Endoscope

A tube-like viewing instrument that is inserted into a body cavity to investigate or treat disorders. Endoscopes can be either flexible or rigid, depending on the part of the body to be examined. A flexible fibre-optic endoscope is a bundle of light-transmitting fibres. At the head, it has an eyepiece, steering device, and power source; at the tip, there is a light, a lens, an outlet for air or water, and sometimes a camera that transmits a picture to a screen. Side channels enable various surgical instruments to be passed down the endoscope. A rigid endoscope is a straight tube with a light attached.