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.

Click on the link below to subscribe to the MTD newsletter. If you think an article could be interesting to somebody else, click on the mail link at the top of each article to forward it. 

You are welcome to submit questions and suggestions using our "Contact Us" form. The information on this blog follows the terms on our "Privacy and Security Statement"  and cannot be construed as medical guidance or instructions for treatment. 

We have 63 guests and no members online

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

 "Clinical Anatomy Associates, Inc., and the contributors of "Medical Terminology Daily" wish to thank all individuals who donate their bodies and tissues for the advancement of education and research”.

Click here for more information

abebooks banner

bookplateink banner


Nodules of Arantius

The eponymic nodules (or nodes) of Arantius are thickenings of the tunica intima layer covering the ventricular aspect of the leaflets of the aortic valve, also known as the ventricularis layer (see blue arrows in the accompanying image). The thickening happens at the point of coaptation of all three leaflets. The shape and size of these growths varies from person to person and with age. The proper name for these structures is “nodes of the semilunar cusps” or “noduli valvularium semilunarium valvae aortae” in Latin

The portion of the leaflet proximal to the node of Arantius is the load-bearing portion and the portion of the leaflet distal to the node of Arantius is non-functional and is known as the “lunule”

Hypertrophy of the node of Arantius is not common, but when present and excessive it can lead to aortic valve dysfunction and insufficiency.

Aortic root of the ascending aorta open by dissection. The blue arrows show the nodes of Aranttius
Aortic root open. Click on the image for a larger version.
These excrescences of the valve leaflets are named after Giulio Cesare Aranzio (1530 – 1589), an Italian anatomist better known by his Latinized name Arantius.

Although most anatomists and surgeons use the same eponym for the excrescences of the pulmonary valve, those should be called the “nodes of Morgagni” after Giovanni Batista Morgagni (1682 - 1771) or "Noduli valvularum semilunarium valvae trunci pulmonalis" in Latin

1. “The surface anatomy of the human aortic valve as revealed by scanning electron microscopy.” Hurle, JM et al  Anat Embryol (Berl). 1985;172(1):61-7
2. “Hypertrophy of nodules of Arantius and aortic insufficiency: pathophysiology and repair.” Shapira, N et al Ann Thorac Surg. 1991 Jun;51(6):969-72
3. "The origin of Medical Terms" Skinner, AH, 1970
4. "Terminologia Anatomica: International Anatomical Terminology (FCAT)" Thieme, 1998
5. "Tratado de Anatomia Humana" Testut et Latarjet 8th Ed. 1931 Salvat Editores, Spain 
Image property of: CAA.Inc.Photographer: D.M. Klein