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.
Abstract. The epidermis is the protective outer layer of clonally related cells covering all plant organs. It is composed of a number of specialised cell types which differentiate from the basal epidermal cell in adaptively significant frequencies and patterns.lant epidermis fulfils a basic protective function, but specialised cells within the epidermis have specific roles. The aerial epidermis originates in the shoot apical meristem, the root epidermis in the root apical meristem and the seedling epidermis arises by isolation of the outer layer during embryogenesis.