the medical procedure for drawing a sample of venous blood into a vacuum tube is known as
Venipuncture In medicine, venipuncture or venepuncture is the process of obtaining intravenous access for the purpose of intravenous therapy or for blood sampling of venous blood. In healthcare, this procedure is performed by medical laboratory scientists, medical practitioners, some EMTs, paramedics, phlebotomists, dialysis technicians, and other nursing staff.[1] In veterinary medicine, the procedure is performed by veterinarians and veterinary technicians.
Inferior vena cava The inferior vena cava (or IVC) (Latin: vena, "vein", cavus, "hollow") is a large vein that carries deoxygenated blood from the lower and middle body into the right atrium of the heart. Its walls are rigid and has valves so the blood does not flow down via gravity. It is formed by the joining of the right and the left common iliac veins, usually at the level of the fifth lumbar vertebra.