1 In 1990, Barack Obama was elected as the first black president of the Harvard Law Review. 2  Obama, who graduated from HLS in 1991, would later represent Illinois in the U.S Senate, and in 2008 would become the 44 th President of the United States, and the first African-American president.
Most cancers in the lung are carcinomas-cancers of epithelial cells. The top pair of images shows the normal epithelium of the bronchi. This photomicrograph is greatly enlarged. The next three pairs of images show three successive stages of abnormal changes in the bronchial epithelium commonly found in smokers.
Types of epithelium: Epithelia are classified according to the number of layers of cells they contain and the shape of the cells. If the cells are arranged in a single layer, the epithelium is called simple; if the cells are arranged in two or more layers, the epithelium is called stratified.ypes of epithelium: Epithelia are classified according to the number of layers of cells they contain and the shape of the cells. If the cells are arranged in a single layer, the epithelium is called simple; if the cells are arranged in two or more layers, the epithelium is called stratified.