Surface anatomy

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A Moment in History

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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Details: Written by: Efrain A. Miranda, Ph.D.; Published: August 21, 2018; Hits: 20104

Surface anatomy art by Danny Quirk - with permission

UPDATED: Surface anatomy is a subset of human anatomy that studies the relationship of external anatomical landmarks and deeply situated structures. These landmarks are created by cartilage, bones, tendons and muscles. In some cases they may be caused by a hypertrophic or diseased organ. Palpation is and art and my favorite book on the subject is the "Trail Guide to the Body" series by Andrew Biel

Surface anatomy is a core clinical skill for physicians, physical therapists and other health care professionals (HCP), as palpation in specific locations can lead to rapid diagnosis in certain cases. It is also used in surgery to determine the appropriate place for incisions or insertion of a trocar in the case of minimally invasive surgery.

It is true that individual habitus and anatomical variations must make the HCP wary of potential mistakes, but in the majority of cases these anatomical landmarks and diagnoses are correct.

Many book chapters have been written on the topic, but unfortunately, the need to dedicate time to modern discoveries have reduced the time spent on this wonderful learning tool to the point that modern books of anatomy barely touch upon the subject. Many feel today that the need for this tool has been made irrelevant by the bed-side availability of ultrasound imaging. I have to agree with Standring (2012) when she states “I am not convinced that surface anatomy is under growing threat from modern imaging technology…” There is and always will be the need for applied surface anatomy, although maybe not in the way and depth it was used in the past when imaging technology was scarce and expensive.

In order to make the importance of surface anatomy relevant in medical schools, some have added body painting as a tool in their anatomical curriculum with great results. Will it be used everywhere? I doubt it, but here again is a link between human anatomy and art, which our contributor Pascale Pollier presents through her art in "Artem Medicalis".

The artwork in this article is by Danny Quirk. Click on the image for a larger depiction. The video links are for the RMIT University Muscle Man and the Skeletal Man body paintings from the class by Dr. Claudia Diaz.

Personal note: One of the best book chapters on Surface Anatomy was written in "The Anatomical Basis of Clinical Practice" by Becker, Wilson and Gehweiler (1971). Unfortunately, although the content is very good, the images used, the tongue-in-cheek humor, and writing style used by the authors, plus the times at which the book was published forced the publisher stop the sales of this book. It was banned from use in medical colleges through the country. Known to many as the "green book" because of its cover, it is today considered a collector's curiosity. In the "sources" section of this article you can find a links to a journal article on the subject as well as images of the book. Dr. Miranda.

Sources:
1. “Evidence-Based Surface Anatomy” Standrig, S J Clin Anat (2012) 25:813–815
2. “Giving Color to a New Curriculum: Body paint as a Tool in Medical Education” Den Akker, JW. Et al J Clin Anat (2002) 15:356–362
3. “Body-Painting: A Tool Which Can Be Used to Teach Surface Anatomy” Nanjundaiah, K. J Clin Diag Res (2012) October, Vol-6(8): 1405-1408 Copy of the article here
4. “RMIT students paint anatomical man into human textbook” RMIT Dr. Diaz, C. Copy of the article here
5. “Should We Use Body Painting to Teach Anatomy?” Gambino, M article at Smithsonian.com
6. “The role of Fresh Tissue Dissection and Anatomic Body Painting in Anatomy Education” Bennet, C. PPT presentation on PDF here
7. " The anatomical Basis of Medical Practice" Becker, RF. Wilson, JW, Gehweiler, JA 1971, Baltimore, Williams & Wilkins
8. "The Pornographic Anatomy Book? The Curious Tale of The Anatomical Basis of Medical Practice" Halperin EC, Acad Med (2009) 84:2; 278-283 Article here
9. "The Objectification of Female Surface Anatomy" Ruiz, V. Internet article. Click here

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