Vein veins), not their oxygen content. In addition, deoxygenated blood that is carried from the tissues back to the heart for reoxygenation in the systemic circulation still carries some oxygen, though it is considerably less than that carried by the systemic arteries or pulmonary veins. Although most veins take blood back to the heart, there is an exception. 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. The blood is then drained in the gastrointestinal tract and
Collapsed vein against the plunger of the syringe to check that the needle is in the vein. This will pull the sides of the vein together and, especially if they are inflamed, they may stick together causing the vein to block. Removing the needle too quickly after injecting can have a similar effect. Collapsed veins may never recover. Many smaller veins are created by the body to circulate the blood, but they are not adequate for injections or IVs. Collapsed vein Collapsed veins are a common result of chronic use of intravenous injections. They are particularly common where injecting conditions are less