Cervical cancer cell, coloured scanning electron micrograph (SEM). The cervix is the lower part of the womb, also called the neck of the womb, and comprises part of the woman's reproductive system. Cervical cancer is more common in younger women. One of the main causes of cervical cancer is a persistent infection of certain types of human papilloma virus (HPV). The cell in this image is displaying a process known as blebbing. Blebbing is a bulge or protrusion of the plasma membrane of the cell which is visible on the cell surface. Blebbing is often seen during programmed cell death (apoptosis) or may be seen when a cell is undergoing physical or chemical stresses. It also has important functions in cellular processes such as cell locomotion, playing a role in cell migration. Magnification: x2500 when printed at 10 cm wide.