Umbilical cord carries oxygenated, nutrient-rich blood to the fetus, and two arteries that carry deoxygenated, nutrient-depleted blood away. Occasionally, only two vessels (one vein and one artery) are present in the umbilical cord. This is sometimes related to fetal abnormalities, but it may also occur without accompanying problems. It is unusual for a vein to carry oxygenated blood and for arteries to carry deoxygenated blood (the only other examples being the pulmonary veins and arteries, connecting the lungs to the heart). However, this naming convention reflects the fact that the umbilical vein carries blood towards the fetus's heart, while the umbilical arteries
Experiments in the Revival of Organisms is shown being isolated from a body; four tubes connected are then connected to the organ. Using an apparatus, the heart beats in the same manner as if it were in a living organism. The film then shows a lung in a tray, which is operated by bellows that oxygenate the blood. Following the lung scene, the audience is then shown a heart-lung machine, composed of a pair of diaphragm linear pumps, venous and arterial, exchanging oxygen with a water reservoir. It is then seen supplying a canine head with oxygenated blood. The head is presented with external stimuli, which