Medical Terminology Daily - Est. 2012

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 George Bachman

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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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.

Jan Evangelista Purkinje
Jan Evangelista Purkinje

Jan Evangelista Purkinje (1787 - 1869). Known by his German name Purkinje, or his Czech name, Purkyn?, as well as his church-given name Salverius. Purkinje was born in the city of Libochovice, Bohemia, (now Czechoslovakia). He started his early studies in the church with Piarist monks. He took the name of Brother Salverius and served as a teacher in the Piarist schools. He dedicated himself to the study of natural sciences. Purkinje left the monastery before taking his final vows.   Purkinje continued his studies and graduated in medicine in Prague. Even as a student Purkinje started research on the physics of sound and the physiology of vision, which he continued after his graduation. Purkinje was one of the first to understand the vision of motion, thus creating the first animated cartoons!

In 1823 Purkinje was appointed Professor of Physiology at the University of Wroclaw (Breslau), later taking the same chair in Prague. Besides being one of the first to propose experimental physiology as basis for research, Purkinje was one of the first to use the microscope to study the cells of the body, proposing the "cell theory", and introducing the word "protoplasm".

He made a number of discoveries, and his name is eponymically tied to many structures and processes, such as:

  • Purkinje's cell of the cerebellum: Piriform cells found in Purkinje's layer
  • Purkinje's fibers of the heart: These are not "fibers" as the name implies, but fast-conducting myocardial cells found as the most distal components of the conduction system of the heart
  • Purkinje's law of vertigo: An observation that the apparent motion perceived when stopping the head after rotation changes from horizontal to vertical if the head is inclined laterally. This is important to pilots, as they are trained to understand that in conditions without external reference, moving the head down or laterally can induce uncontrollable vertigo.

Sources:
1. "Purkinje JE (1845) Mikroskopisch-neurologische Beobachturgen" Arch Anat Physiol Wiss Med II/III:281-295

2. "Jan Evangelista Purkinje (1787-1869)" J Neurol Neurosurg Psychiatry. 1994 July; 57(7): 777 
3. "Jan Evangelista Purkinje (1787-1869)" Davies, MK; Hollman A. Heart (1996) 76(4): 311