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

Johann Gottfried Zinn

Johann Gottfried Zinn

Anatomist and botanist, Johann Gottfried Zinn was born on December 6, 1727 in the city of Ansbach, Germany. He started his medical studies in his native city, becoming later a student of Dr.  Albrecht von Hallers at the University of Göttingen, and received his MD in 1749.

He left for Berlin to continue his studies but came back shortly thereafter. He became a professor of anatomy at the University of Göttingen and in 1753 he also became the director of the botanical garden in the same city.

He is known for his anatomical treatise on the anatomy of the human eye: “Descriptio anatomica oculi humani iconibus illustrata”. Because of this, his name has become an eponym in the “Zonule of Zinn”, a ring of strands that forms a fibrous band connecting the ciliary body with the capsule of the lens of the eye. Zonule of Zinn is sometimes referred to as the suspensory ligaments of the lens, or the “ligament of Zinn”. His name is also attached to the anular ring tendon found in the posterior aspect of the eye, the "anular tendon of Zinn". This ring serves as attachment for all the extraocular muscles of the eye and the optic nerve passes through the center of the ring.

Carol Linné (Carolus Linneaus) named a genus of flowers in the family Asteraceae known vernacularly today as “Zinnia” in his honor. Hover your cursor over his portrait to see the flower.

The chapter on orbital anatomy of his anatomy book, taken from the second edition in 1780, has been translated and the first of three parts is published in an issue of “Strabismus”

His book "Catalogus Plantarum Horti Academici Et Agri" can be seen online here.

His life was short, dying at the early age of 32, but his name lives on in the name of a beautiful flower.

1. “Johann Gottfried Zinn" Simonz, HJ Strabismus – 2004, Vol. 12, No. 2, p. 125 
2. "Anatomical Description of the Human Eye" Zinn, JG Strabismus, 13:45–52, 2005 
Images: Public Domain by Wikipedia Commons. 1. Own work I_am Jin, and H. Wilhem Dietz

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Prosopagnosia is a neurological disorder characterized by the inability to recognize faces.  It is also known as face blindness or facial agnosia. There are different degrees of presentation of this pathology and some patients go through life without knowing that they have this problem characterizing it as just “a quirk” or that “they just are not good at remembering faces”.

Advanced forms of prosopagnosia cause some patients not to be able to recognize their own face or their own family members. Prosopagnosia is thought to be the result of abnormalities, damage, or functional impairment in the right fusiform gyrus, located in the inferior occipitotemporal region of the brain. The fusiform gyrus is related to the limbic system and seems to coordinate the systems that control facial perception and memory.  Prosopagnosia can result from stroke, traumatic brain injury, or certain neurodegenerative diseases

Prosopagnosia seems to also be congenital and run in certain families, pointing to a possible genetic disorder in the fusiform gyrus region.

Fusiform GyrusFusiform gyrus.

The etymology of the term prosopagnosia is complex. It starts with the Greek word “gnosia”, a derivate of [γνώση] (gnósi)  meaning “cognition”, “awareness”, or "knowledge". Adding the prefix “a-" leads to [agnosia] meaning lack or absence of cognition or awareness. The prefix "prosop-" derives from the Greek term [πρόσωπο] (prósopo) means f"ace". Therefore, prosopagnosia means “absence of facial awareness”.

There are famous people with prosopagnosia including Jane Goodall and Steve Wozniak.

Here is an interesting video from YouTube on the topic.


Image courtesy of https://commons.wikimedia.org/wiki/File:Fusiform_gyrus_animation.gif
Video courtesy of YouTube and Lucy Barnarf
Note: The links to Google Translate include an icon ()that will allow you to hear the pronunciation of the word.d

10 medical words that are used incorrectly

1. In the heart, heart valve, and ring valvuloplasty arena, everybody talks about the “anulus”, but most everybody misspells it! The word anulus originates from the Latin term “anulus” meaning “ring”. The proper way of writing it is ANULUS not ANNULUS, with a double "n"

2. The word “process” is English, therefore its plural form should be pronounce as “processes” not with a Latinized inflection as “processiiis”

3. The inflammation of a tendon is “tendonitis”, not “tendinitis”

4. When there is an excess amount of fluid in the pericardium that interferes with cardiac function, that is called a cardiac “tamponade”, not a “tamponaade” (with a French accent) and please don’t call it a “tapenade” (I have heard it), a dish consisting of puréed or finely chopped olives, capers, anchovies and olive oil!

5. The singular form for “criteria” is “criterium”. The following is wrong:  “only one criteria was used to make the decision”. The proper sentence should be "only one criterium was used to make the decision".

6. When using a scope to examine the fundus of the uterus, the procedure is a funduscopic procedure, not fundoscopic! It is more euphonic, I will agree, but not correct!

7. In spinal anatomy, the term “a facet joint” is most commonly used, but the term should be pronounced with the accent on the first syllable as in “fácet”! And just to be a bit more correct, the proper term for a so-called “facet joint” is “zygapophyseal joint”

8. In colon pathology a “diverticulum” is an outpouching of the colon wall. The plural form for “diverticulum” is diverticula.  The terms diverticulae of diverticuli are not correct

9. The terms centigrade and centimeter are derivate from the Latin word “centus”, meaning “one hundred” therefore the “French-like pronunciation of centimeter and centigrade with a French twist, with a nasal initial "a" although cool, is not correct!

10. An finally, my pet peeve: The words “anatomy” and “dissection” are actually synonymous.  Anatomy has a Greek origin. Ana means “apart” and “otomy” is the “process of cutting”: “to cut apart”  Dissection has a Latin origin and means exactly the same! In fact, for many years the term “to anatomize” was used instead of “to dissect”!

Where is the problem? In the pronunciation! “Dissection” should rhyme with “dissent”. For a complete article on this topic, click here.

1. “"The Doctor’s Dyslexicon: 101 pitfalls in medical language" John H. Dirckx The American Journal of Dermatopathology. 27(1):86-88, FEBRUARY 2005 DOI: 10.1097/01.dad.0000148282.96494.0f PMID: 15677983


UPDATED: The term [plexus] comes from the Latin term [plectere] meaning " to twine, or to braid". In anatomy, the term [plexus] refers to a group of structures that are intertwined or form a meshwork.  The plural form is [plexuses], although the Latin plural form [plexi] is also correct. Gabrielle Fallopius used the term to denote "a tangle of nerves"

There are many plexuses described in the human body. Most are formed by nerves, but there are many that are lymphatic or vascular. The best known are the plexuses of nerves formed by the ventral rami of the spinal nerves. These are the cervical plexus, the brachial plexus, the lumbar plexus, and the sacral plexus. The image depicts the brachial plexus. For a larger version, click on the image, and for further information on the cervical and brachial plexuses, click here

Images and links courtesy of:www.bartleby.com

Brachial plexus (www.bartleby.com)

One of my pet peeves...


Say the following words out loud: "DISSECT" and "DISSECTION", then read on...

This is very high up on my list of personal annoyances or pet peeves. It was first brought up to my attention by Aaron Ruhalter, MD in his lectures. I was elated to find an article by Dr John H. Dirckx that took on the topic of the pronunciation of these terms. Dr. Dirckx states that the word should be pronounced with a short "i" as in "dissent"

The words “anatomy” and “dissection” are actually synonymous.  Anatomy has a Greek origin. "Ana" means “apart” and “otomy” is the “process of cutting”: “to cut apart”.

Dissection has a Latin origin and means exactly the same! In fact, for many years the term “to anatomize” was used instead of “ to dissect”! Where is the problem? In the pronunciation! “Dissection” should rhyme with “dissent”, "kissed", and "missed"

An argument could be made that the wrong pronunciation (dai-ssect) is so prevalent that it should be accepted. I disagree, the wrong pronunciation of a word does not make it acceptable.

Further to this argument is a listing of words that include the term (-iss-) which you can read online here. I challenge the audience to find one instance, besides "dissect" and "dissection" where the term is pronounces "ais" instead of "iss".

Other pet peeves:

- Using the word "leg" to mean "lower extremity" as the leg is only a segment of the lower extremity: click here
- Using the term "ramus" instead of "ramus intermedius" for an anatomical variation of the cardiac vasculature: click here
- Using the term "thoratomy" instead of the proper term "thoracotomy": click here

... do not get me started on anatomical and terminological pet peeves...

1. "The Doctor's Dyslexicon: 101 Pitfalls in Medical Language" Dirckx, JH Am J Dermatopath 2005 Vol: 27(1):86. DOI: https://doi.org/10.1097/01.dad.0000148282.96494.0f
2. The Free Dictionary :https://www.thefreedictionary.com/words-containing-iss

Pemphigus / pemphigoid

The term pemphigus refers to a rare group of autoimmune intraepidermal diseases characterized by blistering, pustules, or vesicles on the skin and mucous membranes. The mode of action of the disease is still not clear, but a key component is acantholysis, the disruption of the normal mechanisms of intercellular adhesion, which leads to intraepidermal blister formation.

There are several types of presentations of this disease such as p. vulgaris, p. foliaceus, p. vegetans, etc. One catastrophic presentation of this disease is ocular cicatricial pemphigoid. The pemphigoid disease progresses creating a symblepharon (adhesive attachments between the conjunctiva covering the sclera and the mucosa covering the posterior aspect of the eyelids. Eventually the disease may extend over the cornea. The accompanying image depicts a case of complete keratinization of the ocular surface in a patient with ocular cicatricial pemphigoid.

Complete keratinization of the ocular surface in patient with ocular cicatricial pemphigoid
Complete keratinization of the ocular surface in patient with ocular cicatricial pemphigoid.
Click on the image for a larger depiction 
The root term pemphig- derives from the Greek [πεμφίγος] meaning a pustule or blister; the suffix -oid  is also Greek [ειδής] meaning “similar to” of “kind of”. Therefore the medical term pemphigoid means “similar to blisters”

There is discussion as to when was this word first used, but it looks as though it was first published in 1763 in the book “Pathologia Methodica Practica, seu de Cognoscendis Morbis” by the French physician and botanist Francois Boissier de la Croix de Sauvages (1706 – 1767)

1. “Revue D’Histoire Des Sciences” Louis Dulieu, 1969
2. "Etymology of Pemphigus" Holubar, K. J Am Acad Dermat 1989:21, 155-156
3. "Pemphigus" Korman, N. J Am Acad Dermat 1988: 18/6  1219-38
4. “Ocular Cicatricial Pemphigoid” Khan R,. McDermott M., Hwang, F. Am Acad Ophthalm Eye Wiki https://eyewiki.aao.org/Ocular_cicatricial_pemphigoid

Image courtesy of EyeWiki


The root term [-brachi-] comes from the Latin word [brachium] meaning "arm". Do not confuse with [-brachy-], which means "small" or "short".

It must be pointed out that there is an important discrepancy between the vernacular use of the term "arm" (as the whole upper extremity) and the anatomical "arm". In human anatomy the "arm" is only the portion of the upper extremity found between the shoulder joint superiorly and the elbow joint inferiorly. In some radiology studies, the arm is referred to as the "upper arm" so as not to include the forearm. This use of the term "upper arm" is incorrect and should be avoided by medical professionals.

Examples of the use of this root term in human anatomy and pathology are:

• Brachialis: A flexor muscle in the upper extremity

• Brachial plexus: A plexus of nerves related to the upper extremity

• Brachioradialis: A flexor muscle that extends from the arm to the forearm