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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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A [cyst] is a small sac-like structure, usually characterized by a distinct membrane that separates the content from its surroundings. It usually contains serous fluid, but it can also contain semisolid materials. If the cyst contains pus, then it will be called an "abscess".
There are many types of cysts. One of them, shown in the accompanying image is a "ganglion cyst", a serous accumulation of fluids that is usually found near a joint or a tendon in the hands or feet. You can also read the article on "Nabothian cysts".
The image shows a ganglion cyst in the anterior aspect of the wrist.
The same word can be used as a root term, [-cyst-] arises from the Greek word [κύστη], pronounced(kisti), meaning "bladder". It is used in many words such as:
- Cholecystectomy: Removal of the gallbladder
- Cystic duct: The evacuation duct of the gallbladder
- Dacryocystolithiasis: Presence of stones in the lacrimal sac
- Cystoscope: An instrument to view into the urinary bladder
- Cystitis: Inflammation or infection of the urinary bladder
There is similar root term used for bladder: [-vesic] from the Latin [vesicae], also meaning "bladder".
Original image by GEMalone (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons. Public domain.
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Hesselbach's triangle
Hesselbach’s triangle is a triangular region in the lower posterior aspect of the anterior abdominal wall (see yellow inset in the image). It is bound medially by the lateral border of the rectus abdominis muscle, superolaterally by the inferior (deep) epigastric vessels (label “C”) and by the inguinal ligament inferolaterally.
Hesselbach’s triangle is described as the area where a direct inguinal hernia will extrude from posterior to anterior, to protrude directly (hence the name) through the external (superficial) inguinal ring.
Franz Kaspar Hesselbach (1759-1816) was a German surgeon and anatomist who described inguinofemoral hernias in detail, publishing several books on the subject. His name is attached to several regions and structures:
• Hesselbach’s triangle, described in this article
• Hesselbach’s fascia. Known as the cribriform fascia, this perforated fascia covers the saphenous opening in the superior femoral region.
• Hesselbach’s ligament. Also known as the interfoveolar ligament, this is a thickening of the transversalis fascia in relation to the inferior (deep) epigastric vessels.
If you click on the picture, an original image by Hesselbach will appear. This image shows a defect in Hesselbach’s triangle, setting the stage for a direct inguinal hernia, as well as the interfoveolar ligament. Incidentally, Hesselbach's triangle as described today is not the area described originally by Dr. Hesselbach, where the lower border of the triangle was Cooper's ligament.
Initial image property of:CAA.Inc.. Artist:M. Zuptich. Secondary image by F.K. Hesselbach.
Clinical anatomy of the inguinofemoral hernias, as well as abdominal and perineal hernias are some of the lecture topics developed and delivered to the medical devices industry by Clinical Anatomy Associates, Inc. For more information Contact Us.
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The suffix [-plasia] originates from the Greek word [plasis] or [plassein], meaning "to form", or "to develop". In medical terminology the suffix [-plasia] is used to mean "development". Here are some applications of this term:
- Aplasia: the prefix [a-] means "absence of" or "no", therefore "no development", or "no formation"
- Dysplasia: the prefix [dys-] means "abnormal" - abnormal development
- Hyperplasia: the prefix [hyper-] means "excessive" - excessive development
- Neoplasia: the prefix [neo-] means "new", therefore "a new development" or a "new formation". The term [neoplasia] is used to denote a malignant condition, a cancer tumor.
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UPDATED: The eponymic [Thebesian valve], or valve of the coronary sinus is a fold of endocardial tissue situated at the exit ostium of the coronary sinus. Named after Adam Christian Thebesius, the morphology of the valve presents with anatomical variations that go from total absence (see image here) to endocardial folds that cover up to 65% of the coronary sinus opening (see image in this article). The variations of the Thebesian valve include fenestrations, cribiriform valves, and the presence of pectineal cardiac muscle.
The Thebesian valve is important because it can be an obstruction to the passage of a catheter performing retrograde cardioplegia in electrophysiological studies, catheter ablation, and percutaneous mitral valve repair.
Thanks to Dr. Karuna Katti for allowing us the use of the image in this article. The image shows the interior of the right atrium with the inferior vena cava removed to demonstrate the Thebesian valve. In this case, the Thebesian valve covers >65% of the coronary sinus ostium. A catheter is being passed from the superior vena cava into the coronary sinus ostium.
The image shown a human heart with the right atrium and ventricle opened. VC, inferior vena cava; SVC, superior vena cava; TV, Thebesian valve.
Source:"The Thebesian Valve: Gatekeeper to the Coronary Sinus"Karuna Katti and Nikhil Prakash PatilClin Anat 25:379–385 (2012)
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[Dysmorphism] is a medical term formed by the prefix [dys-] meaning "abnormal", the root term [-morph-], arising from the Greek word [μορφος] (morfos), meaning "form" or "shape", and the suffix [-ism], also of Greek origin, in this case meaning "condition". A condition of abnormal shape, or "misshapen".
The term dysmorphism is used to denote an anatomical anomaly, usually superficial, that goes beyond the objective (and sometimes subjective) boundaries of normalcy. An example of these are craniofacial dysmorphisms associated with specific congenital disorders, such as Crouzon syndrome; birth defects such as hemifacial microsomia, or as in the case of the image on this article, Mevalonate Kinase Deficiency, a metabolic disease.
Some craniofacial dysmorphisms can affect articulation and speech, such as cleft palate, cleft lip (harelip), prognathism, and retrognathism.
Dysmorphism is also used in some mental disorders where the patient has an abnormal self-image, seeing his/her body or body parts as abnormal, when they are not. This is known as Body Dysmorphic Disorder (BDD), and can be associated with obsessive-compulsive behavior, anxiety, or depression. In some cases BDD can be associated or found in eating disorders such as Anorexia Nervosa, or bulimia.
The image shows a small child with mevalonic aciduria, a deficiency of mevalonate kinase deficiency. This is a rare genetic autosomal recessive metabolic disorder.
Thanks to Maria E. Gallegos, Chair of the Speech Pathology School, Iberoamerican University, Santiago Chile, for suggesting this article. Dr. Miranda
Image Source: Haas D, Hoffmann GF. Mevalonate kinase deficiencies: from mevalonic aciduria to hyperimmunoglobulinemia D syndrome. Orphanet J Rare Dis. 1, 13. 2006. PMID 16722536. DOI:10.1186/1750-1172-1-13 Image in the public domain
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Coccyx, anterior view
The word [coccyx] arises from the Greek term [κούκος] (pronounced koúkos)and means "cuckoo". It is the name of the lower segment of the spinal column, and was named by Herophilus of Alexandria (325-255BC) because of a resemblance of this structure to the bill of the cuckoo bird. Vesalius also used the same analogy. There is another structure of the body named after the beak of a bird, do you know it? If not, click here.
The coccyx (vernacularly known as "tailbone") is usually represented by four rudimentary vertebrae, although the number varies between 3 to 5 vertebrae. There have been reported cases of "human tails" but these do not have a bony structure and are usually related to congenital abnormalities such as spina bifida.
The coccyx has a well-formed superior component, which usually presents with two cornua (horns) which serve as part of a rudimentary zygapophyseal (facet) joint. The lower coccygeal vertebra is usually a small bony node.
The coccyx has an anterior sacrococcygeal ligament, which is continued with the anoccygeal raphe, a ligamentous structure that serves as a posterior attachment for muscular components of the pelvic diaphragm, and helps anchor the anal canal. The coccygeus muscle, the posterior component of the pelvic diaphragm and part of the sacrospinous ligament also attach to the anterolateral aspect of the coccyx.
Coccygeal pain is referred to as coccydynia.
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. "Dorlands's Illustrated Medical Dictionary" 26th Ed. W.B. Saunders 1994
5 "Tratado de Anatomia Humana" Testut et Latarjet 8 Ed. 1931 Salvat Editores, Spain
6. "Anatomy of the Human Body" Henry Gray 1918. Philadelphia: Lea & Febiger
Image modified by CAA, Inc. Original image courtesy of bartleby.com
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