A cheek cell, an epithelial cell found in the tissue on the inside lining of the mouth, continually secretes mucus to maintains a moist environment in the mouth. Together with salivary glands that secrete saliva, the cheek cells supply enough moisture in the mouth for enzymes to thrive. This moisture softens food, assists in swallowing and starts digestion.
The epithelial cells in the lining of the mouth are referred to as basal mucosa and divide roughly every 24 hours. They can easily be obtained through a simple swab or a mouth rinse. The cheek cell is very simple, but it contains the entire genetic makeup of the person's body. For this reason, cheek cells are frequently used to establish paternity and other investigations involving DNA. More recently, researchers have discovered that the cheek cell can be used to measure a person's likelihood of having high blood pressure.
A human cheek cell is thin, flat and irregularly shaped and has a large nucleus that contains the DNA. Its plasma membrane helps the cell to maintain suitable temperature while giving it its shape. Since it is selectively permeable, it only allows certain molecules into and out of the cell. Its cytoplasm contains water that dissolves nutrients and enzymes.