#cardinal_vein  any of the major venous channels in primitive adult vertebrates and in embryos of higher vertebrates
  supertype:  vein__vena  a blood vessel that carries blood from the capillaries toward the heart; all veins except the pulmonary carry unaerated blood
  subtype:  anterior_cardinal_vein  a major drainage channel from the cephalic part of the body
  subtype:  posterior_cardinal_vein  a major drainage channel from the caudal part of the body
  subtype:  common_cardinal_vein  the major return channels to the heart; formed by anastomosis of the anterior and posterior cardinal veins

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