They are called the hepatic (liver) and renal (kidneys) portal systems. The hepatic system is important because it collects blood from the intestine and passes it to the liver, the centre for many chemical reactions concerned with the absorption of food into the body and the control of substances… Read More
What is the function of hepatic portal system?
What is the function of the hepatic portal system? Function is to drain blood from digestive viscera, spleen, pancreas, and deliver for processing This regulates nutrients, detox and removes bacteria and other debris. Hepatic Portal Vein bring blood back to liver (located below liver) Gastric Vein drains lesser curvature (medial aspect of stomach)
What does the hepatic portal system bring?
The hepatic portal system is a series of veins that carry blood from the capillaries of the stomach, intestine, spleen, and pancreas to capillaries in the liver. Its main function is to deliver de-oxygenated blood to the liver to be detoxified further before it returns to the heart.
What veins make up the hepatic portal system?
portal vein
- Relations. The bile duct and the gastroduodenal artery lie between the portal vein and the first part of the duodenum, and there it is in front of the vena cava.
- Tributaries. There are only a few direct tributaries of the portal vein. ...
- Branches. ...
- Communications. ...
Does hepatic portal system carry blood to the kidneys?
The hepatic portal vein is one of the most important vein that receives blood from the body and transports it into the liver for filtration and processing. This vein is part of the hepatic portal system that receives all of the blood draining from the abdominal digestive tract, as well as from the pancreas, gallbladder, and spleen. ‘Hepatic’ means of or relating to the liver, therefore the ...
Why is it called hepatic portal system?
The hepatic portal system is so named since it connects capillaries of the intestines and other digestive organs to modified capillaries (hepatic sinusoids) of the liver.
What does hepatic portal mean?
Listen to pronunciation. (heh-PA-tik POR-tul vayn) A blood vessel that carries blood to the liver from the intestines, spleen, pancreas, and gallbladder. Also called portal vein.
What does Portal mean in anatomy?
noun Anatomy. a vascular arrangement in which blood from the capillaries of one organ is transported to the capillaries of another organ by a connecting vein or veins.
Why is the hepatic portal vein called a vein?
The portal vein is not a true vein, which means it does not drain into the heart. Instead, it brings nutrient-rich blood to the liver from the gastrointestinal tract and spleen.
What is unique about the hepatic portal system?
The hepatic portal system is the system of veins comprising the hepatic portal vein and its tributaries. The liver consumes about 20% of total body oxygen when at rest, so the total liver blood flow is quite high. Blood flow to the liver is unique in that it receives both oxygenated and partially deoxygenated blood.
What is portal system in biology?
A portal system is a system in which the veins start and end in capillaries. It delivers nutrient-rich blood to the liver for purification before it is carried to the heart.
What is another name for the portal vein?
For this reason, the portal vein is occasionally called the splenic-mesenteric confluence. Occasionally, the portal vein also directly communicates with the inferior mesenteric vein, although this is highly variable. Other tributaries of the portal vein include the cystic and the left and right gastric veins.
What do you mean by the portal vein and portal system?
The portal vein (PV) is the main vessel of the portal venous system (PVS), which drains the blood from the gastrointestinal tract, gallbladder, pancreas, and spleen to the liver. There are several variants affecting the PV, and quite a number of congenital and acquired pathologies.
What is the difference between hepatic vein and portal vein?
One is the hepatic artery, which brings in oxygen-rich blood from the heart. The other is the portal vein, which delivers blood from your stomach, intestines, and the rest of your digestive system.
How is portal vein different from hepatic vein?
The portal vein wall typically is hyperechoic over a wide range of beam-vessel angles, whereas the hepatic vein wall is hyperechoic only when the incident beam and the vessel are perpendicular.
How is the hepatic portal vein different from other veins?
A vein arises from venules of capillary bed and drains in a larger vein or in the heart. The hepatic portal vein arises from capillary bed of one organ and ends in capillary bed of another organ.
What is the function of the hepatic system?
The hepatic system detoxifies blood, metabolizes glucose, and synthesizes proteins, and is a blood reservoir. The liver and heart are connected through the hepatic artery – which also receives 75% of the blood flow from the spleen, pancreas and stomach.
What is hepatic portal vein and artery?
The portal vein and hepatic arteries form the liver's dual blood supply. Approximately 75% of hepatic blood flow is derived from the portal vein, while the remainder is from the hepatic arteries. Unlike most veins, the portal vein does not drain into the heart.
Do humans have hepatic portal system?
In human anatomy, the hepatic portal system is the system of veins comprising the hepatic portal vein and its tributaries.
What is the hepatic portal system?
The hepatic portal system is the venous system that returns blood from the digestive tract and spleen to the liver (where raw nutrients in blood are processed before the blood returns to the heart). Essentially, it drains the structures supplied ultimately by the celiac (except for the gonads), anterior mesenteric, gastrosplenic, and posterior mesenteric arteries. Thus, the branches of the hepatic portal system closely follow many of the branches of these arteries, and it is convenient to study them following your identification of the arteries. In some specimens the hepatic portal system is injected with yellow latex, which greatly facilitates its study. You may follow its branches in an uninjected specimen, but also briefly examine a shark that has the system injected.
Where is the hepatic portal vein located?
They unite to form the hepatic portal vein near the anterior tip of the dorsal lobe of the pancreas. Recall that the celiac artery splits into its branches very near this point as well.
What is the central core of the villus?
The central core of a villus contains the means by which absorbed nutrients begin their journey from the intestinal epithelium to the liver, where they are either further metabolized or distributed to other parts of the body. The core of a villus is essentially lamina propria tissue that contains a capillary network and a central blind-ending lymphatic channel—a lacteal ( Fig. 12.29). Sugars, amino acids, and simple lipid molecules pass from the enterocytes into the capillaries within the villi. From there, the capillaries empty into a prominent system of veins—the hepatic portal system—that drains the intestines, bringing all of the absorbed nutrients into the liver. As befits a portal system, within the liver the hepatic portal vein then breaks down into a network of smaller veins and ultimately into an extensive system of venous sinusoids that bring the nutrient-rich blood into direct contact with the epithelial cells of the liver (hepatocytes). The hepatocytes are in essence biochemical factories that perform an amazing variety of biochemical functions (Box 12.4 ).
Why are hypophysial portal vessels called hypophysial portal vessels?
5.9) are so called because they transport chemical messengers from one capillary bed (primary capillaries) to a second capillary bed before entering the general circulation . In principle this is identical to the hepatic portal system, which transports substances from the primary bed of capillaries in the intestine and its appendages (e.g., pancreas) to a second bed of capillaries or sinusoids in the liver. Both the primary and the secondary (sinusoids) plexus of capillaries are fenestrated (Fig. 5.7 ), which facilitates the transport of substances across the capillary wall. Hormones released from anterior pituitary cells are transported by pituitary veins into the systemic circulation, by which they are transported to their major target organs, the gonads and the adrenal and thyroid glands.
Which system transports substances from the primary bed of capillaries in the intestine and its appendages to
In principle this is identical to the hepatic portal system , which transports substances from the primary bed of capillaries in the intestine and its appendages (e.g., pancreas) to a second bed of capillaries or sinusoids in the liver.
Where does venous blood enter the liver?
Venous blood rich in nutrients enters the liver from the hepatic portal venous system. The hepatic portal vein drains the digestive tract and efficiently transports metabolic building blocks (sugars and amino acids) directly to the liver, where they are reconstituted into more complex molecules.
Which vein forms the pancreatic artery?
Here it is formed by various tributaries. Among these are the anterior intestinal and the anterior lienogastric veins ( Figure 3.32 ).
The Portal system
A portal system is a system where the veins begin and end in the capillaries and supply deoxygenated blood to the liver for purification before it is transported to the heart.
The Hepatic Portal system
The hepatic portal system is a complex system of hepatic portal veins and their capillaries, also known as the portal vein system. It is the venous system that includes the hepatic portal vein and its tributaries.
Importance of the Hepatic Portal Vein System
The hepatic portal vein carries 75% of the hepatic blood flow and is therefore of critical importance.
Sample Questions
Ques. What is the importance of the hepatic portal system in the circulatory system?
What is portal hypertension?
Portal hypertension is a condition in which the blood pressure of the portal venous system is too high. It is often the result of cirrhosis of the liver.
What is the portal vein?
The hepatic portal vein and its territory. Details. Location. Abdomen. Anatomical terminology. In human anatomy, the hepatic portal system is the system of veins comprising the hepatic portal vein and its tributaries. It is also called the portal venous system (although it is not the only example of a portal venous system) and splanchnic veins, ...
What is the function of the portal vein?
Microscopic section through a small portal vein branch inside the liver (×250 magnified) The portal venous system is responsible for directing blood from parts of the gastrointestinal tract to the liver. Substances absorbed in the small intestine travel first to the liver for processing before continuing to the heart.
How do suppositories bypass the portal vein?
The use of suppositories is a way to partially bypass the portal vein: the upper 1/3 of the rectum is drained into the portal vein while the lower 2/3 are drained into the internal iliac vein that goes directly in the inferior vena cava (thus bypassing the liver).
What happens when the hepatic system breaks down?
The necessity of such a system is demonstrated by what happens when the system breaks down, as seen when advanced hepatic fibrosis in cirrhosis leads to hepatic encephalopathy in the brain owing to the blood being loaded with ammonia and other substances not conducive to brain function.
Where does the hepatic vein drain?
The hepatic vein subsequently drains into the inferior vena cava . The hepatic artery provides 30 to 40% of the oxygen to the liver, while only accounting for 25% of the total liver blood flow. The rest comes from the partially deoxygenated blood from the portal vein. The liver consumes about 20% of the total body oxygen when at rest.
Which vein connects to the portal vein?
The inferior mesenteric vein connects in the majority of people on the splenic vein, but in some people, it is known to connect on the portal vein or the superior mesenteric vein . Roughly, the portal venous system corresponds to areas supplied by the celiac trunk, the superior mesenteric artery, and the inferior mesenteric artery .
What is the portal system?
Portal system is a system of blood vessels that begins and ends in capillaries. Hepatic portal carries nutrients from digestion to the liver to store and metabolize, after a meal.
Where does the hepatic portal vein travel?
The hepatic portal circulation travels from the intestine of the digestive tract to the liver.
Which system divides into portal veins?
endocrine systems. In the second system, the hepatic portal circulation, capillaries originating in the gastrointestinal tract and the spleen merge to form the portal vein, which enters the liver and divides to form portal capillaries.
Why is the hepatic system important?
The hepatic system is important because it collects blood from the intestine and passes it to the liver, the centre for many chemical reactions concerned with the absorption of food into the body and the control of substances… .
Overview
In human anatomy, the hepatic portal system is the system of veins comprising the hepatic portal vein and its tributaries. It is also called the portal venous system (although it is not the only example of a portal venous system) and splanchnic veins, which is not synonymous with hepatic portal system and is imprecise (as it means visceral veins and not necessarily the veins of the abdo…
Structure
Large veins that are considered part of the portal venous system are the:
• Hepatic portal vein
• Splenic vein
• Superior mesenteric vein
• Inferior mesenteric vein
Function
The portal venous system is responsible for directing blood from parts of the gastrointestinal tract to the liver. Substances absorbed in the small intestine travel first to the liver for processing before continuing to the heart. Not all of the gastrointestinal tract is part of this system. The system extends from about the lower portion of the esophagus to the upper part of the anal canal. It also in…
Clinical significance
Portal hypertension is a condition in which the blood pressure of the portal venous system is too high. It is often the result of cirrhosis of the liver.
Many drugs that are absorbed through the GI tract are substantially metabolized by the liver before reaching general circulation. This is known as the first pass effect. As a consequence, certain drugs can only be taken via certain routes. For example, nitroglycerin cannot be swallowed becau…
See also
• Systemic venous system
• Pulmonary venous system
External links
• Hepatic portal system
• Kimball Pages, Hepatic portal system
• VIRTUAL Liver, an interactive liver anatomy tool (Contains rich media; Flash player and Javascript required)