Answer
The upper cell layer is composed of flat scale-like cells, but the cells of the deeper layers are cuboid or columnar, and include mitotically active stem cells. As the basal cells proliferate , the daughter cells move towards the surface; near the surface they become flatter and more scale-like , lose their nuclei, and die. Then they disintegrate and flake off in a process called exfoliation. The study of this process is a sub-speciality of histology known as exfoliative cytology.
Work Step by Step
Exfoliated cells can be easily obtained for study by scraping the gingiva (gums) or swabbing the uterine cervix, and preparing smears on microscope slides.. Such smears are usually stained, and the cells examined for abnormalities . This smear technique is commonly used in the search for signs of uterine cancer.
