1 All Physician Training licenses expire on August 31, 2015, are good for three years, and can only renew once (for a total of six years). 2  All Physician Assistant licenses expire on January 31 of even-numbered years.  All Anesthesiologist Assistant licenses expire on January 31 of even-numbered years.
The epidermis is the uppermost or epithelial layer of the skin. It acts as a physical barrier, preventing loss of water from the body, and preventing entry of substances and organisms into the body. Its thickness varies according to body site. The epidermis consists of stratified squamous epithelium.
Name the four types of cells found in the epidermis. Keratinocytes, Langerhans cells or epidermal dendritic cells, Merkel cells or tactile cells and melanocytes. Keratinocytes are most abundant. A Merkel cell or a tactile cell is connected to neurons and senses touch in the skin. The Merkel cell is found in the stratum basale.