Medical Terminology Daily (MTD) is a blog sponsored by Clinical Anatomy Associates, Inc. as a service to the medical community. We post anatomical, medical or surgical terms, their 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

Jean-Louis Petit

Jean Louis Petit
(1674 – 1750)

French surgeon and anatomist, Jean Louis Petit was born in Paris in on March 13, 1674.  His family rented an apartment at his house to Alexis Littre (1658 – 1726), a French anatomist. Petit became an apprentice of Littre at seven years of age, helping him in the dissections for his lectures and at an early age became the assistant in charge of the anatomic amphitheater.

Because of Petit’s dedication to anatomy and medicine, in 1690 at the age of sixteen, became a disciple of a famous Paris surgeon, Castel.

In 1692, Petit entered the French army and performed surgery in two military campaigns. By 1693 he started delivering lectures and was accepted as a great surgeon, being invited to the most difficult operations.  In 1700 he was appointed Chief Surgeon of the Military School in Paris and in the same year he received the degree of Master of Surgery from the Faculty of Paris.

In 1715 he was made a member of the Royal Academy of Sciences and an honorary member of the Royal Society of London. He was appointed by the King as the first Director General of the Royal Academy of Surgery when it was founded in 1731.

Petit’s written works are of historical importance.  “Traite des Maladies des Os” ( A Treatise on Bone Diseases);  “Traite des Maladies Chirurgicales et des Operation” (A Treatise on Surgical Diseases and their Operations” This last book was published posthumously in 1774. He also published a monograph on hemorrhage, another on lachrymal fistula, and others.

He was one of the first to perform choIecystotomy and mastoidotomy. His original tourniquet design for amputations saved many in the battlefield and the design of the same surgical instrument today has not changed much since its invention by him.

His name is remembered in the lumbar triangle, also called the "triangle of Petit", and the abdominal hernia that can ensue through that area of weakness, the lumbar hernia or "Petit's hernia".

1. “Jean Louis Petit – A Sketch of his Life, Character, and Writings” Hayne, AP San Fran Western Lancet 1875 4: 446-454
2. “Oeuvres compl?tes de Jean-Louis Petit” 1837 Imprimerie de F. Chapoulaud
3. Extraits de l'eloge de Jean-Louis Petit Ius dans Ia seance publique de I' Academie royale de chirurgie du 26 mai 1750” Louis A. Chirurgie 2001: 126 : 475- 81

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Friggatriskaidekaphobia / paraskevidekatriaphobia

: This article was originally titled "[friggatriskaidekaphobia], a word that means "fear of Friday the thirteenth".

It is based on the term [triskaidekaphobia] which means "fear of the number thirteen". Although in modern Greek the number thirteen is pronounced [dekatria] (δεκατρία), the term triskaideka means "three and ten" in older Greek. Add the Greek suffix [φοβία] [phobia] meaning "fear" and you have the word triskaidekaphobia. An alternate spelling is triskadekaphobia

The term [Frigga] refers to a Norse goddess after whom the name for the day Friday originates. Frigga is the wife of Odin and the mother (or stepmother, depending on who interprets old traditions) of Thor.

Reading the book "Complications: Notes from the Life of a Young Surgeon" by Atul Awande. MD (one of the books in my library) I came across a synonym for this concept, the word "paraskevidekatriaphobia" also written as "paraskevideikatriaphobia". The author does not explain the origin or etymology of the term. What he does say is that in the United States, on Friday the 13th, people "perform rituals before leaving the house, call in sick to work, or postpone flights or major purchases, causing businesses to lose $750 million annually". Keep in mind that this book was written in 2002. A simple calculation at shows that by 2022, this corresponds to 1.2 billion dollars!

The origin of the superstition that Friday the 13th is a bad day started on Friday the 13th, 1307. On this date all the Knights Templar were rounded, arrested, accused, tortured, and executed. It is indeed a bad day, but only if you are a member of the Knights Templar!