Cilia are slender, microscopic, hair-like structures or organelles that extend from the surface of nearly all mammalian cells (multiple or single).ource: Amelia Shoemark. ' Motile ' (or moving) cilia are found in the lungs, respiratory tract and middle ear. These cilia have a rhythmic waving or beating motion (see right). They work, for instance, to keep the airways clear of mucus and dirt, allowing us to breathe easily and without irritation.
Share. The visible light spectrum is the section of the electromagnetic radiation spectrum that is visible to the human eye. It ranges in wavelength from approximately 400 nm (4 x 10 -7 m) to 700 nm (7 x 10 -7 m). It is also known as the optical spectrum of light. By Andrew Zimmerman Jones.
Visible light is a small fraction of the entire electromagnetic spectrum with wavelengths ranging from 380 nm (nanometres or 10-9 m) to 740 nm. The whole bandwidth of the spectrum is illustrated in the following image. All the different types of electromagnetic radiation consist of photons of a specific wavelength. All objects that are warmer than their surrounding (that includes all the astronomical objects like stars, nebulae, planets, etc.) emit photons within a certain range of different wavelengths.