A hypodermic needle is a very thin, hollow tube with one sharp tip. As one of the most important intravenous inventions in the field of drug administration, it is one of a category of medical tools which pierce the skin, called sharps. It is commonly used with a syringe, a hand-operated device with a plunger, to inject substances into the body or extract fluids from the body. Large-bore hypodermic intervention is especially useful in catastrophic blood loss or treating shock. It was invented by Francis Rynd in 1844.