The electromagnetic radiation spectrum can be divided into seven types of wavelengths of light, which are classified according to the decrease in wavelength and the increase in energy and frequency: 1-radio waves, 2-microwaves, 3-infrared light, 4-visible light, 5-ultraviolet, 6-X rays and 7-gamma rays. The atmosphere is not permissible to all types of wavelengths of light, thereby acting as a natural barrier that protects against harmful radiation waves. All the range of visible light can penetrate the Earth's atmosphere, while most radio waves can penetrate through this barrier. Finally, only some wavelengths of infrared and ultraviolet radiation can pass through the atmosphere.
These are the inner folds of the stomach. The folds are pronounced in an empty stomach that is not yet distended by food. They also increase the surface area in which the food is in contact with digestive enzymes produced by the stomach walls.
