The membrane lining various vessels and cavities of the body, such as the pleura (lining the lung), the pericardium (lining the heart), the peritoneum (lining the abdomen and abdominal organs), the lymphatic vessels, blood vessels, and joints. It consists of a fibrous layer covered with thin flat cells, which render the surface perfectly smooth and secrete the fluid for its lubrication.

Cystoscope used for examining the bladder

Percutaneous nephroscope used for examining the interior of the kidney. It is passed into the pelvis of the kidney through a track from the surface of the skin, made with a needle and guide wire. Instruments can be passed through the nephroscope under direct vision to remove calculi.