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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A [hordeolum] is an inflamed Meibomian gland (also known as a tarsal gland). These glands are found at the edge of the eyelids and their lipid product (meibum) helps seal the eyes and prevent tear evaporation. The vernacular term for an hordeolum is "stye" or "sty".

The term arises from the Latin [hordeum] meaning "barley". It refers to the appearance of the inflamed gland to a barleycorn. The eponymic term "Meibomiam gland" honors Heinrich Meibom (1638-1700), a German anatomist who first described the tarsal glands of the eye.

The removal of a hordeolum is called a "hordeolectomy"

Image courtesy of Wikipedia

HordeolumFive-day old hordeolum

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From the Greek [spondylos] meaning "vertebra", its combining form is [spondylo-]. Use of this term include:

SpondylitisInflammation of a vertebra.
- Spondylosis: The suffix [-osis] means "condition", but with the connotation of "many". The term means "many vertebrae", but it refers to excessive abnormal growth of portions of the vertebral body, usually forming "bone spurs", also referred to as "spondylophytes"
- Spondylolysis: From the Greek [lysis], meaning "loosening", the term is used to mean "destruction" or "breaking of". Spondylolysis refers to the breakage, destruction, or loosening of part of a vertebra.
- Spondylolisthesis: From the Greek term [olisthos] meaning "slippery".  A "slippery vertebra", referring to the forward displacement of a vertebra over another one.

Image property of: CAA.Inc. Photographer: David M. Klein

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Peter Paul Broca

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.
Peter Paul Broca (1824- 1880). Surgeon and anthropologist, Peter Paul Broca was born in Sainte-Foy-la-Grande in France. His earlier studies were in mathematics, but graduated in medicine, becoming a professor of clinical surgery. He became interested in anthropology and applied his mathematical expertise to the measurement and interpretation of his findings in comparative anatomy.

Broca was the founder of the first Anthropological Society of Paris, and used this venue to deliver most of his work. A prolific writer, Broca published over 500 scientific papers and several books. At one of the meetings of the society the discussion was directed to brain areas and speech. Broca had a patient with a condition that he referred to as aphemia (later known as aphasia); this patient died a few days later and upon autopsy, Broca was able to see a distinct cavity in the left lateral frontal lobe. Upon finding the same situation in another patient, he was able to describe the area of the brain responsible for speech, known today as "Broca's area" in the third left frontal brain convolution. Broca is responsible for naming many of the craniometric points in the human skull such as bregma, dacryon, inion, lambda, metopion, etc.

Broca was part of the discovery and study of the Neanderthal man. He remained the secretary of the Anthropological Society of Paris until his death in 1880. 

Peter Paul BrocaOriginal imagecourtesy of
National Institutes of Health.
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The term [aphasia] has Greek origins and means "without speech". This pathology was first described by Paul Broca who called it "aphemia".

Aphasia is a total and complete loss of speech. Lesser presentations of this condition should be called [dysphasias) from the prefix [dys-] meaning "abnormal", and  [phasia], meaning "speech".

Aphasia is the lack of spoken  speech due to cerebral cortex damage in the dominant brain hemisphere, usually the left side in right-handed individuals. There are two main areas of the brain involved in speech: Broca's and Wernicke's. Broca's area is responsible for speech expression (the spoken and written word). Damage to this area causes expressive or motor aphasia (or dysphasia).

Wernicke's area is responsible for the comprehension of speech, the understanding of language. Damage to this area causes receptive orsensory aphasia (or dysphasia). Broca's and Wernicke's areas are connected by an intrahemispheric tract known as the arcuate fasciculus (see image).

Broca and Wernicke's areas in the dominant brain hemisphere

Broca and Wernicke's areas in the dominant brain hemisphere

Complete loss of all communication abilities is called global aphasia. Other dysphasia pathologies are:

• Agraphia / dysgraphia: Incapacity / difficulty in writing
• Anomia / dysnomia: Incapacity / difficulty in naming objects
• Aphrasia / dysphrasia: Incapacity / difficulty forming phrases or sentences. The patient can communicate with single words, but cannot form sentences.

Image under copyleft agreement courtesy of The Brain from Top to Bottom
Thanks to  Margaret P. Tschimperle for suggesting this word. 

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The scaphoid is one of the proximal carpal bones that form the wrist. The name arises from the Greek [scaphe], meaning "boat"; and [-oid], meaning "similar to". The scaphoid bone roughly resembles a rowboat. It is also known as the navicular bone (from the Latin [navis] meaning "boat"), and os naviculare manus.

Proximally, the scaphoid bone articulates with the radius. Distally, the scaphoid articulates with the trapezium and trapezoid bones. On its medial  aspect, the scaphoid bone has two articular surfaces for the lunate and the hamate bones. The scaphoid bone also has very strong ligamentous connections with the lunate bone by way of the scapholunate interosseous ligament

The accompanying image shows the anterior (volar) surface of the wrist. Click on the image for a larger picture.

Image modified from the original: "3D Human Anatomy: Regional Edition DVD-ROM." Courtesy of Primal Pictures

Scaphoid bone - anterior (volar) view of the wrist


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Medial / lateral

The terms [medial] and [lateral] are opposing anatomical relationship terms that indicate the location of a structure or structures in relation to the midline or median plane. The accompanying image depicts the median plane.

The term "midline" is a bit of a misnomer, as this is a plane and not a line, although if you look at the median plane from the anterior or posterior aspect of an individual in the anatomical position, you would have a line, ergo, midline! Look at this article on the anatomical position to see an explanation and image of this concept.

The term [medial] means "closer to the midline". An example of the use of this term is: "the head of the clavicle is medial to the shoulder joint", that is, the head of the clavicle is closer to the midline than the shoulder joint.

The term [lateral] means "further from the midline". An example of the use of this term is: "the wrist joint is lateral to the elbow joint", that is, the wrist joint is further away from the midline than the elbow joint.

Click on the image for a visual explanation of the concepts of "medial" and "lateral".


Images property of: CAA.Inc. Artist: Victoria G. Ratcliffe

Medial / Lateral
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