Smegma is a secretion produced by the sebaceous glands in the foreskin of the penis. Along with loosened epithelial cells, it forms deposits of a whitish mass under the foreskin on the glans penis. If it is not washed off regularly, malodorous microorganisms grow on it and irritate the tissues, which can lead to an inflammation (balanitis). This enhanced SEM shows a small part of a bacterial filter with a deposit of smegma bacteria. Image width: 6.6 micrometers. Magnification: 15,150x, if the image is printed 10 cm wide.