X+Ray

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=X-Ray= An **X-Ray** is a shadowy negative of internal sturcters made by pointing electrogmagnetic waves of short wave length at the human body.

How It Works
According to [|HowSuffWorks], a X-Ray machine contains two electrodes. A cathode and an anode are in glass tube within the machine. A cathode is a filament normally found in early flourescent lightbulbs. When the filament is heated electrons fly off of the filament. The anode, a positvely charged flat tungsten disk draws the electrons across the tube. When the electrons from the filament hit the tungsten disk, the tungsten emits x-rays, electromagnetic waves of short wave-length. Denser structures in the body absorb more x-rays than hollow structures, so bones appear as light areas on the x-ray. Organs and fatty-tissues are less dense and absorb less x-rays, appearing as darker areas on the x-ray.



History
X-rays were discovered by a German physicist, Wilhelm Roentgen, in 1895. While performing an experiment with electron beams in a gas discharge tube, a flourescent screen in his lab started glowing in response to electromagnetic radiation even though the tube was covered by a thick cardboard. After this discovery, Roentgen began putting objects between the tube and the screen. The screen continued to glow. He finally tried putting his hand in front of the tube, leaving a projection of the bones in his hands on the screen.

Uses
According to the [|National Library of Medicine], x-rays can be used in mamograms to detect tumors and to check for broken bones or fractures to the skeletal system. The patient is exposed to very little radiation, although over-use can be harmful, like all radiation.