None of the hepatic veins have valves.

The dose of radiation to the conjunctiva is controlled by the time that the plaque is left in contact with the surface.

In veins or smaller arteries, where flow is not as constant, they are less apparent.

They arise from the substance of the liver, more specifically the central vein of the liver lobule.

In these animals, the left atrium still serves the purpose of collecting blood from the pulmonary veins.

Venous stasis, or venostasis, is a condition of slow blood flow in the veins, usually of the legs.

The most common method of tattooing in modern times is the electric tattoo machine, which inserts ink into the skin via a single needle or a group of needles that are soldered onto a bar, which is attached to an oscillating unit.

Foramina inside the body of humans and other animals typically allow muscles, nerves, arteries, veins, or other structures to connect one part of the body with another.

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While humans, as well as other vertebrates, have a closed cardiovascular system (meaning that the blood never leaves the network of arteries, veins and capillaries), some invertebrate groups have an open cardiovascular system.