blood vessel

tube or duct of the body containing or circulating blood (artery, vein or capillary)

tubes which transport blood throughout the body

The blood vessels are part of the cardiovascular system and function to transport blood throughout the body. The most important types, arteries and veins, carry blood away from or towards the heart, respectively.
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Blood vessel n. An elastic tubular channel, such as an artery, a vein, a sinus, or a capillary, through which the blood circulates. [more]Blood vessel - Community and Resources

Noun
1. a vessel in which blood circulates
(hypernym) vessel, vas
(hyponym) artery, arteria, arterial blood vessel
(part-holonym) circulatory system, cardiovascular system

Any vessel or canal in which blood circulates in an animal, as an artery or vein.