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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 [coronary] comes from the Latin root [corona] meaning "crown", therefore [coronary] is used to denote a structure that surrounds another as a crown or a garland. In the heart, the coronary arteries and their branches form a crown that surrounds the heart at the level of the atrioventricular sulcus. There are two coronary arteries, the right coronary artery (RCA), and the left coronary artery (*). Both these coronary arteries are the only branches that arise from the ascending aorta.
The right coronary artery passes from the anterior to the posterior surface of the heart, ending in a terminal branch, the posterior descending artery, or PDA. The left coronary artery, sometimes called the "left main", gives origin to two branches: the circumflex artery (CFX) and the left anterior descending artery (LAD). Each one of these arteries gives origin to several named branches.
There can be interesting anatomical variations in the coronary arteries of the heart. Heart and coronary artery anatomy is one of the topics developed and delivered by CAA, Inc.
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The Latin word [ventriculus] means "little sac" or "little belly" and arises from the Latin term [venter] meaning "belly" or "abdomen". Originally the term [ventricle] was used to denote the stomach. This use of the word has changed and now the term [ventricle] denotes a "sac" or "cavity", as in the "ventricles of the brain". The term [ventricular] means "pertaining or related to a ventricle".
In the case of the heart, the ventricles represent the two inferior chambers of the heart. (see image, items "C=right ventricle" and "D=left ventricle"). The anatomy of the right and left ventricles is quite different. The left ventricle has a thicker lateral muscular wall, almost three times thicker than the lateral wall of the right ventricle.
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The term [perineum] has two definitions:
1. It is the area of the trunk inferior to the pelvic diaphragm. As such, the perineum contains the ischioanal fossa, the urogenital diaphragm, and the superficial genitalia.
2. It is the area of the body between the upper thighs containing the external openings of urethra, vagina, and anus. This area is delimited (see image) by the symphysis pubis, ischial tuberosities, and coccyx.
The perineum, as described in the second definition, is formed by two large triangular regions. The anterior region (in purple) is called the urogenital triangle, and the posterior region (in yellow) is called the anal triangle.
There is another definition in use that is wrong! Please understand that I post it here as an example only. "The perineum is the area that is found between the scrotum (or vagina) anteriorly and the anus posteriorly". This is NOT the definition of perineum, it is the definition or location of the perineal body, the center of the pelvic floor where 17 named muscles attach of cross. The muscles are:
- Iliococcygeus (2)
- Pubococcygeus (2)
- Superficial transverse perineal (2)
- Deep transverse perineal (2)
- Puborectalis (2)
- Bulbospongiosus (2)
- Pubovaginalis (2)
- Sphincter urethae (1)
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The pelvic diaphragm is one of the four diaphragms in the human body (do you know the other three?) and it represents the lower boundary of the abdominopelvic cavity. This thin and transversely oriented structure is formed from anterior to posterior by the puboccygeus, the iliococcygeus, and the coccygeus muscles.
The first two anterior muscles overlap, the pubococcygeus muscle being superior to the iliococcygeus muscle. Both of them attach laterally to a thickening of the obturator internus fascia that covers the obturator internus muscle. This thickening is known as the arcus tendineus levator ani (ATLA in the image). Because of the relation of the medial fibers of the puboccygeus muscle to the anal canal (puborectalis muscle), and what happens when these muscles contract, these two anterior muscles are known by one common name, the "levator ani" muscle. Click on the picture for a larger image.
The posterior component of the pelvic diaphragm is the coccygeus muscle, which is found lying on the internal aspect of the sacrospinous ligament.
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The root word [-gyne-] is Greek, from [gynaik] meaning "woman" or "female". The suffix [-ology] is also Greek, derived from [logos] meaning "study of". [Gynecology] is then "study of a woman or a female". The term refers to the medical specialty that studies and treats the female reproductive system. A separate specialty, obstetrics, deals with the care of the pregnant patient and delivery of the fetus.
Originally, both specialties were the domain of midwives. It was not until the 1600's that male physicians were allowed to treat gynecological problems and attend births. As the image shows, man-widwifes in Europe were allowed access to the patient only with the use of a "modesty blanket". This is plate XV from the 1681 book "Korte en Bondige Van Der Voortteeling en Kinderbaren" by Samuel Janson.
As an interesting side note in history, the first male physician to work as a man-midwife was Dr. Wertt from Hamburg. Dr Wertt decided to disguise himself as a woman to attend patients. When he was discovered, the punishment was "swift and salutary": He was burned at the stake.
Source:
"The Story of Surgery" by H. Graham, 1939
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From the Greek word [stoma] meaning "mouth or opening", and the suffix [-y] meaning "process or condition". The suffix [-(o)stomy] refers to the "process of creating an opening". This process can be physiological, without intervention, as in the creation of a spontaneous fistula, or it can be a surgical procedure.
As a working explanation of [-ostomy] in surgery, we like to use the term "drainage". Therefore, an [ileostomy] would be the procedure by means of which a drainage opening is creating an anastomosis between the ileum and the abdominal wall.
The accompanying image shows an early 1900's procedure to create a gastrostomy (Wietzel's gastrostomy). The root term [gastr-] means "stomach".