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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 root term [-lamin-] is a derivate from the Latin word [lamina] which means "something thin", such as a thin plate or a fish scale. Its plural form is [laminae].
The term lamina is used in human anatomy to describe thin structures, like the lamina spiralis of the inner ear, and the bilateral laminae of the vertebrae.
The root term [-lamin-] is used in words such as:
- Laminotomy: The suffix [-otomy] means "to open". Opening of a lamina
- Laminectomy: The suffix [-ectomy] means "to remove". Removal of a lamina
- Lamination: To make or form into a thin structure, a lamina
- Laminaria: A genus of algae characterized by thin leaves
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The word [lamella] is Latin and is the diminutive form of [lamina], which means "thin", or a "small plate". A lamella is a thin, wafer-like structure. The plural form is [lamellae]. The adjectival form [lamellar] refers to structures that resemble a stack of thin plates.
Many structures in the human body have a lamellar organization, such as compact bone, the pubic symphysis, and intervertebral discs. The accompanying image is a superior view of an intervertebral disc. Click on the image to see a larger depiction and the lamellar structure of the anulus fibrosus, the external component of the disc.
Image modified from the original from Testut and Latarjet, 1931
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The pubic symphysis is a joint found between the pubic bones. It is composed by a layer of hyaline cartilage that covers the medial surface of each pubic bone (os pubis), and a fibrocartilaginous disc arranged in lamellae, somewhat akin to the structure of an intervertebral disc. It is classified as a fibrocartilaginous joint or a secondary cartilaginous joint. It generally presents with an internal midline cleft and is surrounded by strong ligaments. This joint has very little movement, limited to about one degree. The ligaments are:
• Superior pubic ligament: Found on the public crest, this ligament extends laterally as far as the pubic tubercles. It also serves as anchoring point for the tendons of the rectus abdominis muscles and the pyramidalis muscle.
• Inferior pubic ligament: Also known as the subpubic ligament this ligament forms an arch and attaches to the inferomedial aspect of the inferior pubic rami
• Anterior pubic ligament: Found anterior to the pubic symphysis, this ligament attaches to the periosteum of the anterior aspect of the body of the pubic bone
•Posterior pubic ligament: Found on the posterior aspect of the pubic bone, this ligament is the anterior boundary of the retropubic space of Retzius
Under the influence of hormones, the pubic symphysis becomes softer and more mobile in pregnant women. This is good for natural birth, but can be the cause of symphyseal pain in the later stages of pregnancy.
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This medical word is formed by the prefix [-dys-] meaning “abnormal”, the root term [-kin-] meaning “movement”, and the suffix [-esia] meaning “condition” or “situation". Dyskinesia is “a condition of abnormal movement”.
Dyskinesia refers to a wide variety of involuntary movements that are either extraneous, or a fragmentation of normal movements of the face or limbs. The etiology for dyskinesia can be pharmacological, because of long-term use of antipsychotic medicine (tardive dyskinesia) or related to damage (trauma) or abnormal development of deep brain structures.
Dyskinetic movements are involuntary and classified as:
- Tremor: Small oscillating movements either at rest or during muscle activity, as in Parkinson’s disease
- Chorea: Irregular random and excessive movements
- Myoclonus: Rapid, fast and arrhythmic movements
- Tics: Brief and repetitive movements
- Dystonia: Postures that are involuntary and maintained for a brief time
Following are links to YouTube videos that show patients with different types of dyskinesia. These videos will open in a separate page
WARNING! These videos could be disturbing to some viewers. Videos courtesy of the JAMA Network.
Video 1: Demonstration of Kinesigenic Dyskinesia
Video 2: Choreathetotic Movement Attack in a Patient With Paroxysmal Nonkinesigenic Dyskinesia
Video 3: Orofacial Dyskinesia
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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.
Adrian Van Der Spigelius
Adriaan Van Der Spigelius (1578 - 1625). Sometimes knows as Adrianus Spigelius, was a Flemish surgeon, anatomist, and botanist born in Brussels. Just as Vesalius, he studied at the University of Louvain, and later in Padua, Italy. Having settled as a professor of anatomy in Venice, in 1616 he was offered and accepted the Chair of Anatomy at Padua. His posthumous work "De Humani Corporis Fabrica Libri X" was published in 1627.
Spigelius described the caudate lobe of the liver and the "linea semilunaris", the lateral border of the rectus abdominis muscle. Today, a ventral hernia that occurs in the linea semilunaris is said to be an "Spigelian hernia".
His name is also associated with the Spigelian fascia, formed by the combined aponeuroses of the external oblique muscle, the internal oblique muscle and the transversus abdominis muscle.
If you hover over Spigelius' image, you will see an anatomical drawing depicting the linea semilunaris (arrow).
Original image courtesy of Wikipedia. Hover image property of:CAA.Inc.. Artist:D.M. Klein
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The root term [-kin-] and its variation [-kine-] originate from the Greek word [κινέω] (kineo) and means "to move", or "place in motion". Applications of this root term include:
- Kinesiology: Study of movement
- Dyskinesia: Abnormal movement
- Kinetic: Pertaining to movement
- Kinesis: Movement
- Cytokinesis: Cell movement
- Kinesthesia: Sensation of movement, etc.
The root terms [-cine-] and [-cinemat-] are a variation of [-kine-] and also mean "movement". They are the basis of the word "cinematography" which means "process of writing or recording movement" in other words "moving pictures". The shortened version gives us [cinema]. Medical use of these root terms gives us:
- Cineangiography: Recording of vessels in movement
- Cineangiocardiography: Recording of the heart vessels in movement
- Coronary cineangiography: Pertaining to movement of the coronary vessels