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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-cis- / incision

[UPDATED] This is a medical term derived from the Latin [incisus] or [incisura], meaning "to cut". The Greek word [Τομή] (tomí) from which the suffixes [-otome], or [-otomy] derive, have a similar meaning.

The root term is [-cis-] and uses of this term include:

Incision : "To cut in" • Incisive: Something that "cuts in"

Incisor: Refers to a type of tooth that has a "cutting in" action

Excision: The prefix [ex-] means "out" or "outside". To cut out, or to extirpate. See the meaning of the suffix [-ectomy] here

Circumcision: The prefix [circum-] means "around", or "in a circle". To cut around (in a circle)

Note: Google Translate includes the symbol (?). Clicking on it will allow you to hear the pronunciation of the word.


Lateral view - Human embryo about eight and a half weeks old. Public domain
Lateral view - Human embryo about
eight and a half weeks old

(UPDATED) The term [ventral] arises from the Latin word [venter] and the root term [ventr-] meaning "belly" or "sac". The adjective [ventral] means "towards the front" , or "towards the belly side of the body". The term ventral therefore means "abdomen".

Many use the term [ventral] synonymously with "anterior"; although this is technically correct, the proper term to use when referring to the patient in the anatomical position should be "anterior". In embryology, since the embryo is curved, most of the anterior aspect of the embryo looks towards the abdomen, ergo ventral.

A ventral hernia is any herniation that occurs in the anterior aspect of the abdomen, including Spigelian hernias, omphaloceles, etc.

Other terms that arise from the same root term are [ventricle], meaning "little belly", or "little sac", and [ventricular], meaning "pertaining to a ventricle".

Note: A comment from my friend Dr. Elizabeth Murray

"My understanding of "anterior" means "in the direction of movement" for any given organism (and "posterior" means opposite the direction of movement for an organism). Thus, ventral does not ever change for any creature (vertebrate or even invertebrate), as it refers to a body part/surface.  But when considering two-legged and four-legged (or finned) creatures, you see the differences:  Ventral = anterior in us, but in a dog or fish ventral = inferior.

Ventral/dorsal refer to belly/back in any organism, and cranial/caudal refer to head-end and tail-end in any organism -- those four terms refer to body parts.  However, anterior/posterior refer to the way an organism moves in space, and superior/inferior refer to an organism's relationship to the earth/pull of gravity."

An interesting side note: The word [ventriloquist] arises from the root term [-ventri-] from the Latin [venter] and the suffix [-loquist], from the Latin [loquos] and [locutus], meaning "to speak", or "someone who speaks". The term [ventriloquist] means then "someone who speaks from the abdomen (or stomach)". We now know that this is not so, but that is what most people think a ventriloquist does!

1 "Tratado de Anatomia Humana" Testut et Latarjet 8 Ed. 1931 Salvat Editores, Spain
2. "Anatomy of the Human Body" Henry Gray 1918. Philadelphia: Lea & Febiger
Image modified by CAA, Inc. Original image by Henry Vandyke Carter, MD., courtesy of


Right homonymous superior quadrantanopia
Right homonymous superior quadrantanopia

[Quadrant]-[an-[opia ] The root “quadrant” is based on the Latin "Quadri" meaning "four" and “Quarto”, meaning one fourth. The suffix anopia is composite: “an” meaning “without or absence of”; and opia (or “opsia”) relate to vision, based on the Greek word “οπτασία”  (optasía) meaning “sight”.  Literally, the term quadrantanopia (or quadrantanopsia) means “absence of sight in a quadrant”.

It can be associated with a lesion of an optic radiation of the internal capsule. While quadrantanopia can be caused by lesions in the temporal and parietal lobes of the brain, it is most commonly associated with lesions in the occipital lobe.

What is interesting are the terms “homonymous” and “heteronymous” used to describe variants of quadrantanopia. Each eye has four quadrants and two visual fields, right and left.  A homonymous quadrantanopia means that the patient has lost the vision of a quadrant in the same field in each eye (right-right or left-left), heteronymous means that the patient has lost the vision of a quadrant in the opposite field of each eye (right-left or left-right).

The fact is that the term homonymous means “same name” not same side, and the word heteronymous means “different name”, from the Greek “όνομα” “nym” meaning name. For further confirmation, try finding the meaning of synonym, antonym, acronym, patronymic, etc.

1. "The Origin of Medical Terms" Skinner, HA 1970 Hafner Publishing Co.
. "Medical Meanings - A Glossary of Word Origins" Haubrich, WD. ACP Philadelphia
3. "Dorlands's Illustrated Medical Dictionary" 26th Ed. W.B. Saunders 1994

Note: Google Translate includes the symbol (?). Clicking on it will allow you to hear the pronunciation of the word.
Image courtesy of Mudsk, CC0, via Wikimedia Commons.

XLIII Congreso Chileno de Anatomía - 2023

I had the honor of being invited to participate in the 53rd Annual Chilean Meeting of Anatomy (XLIII Congreso Chileno de Anatomía) which was held in conjunction with the 1st Latin American Congress of Clinical Morphology (Primer Congreso Latinoamericano de Morfología Clínica). Along with these meetings were two symposia: The First Joint Symposium of Chilean/Korean Anatomists and the First Joint Chilean - IFAA-FIPAE Symposium (International Federation of Associations of Anatomists - Federative International Program for Anatomy Education).

Universidad de Los Andes, Chile
Universidad de Los Andes, Chile

This meeting was held on November 11- 14, 2023 and was hosted by the University of Los Andes (Universidad de Los Andes), a Chilean institution of private higher education that offers careers and postgraduate programs in different areas of knowledge including Education, Engineering, Nursing, Obstetrics, Medicine, Psychology, Law. etc. Their campus is located on the slopes of the beautiful Andes mountains overlooking the city of Santiago, Chile.

The image shows the Main Library of the University, where the meeting was held.

On November 9 and 10, the days leading to the meeting, there were six Postgraduate Courses, from anatomy to radiology and surgical reconstruction. There were two that I would like to highlight. The first one  was a workshop "Mastering Anatomical Radiology with  IMAIOS", where one of the instructors was my good friend Dr. Cristian Uribe, who was one of the Meeting organizers. Dr. Uribe is one of the contributors to Medical Terminology Daily.

The second one was a "Workshop on Art & Science: A Theoretical-Practical Course on Anatomical Illustration". This course was directed by my good friend, Dr. Carlos Machado, world-renown medical illustrator, physician, and anatomist, editor of Netter's Atlas of Anatomy. Along with him two professors, Drs. Daniel Casanova and Valentina Cerda.

Nov. 11, 2023 Meeting opening
Nov. 11, 2023 Meeting opening

The Meeting was officially opened by Dr. Juan Carlos Lopez, Director of the Morphology Department of the Los Andes University. This was followed by a presentation on "The Role of the Placenta on the Modulation of Human Potential" by Dr. Sebastian Illanes. On the picture, from left to right, Dr. Jens Wasche (Germany), Dra. Valentina Cerda (Chile), Dr. Carlos Machado (Brazil/USA), me (Chile/USA), and Dr. Andres Riveros Valdes (Chile), a good friend and anatomist. Dr. Riveros is the President of the LatinAmerican Meeting on Clinical Morphology.

There were so many great presentations in this meeting! I think the attendees will agree with me that the conference by Dr. Carlos Machado on "The Art of Learning and Teaching Anatomy with Art" was one of the highlights of the Meeting. In his presentation Dr. Machado shared some of his early drawings and his career in Medicine and Medical Illustration, how he has used art to show patient pathology, and most important, the work and dedication that is required when developing a single image that will later become part of the Anatomy Atlases with which he collaborates. 

Dr. Carlos Machado
Dr. Carlos Machado

The image above shows Dr. Machado during his presentation. On the screen an anatomical image he drew when he was 12 year old!.

Dr. Carlos Machado
Dr. Carlos Machado

Dr. Cristian Uribe
Dr. Cristian Uribe

Poster presentations during a coffee break
Poster presentations during a coffee break

The meeting was also geared toward morphology students of different careers including Veterinary, Nursing, Dental School, and Medicine. The students presented their research posters during the coffee breaks. There were very high-quality and in-depth research, including the first osteology atlas of the Chilean flamingo (Phoenicopterus chilensis).  I had interesting discussions on Latin terminology with these students.

There were extremely interesting topics throughout the week, including liver anatomy and liver transplant, ethics, philosophy, body donation, etc.

My presentation was based on the conference I delivered in May 2023 at the University of Antwerp, Belgium. Since the Belgium conference was delivered to a group of Andreas Vesalius experts, this one included much more information on Andreas Vesalius, his work, and additional information on printing techniques circa 1550.

Dr. Miranda during his presentation at the XLIII  Anatomy Meeting in Chile
Dr. Miranda during his presentation at the
XLIII  Anatomy Meeting in Chile

The presentation added information on the history of the woodblocks used to print the 1543 Fabrica, the 1555 Fabrica, as well as other books that include the 1925 "The Iconography of Andreas Vesalius" by M.H. Spellman, and the 1934 Icones Anatomicæ.

The included picture was taken towards the end of my presentation where with the help of Dr. Uribe we unveiled Giovanni Paolo Mascagni's (1755-1815) work. At the center is a life-size copy of one of the pages of his book "Anatomiæ Universæ Icones", published in 9 installments between 1823 and 1832. It is important to note that each page of this book was hand-colored by Antonio Serantoni (1780-1837), thus the time it took to print and publish this book.

Mascagni's book, the largest book ever printed, shows in separate pages one third of a larger, life-size individual. Because of the rarity and value of this magnificent work, it cannot be cut and pasted.There are 16 know copies of Mascagni's anatomical opus magnus in the world, one of them at the University of Cincinnati, Ohio. USA.

With the help of Mr. Gino Pasi curator of the Henry Winkler Center for the History of the Health Professions, and the help of Mrs. Samantha Scheck, graphic designer, we measured and scanned some pages of the "Anatomiæ Universæ Icones", cleaned the background (no changes were done to the image itself) and pasted them digitally. The result is a life-size male 5.9 ft tall (1,75 mt). The images are incredible, and having traveled back and forth to Belgium and Chile, they are now part of my personal library.

Once again, my thanks to my old and new friends for making my stay so interesting, both personally and professionally. My thanks to the organizers of these meetings and symposia:

Dr. Juan Carlos López Navarro
President XLIII Chilean Anatomy Meeting
Director Morphology Department - Universidad de Los Andes

Dr. Andrés Riveros Valdés
President I Latin American Clinical Morphology Meeting
Professor - Universidad San Sebastián

Dra. Viviana Toro Ibacache
President Scientific Committee
Professor - Universidad de Chile

Dr. Emilio Farfán Cabello
President Chilean Anatomy Society
Professor - Pontificia Universidad Católica de Chile


Chest X-Ray - dextrocardia
Chest X-Ray - dextrocardia

Normally, the heart is a midline structure found just posterior to the sternum where 35-40% of the heart mass in the right side of the thorax (chest), and the rest (60-65%) is in the left side of the thorax. In this normal condition the apex of the heart faces slightly inferior and to the left. In fact, there are many books and websites that state (wrongly) that the heart is normally in the “left side of the chest”.

If the above mentioned situation is reversed, we are in the presence of dextrocardia, that is, the heart is still in the midline, but most of the mass of the heart is in the right side of the thorax, and the apex points inferiorly and to the right.

The word dextrocardia is a derivate of the Latin [dexter], meaning “right”, and the Greek term [kardia], meaning “heart”. The word dextrocardia literally means “right-sided heart”.

Dextrocardia is a congenital condition, can be completely asymptomatic and present as an isolated condition. It can also be part of a complex genetic condition called “situs inversus” where the whole body is a mirror image of itself and all organs, including the heart are mirrored. A complete situs inversus is rare, but when present it usually does not cause problems.

The problems start when only part of the body and organs are reversed and others are not, causing an incredible number of potential anatomical variations and associated problems.

The prevalence of dextrocardia is about 1 in 12,00 pregnancies. The reported incidence is about 0.22%. Depending on the situation, dextrocardia can present with additional cardiac congenital disorders.


1. “Dextrocardia: an incidental finding” Yusuf SW, Durand JB, Lenihan DJ, Swafford J. Tex Heart Inst J 2009;36(4):358-9.
2. Garg N, Agarwal BL, Modi N, Radhakrishnan S, Sinha N. Dextrocardia: an analysis of cardiac structures in 125 patients. Int J Cardiol 2003;88(2–3):143–56
3. Bernasconi A, Azancot A, Simpson JM, Jones A, Sharland GK. Fetal dextrocardia: diagnosis and outcome in two tertiary centres. Heart 2005;91(12):1590–4.


Normal electrocardiogram - sinus rhythm
Sinus rhythm electrocardiogram

A contraction, from the Greek [συστολή] (systolí) meaning “contraction”, also [συστελλει] (systellei) meaning “to shrink, to shorten, or to draw together”.

It refers to the contraction of the heart. If you analyze a normal heartbeat (sinus rhythm), there are two systoles: an atrial systole, followed by a short interval, followed by the ventricular systole. The term systole is usually used in reference to the ventricular systole.

Systole was first recognized and named by Herophilus of Alexandria (325-255BC), most probably trough animal vivisection. Herophilus was accused of animal vivisection and the dissection of human cadavers. Because of this, some call Herophilus "The Father of Anatomy".

Galen of Pergamon (129AD - 200AD) used the term [συστελλεσθαι] meaning “contracted”.

The word in English was first used in the 16th century and was originally written as “sistole”, with an "i" instead of the accepted use today with a "y". The modern pronunciation in English follows the Greek pronunciation by ending the word in a long “e” as in “to be”.

1. "The Origin of Medical Terms" Skinner, HA 1970 Hafner Publishing Co.
2. "Medical Meanings - A Glossary of Word Origins" Haubrich, WD. ACP Philadelphia
3. "Dorlands's Illustrated Medical Dictionary" 26th Ed. W.B. Saunders 1994
4. "Greek anatomist Herophilus: the father of anatomy" Si-Yang, N. Anat Cell Biol. 2010; 43(4): 280–283

Note: Google Translate includes the symbol (?). Clicking on it will allow you to hear the pronunciation of the word.