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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 [dysphoria] is composed of the prefix [dys-] meaning "abnormal, the root term [-phor-] meaning "to bear" or "to carry", and the suffix [-ia] meaning "condition" or "situation". The root term requires a little more explanation. Initially the term was used to denote "enduring", later "productive" or "fertile" and in modern medical terminology, the meaning of mental health, as in to "carry oneself" or "well-being".
Thus explained, dysphoria means "a condition of abnormal feeling about oneself". The term is used in depressive mood disorders and is characterized by anxiety, depression, sleeping disorder, etc.
The opposite of dysphoria is [euphoria] from the Greek suffix [eu-] meaning "good" or "well". Euphoria is "feeling good"
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Wormian bones are small flat bones found within the suture joints of the cranium. They are also known as "intrasutural bones" (see image). These bones will vary in number and in size per individual, and are not rare to find.
These bones are eponymic, named after Olao Claus Worm Sr. (1588 - 1654), a Danish professor of Medicine and Physiology. Known by his Latinized name Olaus Wormius, he described the embryology of these bones. The eponym was created by his nephew Thomas Bartholin (1616 - 1680).
An interesting variation of a Wormian bone is the [Inca bone] also known as the Os Incae. This is an interparietal bone which can present many variations, its importance being that it can be misdiagnosed as a skull fracture, specially in children.
Sources:
1. "Interparietal bone: a case report"Mirsa, BD. J Anat Soc India (1960) 9; 39.
2. "Variations of the interparietal bone in man" Pal,GP J Anat (1987)152; 205-208.
3. "Radiological case of the month" Parente, K et al Arch Ped Adolesc Med (2001) 155;731-732
4. "The Origin of Medical Terms" Skinner, HA 1970 Hafner Publishing Co.
Article image in public domain, modified from Toldt's "Atlas of Human Anatomy", 1903
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Today, instead of writing an article for this blog I prepared and delivered a lecture on "Surgical Sutures, Needles, and Knots" which included a short hands-on lab on knots and wound closure on simulated tissue.
This was presented at the request of the Pre-Health club of the College of Mount Saint Joseph in Cincinnati, OH. I am always glad to be invited to do these presentations as they allow me to maintain contact with the future generation of Health Care Professionals.
Of course this is a very short presentation compared to the longer course that Clinical Anatomy Associates, Inc. delivers for medical companies, but it shows these future professionals the complexity of the world of wound closure, healing, surgical sutures, needles, and knots.
We ended the lab with the challenge to do a two-layer closure of a simulated wound. Most of the attendees did a pretty good job. Congratulations!
My personal thanks to Dr. Eric Johnson who coordinated the meeting, and to the Pre-Health Club for their invitation. For more pictures of the meeting, see the Facebook album page of "Medical Terminology Daily"
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The root term [-rachi-] comes from the Greek word [?άχις] (rhakhis) and means "a spine" or "a ridge". It is used to denote the spinal or vertebral column. This root term is used in many sciences such as botany, zoology, comparative anatomy, etc. Some of these uses can be read here.
The plural for is rachides. Examples of its use in human anatomy and pathology are:
• Rachitic: An individual with spine pathology. A patient with cachexia so severe that the spine is clearly seen
• Rachischisis: A congenital separation or cleft usually found in the lower portion of the spinal colum
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The suffix [-schisis-] comes from the Greek word [σχίσις] and means "to tear" or "to separate". In Medicine today its meaning is that of "a cleft", a "split", or "a separation".
Examples of its use are:
- Palatoschisis: A cleft or separation of the palate, also known as uranoschisis
- Cheilognathopalatoschisis: This word combines several roots: [-cheil-], meaning "lip", [-gnath-] meaning "jaw", [-palat-], meaning "palate", while the suffix [-schisis] means "to split". A split or separation of the lip, jaw, and the hard and soft palate.
- Cranioschisis: A congenital cleft in the cranium
- Rachischisis: A congenital separation or cleft usually found in the lower portion of the spinal column
- Gastroschisis: A congenital condition where the abdominal wall does not complete its normal closure and the baby is born with an incomplete abdominal wall allowing for the extrusion of abdominal viscera usually in a right paraumbilical position
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The pelvic brim is an oval-shaped bony ridge in the pelvis formed by components of the sacrum, ilium, pubic bone, and symphysis pubis.
Also known as the "linea terminalis" the pelvic brim is formed from posterior to anterior by:
• Sacral promontory: An anterior ledge formed by a protrusion caused by the anular epiphysis of the first sacral vertebra
• Arcuate line: A medial border in the iliac bone. The anterior edge of the arcuate line where it continues with the pectineal line of the pubis is not clear
• Pectineal line of the pubis: A sharp posteromedial bony ledge in the superior aspect of the superior pubic ramus
• Pubic tubercle: A small bony protrusion in the superior aspect of the pubic bone
• Pubic crest: The superior aspect of the body (corpus) of the pubic bone, site of attachment for the rectus abdominis and pyramidalis muscles
• Pubic symphysis: The superior aspect of the pubic symphysis and related ligaments
The pelvic brim serves as an anatomical landmark that separates the abdminopelvic cavity into its two components: Superior to the pelvic brim is the abdominal cavity and inferior to it is the pelvic cavity. The gender differences in the shape of the pelvic brim as well as its measurements and dimensions will be covered in a separate article.
Images modified from the original courtesy of Wikipedia



