Hen·le \ˈhen-lə\ , Friedrich Gustav Jacob (1809–1885), German anatomist and histologist. One of medicine's great anatomists, Henle influenced the development of microscopic anatomy. In 1841 he published the first systematic treatise on histology. He also published the first descriptions of the structure and distribution of human epithelial tissue and of the minute structure of the eye and brain. In the field of pathology he published (1841–53) a two-volume handbook that described diseased organs in relation to their normal physiological functions. This work ushered in the age of modern pathology. The loop of Henle was described in 1862 and the sheath of Henle in 1871.