Possibly the greatest anatomist of the 19th century, Henle made fundamental contributions to our understanding of human structure, particularly at the microscopic level. Indeed, medical historians consider his contributions to histology on par with Andreas Vesalius's work in gross anatomy.
He provided important insights into the anatomy the lens, retina, exocrine glands, the lacrimal canal, the cochlea & vestibule of the inner ear, and epithelium -- he was the first to describe squamous, cuboidal, columnar, and ciliated epithelial cells. He is best known though for the tubular loops in the kidney that he was first to characterize, known forever hence as the loops of Henle.
He also conducted some of the first physiological investigations of hair development and smooth muscle function in blood vessels.
In his seminal 1840 paper Pathologische Untersuchungen ("Pathological Researches") he was the first to provide a clear pronouncement that particular micro-organisms can cause specific diseases, a concept that his student, Rober Koch paid particular attention to and later expanded upon in his immortal Koch's postulates, sometimes referred to as the Koch-Henle postulates.
Henle's interests and talents extended far beyond the laboratory. He was a politically active liberal, a poet, and an accomplished violinist who included the great composer Felix Mendelssohn as one of his good friends (the very familiar wedding march and wedding recessional melodies are from Mendelssohn's pen).
Henle died from renal sarcoma at age 76.
From the Clendening History of Medicine Library and Museum, University of Kansas Medical Center