portal vein

Examples of portal vein in the following topics:

• Blood Supply to the Liver

  • In the hepatic portal system, the liver receives a dual blood supply from the hepatic portal vein and hepatic arteries.
  • In the hepatic portal system, the liver receives a dual blood supply from the hepatic portal vein and hepatic arteries.
  • Supplying approximately 75% of the liver's blood supply, the hepatic portal vein carries venous blood drained from the spleen, gastrointestinal tract and its associated organs .
  • Oxygen is provided from both sources; approximately half of the liver's oxygen demand is met by the hepatic portal vein, and half is met by the hepatic arteries.
  • The central veins coalesce into hepatic veins, which collects blood leaving the liver and bring it to the heart.

• Hepatic Portal Circulation

  • The hepatic portal system is the system of veins comprising the hepatic portal vein and its tributaries.
  • The hepatic portal vein supplies about 75% of the blood the liver requires, with the other 25% supplied by the hepatic artery.
  • Blood from the hepatic artery is oxygenated but nutrient-poor compared to that supplied by the hepatic portal vein.
  • Since blood received from the hepatic portal vein may be contaminated with pathogens such as bacteria, the liver is rich in specialized immune cells called Kupffer cells that detect and destroy foreign organisms.
  • Following processing, blood collects in a central vein that drains into the hepatic vein and finally the inferior vena cava.

• Veins

  • Although most veins take blood back to the heart, portal veins carry blood between capillary beds.
  • For example, the hepatic portal vein takes blood from the capillary beds in the digestive tract and transports it to the capillary beds in the liver.
  • Since this is an important function in mammals, damage to the hepatic portal vein can be dangerous.
  • Blood clotting in the hepatic portal vein can cause portal hypertension, which results in a decrease of blood fluid to the liver.
  • Communicating veins - Communicating veins (or perforator veins) directly connect superficial veins to deep veins.

• Principal Veins

  • Deep veins are often of larger caliber than superficial veins and carry the majority of the blood within the circulatory system.
  • Communicating veins, or perforator veins if they pass through a large muscle mass, directly connect superficial and direct veins.
  • There are four pulmonary veins, two from each lung, each of which forms from three to four bronchial veins.
  • The hepatic portal vein carries blood from the gastrointestinal tract to the liver.
  • The portal vein is often described as a false vein because it conducts blood between capillary networks rather than between a capillary network and the heart.

• Anatomy of the Liver and Gallbladder

  • It is connected to two large blood vessels, the hepatic artery and the portal vein.
  • The hepatic artery carries blood from the aorta to the liver, whereas the portal vein carries blood containing digested nutrients from the entire gastrointestinal tract and also from the spleen and pancreas to the liver.

• The Liver and Gallbladder

  • The liver is supplied by two main blood vessels on its right lobe: the hepatic artery and the portal vein.The portal vein brings venous blood from the spleen, pancreas, and small intestine so that the liver can process the nutrients and byproducts of food digestion.

• Transport of Hormones

  • Some endocrine glands secrete into a portal system rather than the systemic circulation that allows for the direct targeting of hormones.
  • For example, hormones secreted by the pancreas pass into the hepatic portal vein that transports them directly to the liver.

• Venous Blood Pressure

  • Venous pressure is the vascular pressure in a vein or the atria of the heart.
  • Portal venous pressure or the blood pressure in the portal vein.
  • In addition, veins can easily distend or stretch.
  • The smooth muscles surrounding the veins become slack and the veins fill with the majority of the blood in the body, keeping blood away from the brain and causing unconsciousness.
  • Veins differ from arteries in structure and function; arteries are more muscular than veins, while veins are often closer to the skin and contain valves to help keep blood flowing toward the heart.

• Veins of the Upper Limbs

  • The major deep veins of the arm are the radial and ulnar veins, which run along the length of their respective bones and merge at the elbow to form the paired brachial vein.
  • The major superficial veins of the upper limb are the cephalic, median cubital and basilic veins.
  • The basilic vein follows a similar path but is located medially to the cephalic vein.
  • At the shoulder, the basilic vein passes deep into the arm and merges with the brachial veins to form the axillary vein, to which the cephaliac vein merges, forming the subclavian vein.
  • The deep veins are shown in blue.

• Veins of the Head and Neck

  • The superficial external jugular vein is formed from the retromandibular vein and the posterior auricular vein at a point adjacent to the mandible.
  • The external jugular vein passes down the neck and underneath the clavicle before draining into the subclavian vein.
  • Upon exiting the neck, the internal jugular vein merges with the subclavian vein to form the brachiocephalic vein.
  • Additional veins such as the occipital, deep cervical, and thyroid veins drain directly into the brachiocephalic vein.
  • The veins of head and neck are labeled in blue, with an arrow pointing to the auricular vein.