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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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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 or sensory aphasia (or dysphasia). Broca's and Wernicke's areas are connected by an intrahemispheric tract known as the arcuate fasciculus (see image).
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
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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.
Image modified from the original: "3D Human Anatomy: Regional Edition DVD-ROM." Courtesy of Primal Pictures
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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
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External view of the occipital bone
The term [inion] is Greek [ινιον] and originally referred to the posterior aspect of the neck or occiput and its musculature and strength, as mentioned in the Iliad.
The term fell in disuse for hundreds of years, until it was resurrected by Peter Paul Broca (1824-1880) as a craniometric point. The inion is the midline protuberance in the posteroinferior aspect of the external surface of the occipital bone. Today, in most anatomy texts the inion is referred to as the "external occipital protuberance"
The inion is found at the intersection of three bony lines that are easily palpable, the bilaterally situated superior nuchal line, and the median nuchal line. It is labeled "Ext. occip. protuberance" (see accompanying image). There is a corresponding internal occipital protuberance in the internal aspect of the occipital bone.
Sources:
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 "Tratado de Anatomia Humana" Testut et Latarjet 8 Ed. 1931 Salvat Editores, Spain
4. "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 bartleby.com
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The word [sesamoid] means "similar to a sesame". First used by Galen c.180AD, he describes small ovoid bones that are "similar to a sesame seed", referencing the seed of the plant sesamum indicum, the oil of which was used as a laxative at that time.
Sesamoid bones are found in the tendons of some muscles and are mostly inconstant. Largey and Bonnet proposed a classification for these bones as: accessory, capsuloligamentous, intratendineous, and mixed.
Of special interest to this article are the sesamoid bones found within the two tendons of the flexor hallucis brevis muscle in the base of the foot (see accompanying X-ray image). These bones, especially the medial sesamoid bone, was attributed religious, mystical, and magical powers since ancient times. This is due to the fact that this small bone is highly resistant to natural decomposition. A Hebrew medical text dated 210 BC, attributed to Ushaia presented a small bone he called "luz" as the "depository of the soul". Many other authors, including Vesalius (who called it Albadaran), believed that upon resurrection, the whole body could reform from this "seed" bone.
This belief was later reinforced by religious texts into the early Renaissance which stated that this bone was indestructible and its presence was enough to guarantee resurrection for believers.
Note: The original X-ray was published here courtesy of Wesley Norman, PhD in his website. The website is no longer available, so the image is now in the public domain via www.archive.org.
Sources:
1. "Les os sesamoides de l’hallux : du mythe a`la fonction" Largely,A; Bonnel, BE Med Chir Pied 2008 24: 28–38
2. "Tratado de Anatomia Humana" Testut et Latarjet 8 Ed. 1931 Salvat Editores, Spain
3. "De Humani Corporis Fabrica" Vesalius, Andrea. 1543 Oporinus
Thanks to the first year medical students at the University of Cincinnati who inspired this article. Dr. Miranda
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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.
Ignaz Semmelweis
Ignaz Semmelweis, MD (1818- 1865). Born in Budapest as Ign?c F?l?p Semmelweis, he started his university studies as a lawyer, but changed to Medicine and in 1844, at the age of 26, attained his MD degree. in 1847 he was appointed as an assistant in Obstetrics, almost at the same time of the death of a friend (Kolletschka, a pathologist) who died of what appeared to be "puerperal fever", also known as "childbed fever" after being accidentally stabbed by a knife during the autopsy of a female who had died of that disease. Semmelweis reasoned that the disease somehow was transmitted via the wound and started a crusade to have surgeons and students clean their hands with a carbolized solution before examining a healthy pregnant woman.
Although the obstetric wards under his care reduced the rate of this disease to almost nothing, Semmelweis endured criticism from his teachers, colleagues, and peers, and he did not make any friends by calling "murderers" those who did not follow his ideas. murderers". An excerpt of a letter to one of this detractors reads: "I denounce you before God and the world as a murderer and the history of puerperal fever will not do you an injustice when for the service of having been the first to oppose my life-saving technique it perpetuates your name as a medical Nero". He did not publish his findings until later in life, and then received even more criticism.
In 1865 was committed to an mental asylum only to die a few days later. He was only 47 years old. The same year he died Joseph Lister performed the first operations using antiseptic technique.
Sources:
1. Newsom S." Pioneers in Infection Control - Semmelweis, Ignaz Philipp". The Journal of hospital infection. 1993-03-01;23:175-187.
2. Ellis, H. (2008). Ignaz Semmelweis: tragic pioneer in the prevention of puerperal sepsis. British Journal Of Hospital Medicine (London, England: 2005), 69(6), 358
3. " A Corner of History: Ignaz Philipp Semmelweis" Wynder, EL Prev Med 3" (4) Dec 1974, 574-580
4. "Ignaz Semmelweis; a hand-washing pioneer" P. Rangapa JAPI May 2010 58:328
Original image courtesy of Images from the History of Medicine