Medical Terminology Daily (MTD) is a blog sponsored by Clinical Anatomy Associates, Inc. as a service to the medical community, medical students, and the medical industry. We will post a workweek daily medical or surgical term, its meaning and usage, as well as biographical notes on anatomists, surgeons, and researchers through the ages. Be warned that some of the images used depict human anatomical specimens.

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A Moment in History

Antoine Louis

French surgeon, anatomist, and physiologist. Following his medical studies and a long career as a physiologist, Antoine Louis was named Permanent Secretary of the Royal French Academy of Surgery. His other titles were those of Professor of the Royal Academy, Consultant Surgeon of the Armies of the King, member of the Royal Society of Sciences of Montpellier, Inspector of the Royal Military Hospitals, and Doctor in Law of the University of Paris. As a member of these academies Louis was instrumental in the design and construction of the guillotine. Initially called the "Louisette", this device was later named after another French physician in the same committee, Dr. Joseph-Ignace Guillotin.

Antoine Louis' name is better know to history as the eponymic origin of the "sternal angle" also know as the "Angle of Louis" and synonymously (probably by misspelling or translation) the "angle of Lewis", and "angle of Ludwig". This anatomical landmark is extremely important as it serves as a superficial landmark for important anatomical occurrences (click here).

As a point of controversy, there are some that contest the history of this eponym adjudicating it to Pierre Charles Alexander Louis (1787-1872), another French physician dedicated to the study of tuberculosis.

1. Srickland, N; Strickland A Angle of Louis, More Than Meets the Eye. MedTalks:
2. Ramana, R. K., Sanagala, T. and Lichtenberg, R. (2006), A New Angle on the Angle of Louis. Congestive Heart Failure, 12: 197–199
. "The origin of Medical Terms" Skinner, HA; 1970

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Friedrich Gustav Jakob Henle

This article is part of the series "A Moment in History" where we honor those who have contributed to the growth of medical knowledge in the areas of anatomy, medicine, surgery, and medical research.To search all the articles in this series, click here.

Friedrich Gustav Jakob Henle (1809 -1885) German physician, anatomist, histologist, and physiologist. Born in  the city F?rth, Henle entered the University of Bonn and studied anatomy with Johannes Muller (1801 – 1859), a professor of anatomy and histology. Henle dedicated his efforts to scientific research, and became the managing editor of the journal “Archives of Anatomy, Physiology, and Scientific Medicine” founded by Muller.

Henle’s career in Berlin suffered after he was arrested for 40 days in jail, because of his past membership in a radical liberal and nationalistic student fraternity, the Burschenschaften. He transferred from Berlin to Zurich where he founded the School of Rational Medicine.

Among his publications, the “Allgemeine Anatomie “(1841) is considered the first treatise on microscopic histology. Also, his book “Handbuch der systematischen Anatomie des Menschen” (Handbook of Human Systematic Anatomy) is a great anatomy book with good illustrations.

Henle moved from Zurich to Heidelberg, and from there to G?ttingen, where he accepted the position of Professor of Anatomy. He stayed at G?ttingen until his death in 1885.

Friedrich Gustav Jakob Henle
Original image courtesy of ihm.nlm.nih.gov/
Henle’s many remembered contributions are mostly in the area of histology. His name is found in many eponyms. The eponym most associated with his name is “Henle’s loop”, part of the tubular component of a nephron.

• Crypts of Henle: Microscopic pockets located in the conjunctiva of the eye
• Henle's fissure: Fibrous tissue between the cardiac muscle fibers.
• Henle's ampulla: Ampulla of the uterine (Fallopian) tube
• Henle's layer: Outer layer of cells of root sheath of a hair follicle.
• Henle's ligament (tendon): Tendon of the transversus abdominis muscle.
• Henle's membrane: The layer forming the inner boundary of the choroid of the eye

1. "The Origin of Medical Terms" Skinner, HA 1970 Hafner Publishing Co.
2. “The Man Behind the Eponym Jacob Henle: Henle’s Layer of the Internal Root Sheath” Steffen C. Am J Dermatopath (2001) 23(6): 549–551
3. “The life of Jacob Henle” Robinson A Medical Life Co. 1921