Tooth enamel overall process of tooth development. Under a microscope, different cellular aggregations are identifiable within the tissues of a developing tooth, including structures known as the enamel organ, dental lamina, and dental papilla. The generally recognized stages of tooth development are the bud stage, cap stage, bell stage, and crown, or calcification, stage. Enamel formation is first seen in the crown stage. Amelogenesis, or enamel formation, occurs after the first establishment of dentin, via cells known as ameloblasts. Human enamel forms at a rate of around 4 μm per day, beginning at the future location of cusps, around the third or
Human skin 20 blood vessels, 60,000 melanocytes, and more than 1,000 nerve endings. The average human skin cell is about 30 micrometers in diameter, but there are variants. A skin cell usually ranges from 25-40 micrometers (squared), depending on a variety of factors. Skin is composed of three primary layers: the epidermis, the dermis and the hypodermis. Epidermis, "epi" coming from the Greek meaning "over" or "upon", is the outermost layer of the skin. It forms the waterproof, protective wrap over the body's surface which also serves as a barrier to infection and is made up of stratified squamous epithelium with an