In the circulatory system of animals, a portal venous system occurs when a capillary bed drains into another capillary bed through veins. Both capillary beds and the blood vessels that connect them are considered part of the portal venous system. In human anatomy, the hepatic portal system is the system of veins that comprises the hepatic portal vein and its tributaries. ... For transport in plants, see Vascular tissue. ... This article or section does not cite its references or sources. ... In the circulatory system, a vein is a blood vessel that carries blood toward the heart. ... f you all The blood vessels are part of the circulatory system and function to transport blood throughout the body. ...

They are relatively uncommon as the majority of capillary beds drain into the heart, not into another capillary bed. Portal venous systems are considered venous because the blood vessels that join the two capillary beds are either veins or venules. The heart and lungs, from an older edition of Grays Anatomy. ... In the circulatory system, a vein is a blood vessel that carries blood toward the heart. ... A venule is a small blood vessel that allows deoxygenated blood to return from the capillary beds to the larger blood vessels called veins. ...

Examples of such systems include the hepatic portal system and the hypophyseal portal system. Unqualified, "portal venous system" often refers to the hepatic portal system. For this reason, "portal vein" most commonly refers to the hepatic portal vein. In human anatomy, the hepatic portal system is the system of veins that comprises the hepatic portal vein and its tributaries. ... The hypophyseal portal system is the system of blood vessels that links the hypothalamus and the anterior pituitary. ... The portal vein is a major vein in the human body draining blood from the digestive system and its associated glands. ...