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Jean George Bachmann
(1877 – 1959)
French physician–physiologist whose experimental work in the early twentieth century provided the first clear functional description of a preferential interatrial conduction pathway. This structure, eponymically named “Bachmann’s bundle”, plays a central role in normal atrial activation and in the pathophysiology of interatrial block and atrial arrhythmias.
As a young man, Bachmann served as a merchant sailor, crossing the Atlantic multiple times. He emigrated to the United States in 1902 and earned his medical degree at the top of his class from Jefferson Medical College in Philadelphia in 1907. He stayed at this Medical College as a demonstrator and physiologist. In 1910, he joined Emory University in Atlanta. Between 1917 -1918 he served as a medical officer in the US Army. He retired from Emory in 1947 and continued his private medical practice until his death in 1959.
On the personal side, Bachmann was a man of many talents: a polyglot, he was fluent in German, French, Spanish and English. He was a chef in his own right and occasionally worked as a chef in international hotels. In fact, he paid his tuition at Jefferson Medical College, working both as a chef and as a language tutor.
The intrinsic cardiac conduction system was a major focus of cardiovascular research in the late nineteenth and early twentieth centuries. The atrioventricular (AV) node was discovered and described by Sunao Tawara and Karl Albert Aschoff in 1906, and the sinoatrial node by Arthur Keith and Martin Flack in 1907.
While the connections that distribute the electrical impulse from the AV node to the ventricles were known through the works of Wilhelm His Jr, in 1893 and Jan Evangelista Purkinje in 1839, the mechanism by which electrical impulses spread between the atria remained uncertain.
In 1916 Bachmann published a paper titled “The Inter-Auricular Time Interval” in the American Journal of Physiology. Bachmann measured activation times between the right and left atria and demonstrated that interruption of a distinct anterior interatrial muscular band resulted in delayed left atrial activation. He concluded that this band constituted the principal route for rapid interatrial conduction.
Subsequent anatomical and electrophysiological studies confirmed the importance of the structure described by Bachmann, which came to bear his name. Bachmann’s bundle is now recognized as a key determinant of atrial activation patterns, and its dysfunction is associated with interatrial block, atrial fibrillation, and abnormal P-wave morphology. His work remains foundational in both basic cardiac anatomy and clinical electrophysiology.
Sources and references
1. Bachmann G. “The inter-auricular time interval”. Am J Physiol. 1916;41:309–320.
2. Hurst JW. “Profiles in Cardiology: Jean George Bachmann (1877–1959)”. Clin Cardiol. 1987;10:185–187.
3. Lemery R, Guiraudon G, Veinot JP. “Anatomic description of Bachmann’s bundle and its relation to the atrial septum”. Am J Cardiol. 2003;91:148–152.
4. "Remembering the canonical discoverers of the core components of the mammalian cardiac conduction system: Keith and Flack, Aschoff and Tawara, His, and Purkinje" Icilio Cavero and Henry Holzgrefe Advances in Physiology Education 2022 46:4, 549-579.
5. Knol WG, de Vos CB, Crijns HJGM, et al. “The Bachmann bundle and interatrial conduction” Heart Rhythm. 2019;16:127–133.
6. “Iatrogenic biatrial flutter. The role of the Bachmann’s bundle” Constán E.; García F., Linde, A.. Complejo Hospitalario de Jaén, Jaén. Spain
7. Keith A, Flack M. The form and nature of the muscular connections between the primary divisions of the vertebrate heart. J Anat Physiol 41: 172–189, 1907.
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Fusiform gyrus.
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.
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 in the public domain, courtesy of Wikimedia. org.
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
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(UPDATED)
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 pronounced "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... In fact, here is an article on "11+ medical words that are used incorrectly"
The image in this article is one of the few photographs that exists of Henry Gray. In this particular 1870 picture by Joseph Langhorn, Gray is in the anatomy laboratory (forefront, third from the left) at St. George’s Hospital with his students. At the time it was customary for medical students to pose in the anatomy lab with bones and cadavers. This is a practice not in use today which disappeared circa 1930. For anyone interested in this now considered gruesome custom, I would recommend the book "Dissection" by John H. Warner and James M. Edmonson.
Sources
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
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Complete keratinization of the ocular surface
in a patient with ocular cicatricial 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.
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)
Sources:
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
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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
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The infraspinatus muscle is a thick, triangular muscle and one of the four muscles that forms the rotator cuff. It is found in the posterior aspect of the scapula, in its infraspinous fossa, inferior to the scapular spine. The muscle is covered on its posterior aspect by a thick fascia, the infraspinatus fascia. This fascia separates the infraspinatus muscle from the teres minor and teres major muscles.
The muscle originates from the infraspinous fossa and from the deep aspect of the infraspinatus fascia. The muscular fibers converge superolaterally for form a tendon that inserts into the the greater tubercle of the head of the humerus. The tendon hugs the glenohumeral joint capsule and is separated from it by a small bursa. Some of the tendon fibers insert into the joint capsule.
The infraspinatus is the main external rotator of the shoulder. When the arm is fixed, it adducts the inferior angle of the scapula.
It receives innervation by way of the suprascapular nerve (C5, C6), which arises from the superior trunk of the brachial plexus.
As part of the shoulder’s rotator cuff it helps prevent subluxation of the glenohumeral joint by keeping the head of the humerus in situ. The infraspinatus is one of the 17 muscles that attach to the scapula.
Note: The side image is modified from the original by Henry VanDyke Carter, MD. Public domain. Animated image below by Wikimedia Commons - Anatomography [CC BY-SA 2.1 jp (https://creativecommons.org/licenses/by-sa/2.1/jp/deed.en)]
![Infraspinatus muscle Anatomography [CC BY-SA 2.1 jp (https://creativecommons.org/licenses/by-sa/2.1/jp/deed.en)]](https://upload.wikimedia.org/wikipedia/commons/8/8d/Infraspinatus_muscle_animation.gif)
Sources:
1. “Gray’s Anatomy” Henry Gray, 1918
2. "Tratado de Anatomia Humana" Testut et Latarjet 8th Ed. 1931 Salvat Editores, Spain
3. "Gray's Anatomy" 38th British Ed. Churchill Livingstone 1995
4. “An Illustrated Atlas of the Skeletal Muscles” Bowden, B. 4th Ed. Morton Publishing. 2015
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The levator scapulæ muscle (levator anguli scapulæ) is a triangular multipennate muscle which extends between the cervical spine and the scapula. This muscle is deep to the sternocleidomastoid and trapezius muscle.
It is formed by discrete muscular slips that originate from the first four transverse processes (C1-C4). It can have an extra slip from C5 (as shown in the side image).
These muscular slips pass posteroinferiorly, joining, and inserting in the superior scapular angle and the scapular medial border between the superior scapular angle and the medial origin of the scapular spine. It may attach to the scapular spine.
There are other anatomical variations including muscular slips that may extend to the occipital bone or mastoid process, to the trapezius, scalene, or serratus anterior magnus muscles, or to the first or second rib.
It receives nerve supply from the fourth and fifth cervical nerves and by a branch from the dorsal scapular nerve. The dorsal scapular nerve arises from the C5 root of the brachial plexus.
It receives its blood supply from the dorsal scapular artery.
The function of this muscle depends on which bony element is fixed, the scapula or the cervical spine. When the spine is fixed, the levator scapulae elevates the scapula and pulls the superior portion of the medial scapular border superomedially. When only one scapula is fixed, the head and neck flexes and rotates ipsilaterally while it extends the neck contralaterally.
The order and shape of the muscular slips is interesting, as the slip from the transverse process of the Atlas (C1) twists posteriorly and descends to insert as the most posterior and inferior fibers in the medial border of the scapula. The other slips follow a similar pattern, which is what allows this muscle to rotate the neck. This indicates that the fibers of the levator scapulae muscle are spiral and the fibers follow the contour of the neck. This makes (to my knowledge) the levator scapulae the only spiral muscle of the body. This is shown as "A" in the second side image; "B" represents the misconception on the direction of the fibers in this muscle.
Since it is a common sign of stress and bad posture to raise the shoulders, this muscle can spasm, causing neck pain and in some cases be a trigger for headaches.
The Levator scapulæ is one of the 17 muscles that attach to the scapula.
Note: The first side image shown in this article is from “Gray’s Anatomy” (1918) which is in the public domain. The second side image is from Arnold’s “Reconstructive Anatomy” (1968).
Note: Animated image below by Wikimedia Commons - Anatomography [CC BY-SA 2.1 jp (https://creativecommons.org/licenses/by-sa/2.1/jp/deed.en)]
![Anatomography [CC BY-SA 2.1 jp (https://creativecommons.org/licenses/by-sa/2.1/jp/deed.en)]](https://upload.wikimedia.org/wikipedia/commons/a/a1/Levator_scapulae_muscle_animation_small2.gif)
Sources:
1. “Gray’s Anatomy” Henry Gray, 1918 2. "Tratado de Anatomia Humana" Testut et Latarjet 8th Ed. 1931 Salvat Editores, Spain
2. "Tratado de Anatomía Humana" Testut et Latarjet 8th Ed. 1931 Salvat Editores, Spain
3. "Gray's Anatomy" 38th British Ed. Churchill Livingstone 1995
4. “An Illustrated Atlas of the Skeletal Muscles” Bowden, B. 4th Ed. Morton Publishing. 2015
5. “Reconstructive Anatomy, A Method for the Study of Human Structure” Arnold, M. W.B. Saunders. 1968“Gray’s Anatomy” Henry Gray, 1918





