or 'varicose'. These varicosities around and inside the analcanal immediately underneath the lining membrane are called ' piles' or haemorrhoids. Sometimes during strain at stool the veins are temporarily distended and one of them bursts, producing either brisk haemorrhage or a perianal haematoma (a form of external ' pile'). The rectum is normally empty except immediately before defaecation. The passage of the faecal mass from the colon into the rectum produces the desire to evacuate. If the rectum is insensitive, no such desire occurs, and extreme constipation arises. Research Rectum
The spleen is a solid organ lying between the left wall of the stomach and the diaphragm, protected by the lower ribs and held in position by its capsule which is formed of peritoneum. Its very large artery comes almost directly from the aorta and its vein is one of the main tributaries of the portal system. The spleen has many functions which are known and probably others which are not known. It contains smooth muscle and is capable of contracting. It has a sponge-like structure in which the sinuses or spaces of the sponge are filled with blood. By its power of contraction it is able to expel into the circulation a large amount of this reserve blood, to meet sudden demands such as may be produced by shock or haemorrhage. In addition to this reservoir function, the spleen is the 'headquarters' of the reticulo-endothelial system. Cells of this system are found in various parts of the body, the liver, lymph glands and bonemarrow. The function of the reticulo- endotheliai system with its macrophage cells is to deal with foreign particles which circulate in the blood or gain entrance to the tissues, such as bacteria, viruses and other tissue cells. Red blood cells are being continuously destroyed in the spleen. It is probable that antibodies against disease are also produced by the reticulo-endothelial system and by the masses of lymphatic tissue to be found in the spleen. Research Spleen
The splenic vein arises from five or six branches which return blood from the spleen. The splenic vein merges with the superior mesenteric vein to form the portalvein. Research Splenic Vein
iPlanet Portal Server provides all of the membership management, personalization, aggregation, security and integration services needed to quickly deploy demanding e-commerce portals. By building on the iPlanet Portal Server platform, companies can roll out highly scalable business-to- business (B2B), business-to-customer (B2C) and business-to-employee (B2E) portals quickly, even plugging in products from other portal software vendors in the process, including Actuate, E. piphany, grapeVINE, Hyperion, Interwoven, iSyndicate, Lucent Technologies Enterprise Networks Group, Macromedia, NetGenesis, and Net Perceptions. The iPlanet Portal Server, for example, is tightly integrated with GrapeVINE's Compass Server, offering additional web indexing, collaborative filtering and other knowledge management functionality for enterprise information portals. Research iPlanet Portal Server
Otherworld (Y Mabinogi) is a part-animated adventure starring Ioan Gruffudd, Daniel Evans, Jenny Livsey, Matthew Rhys, Sue Jones-Davies, Peter Gruffydd, Robert Gwyndaf, Mali Harries and Philip Madoc in a story based upon the Welsh myths of Y Mabinogi (The Mabinogion) about three troubled teenagers who discover a portal in the ocean and decide to try and enter it themselves and find themselves in the mythical land of Otherworld. Otherworld was directed by Derek W Hayes in 2003. Research Otherworld
Abbreviations
Research Mesenteric Vein
