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Medical Terminology Daily (MTD) is a blog sponsored by Clinical Anatomy Associates, Inc. as a service to the medical community, medical students, and the medical industry. We will post a workweek daily medical or surgical term, its 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

Johann Gottfried Zinn

Johann Gottfried Zinn
(1727–1759)

Anatomist and botanist, Johann Gottfried Zinn was born on December 6, 1727 in the city of Ansbach, Germany. He started his medical studies in his native city, becoming later a student of Dr.  Albrecht von Hallers at the University of Göttingen, and received his MD in 1749.

He left for Berlin to continue his studies but came back shortly thereafter. He became a professor of anatomy at the University of Göttingen and in 1753 he also became the director of the botanical garden in the same city.

He is known for his anatomical treatise on the anatomy of the human eye: “Descriptio anatomica oculi humani iconibus illustrata”. Because of this, his name has become an eponym in the “Zonule of Zinn”, a ring of strands that forms a fibrous band connecting the ciliary body with the capsule of the lens of the eye. Zonule of Zinn is sometimes referred to as the suspensory ligaments of the lens, or the “ligament of Zinn”. His name is also attached to the anular ring tendon found in the posterior aspect of the eye, the "anular tendon of Zinn". This ring serves as attachment for all the extraocular muscles of the eye and the optic nerve passes through the center of the ring.

Carol Linné (Carolus Linneaus) named a genus of flowers in the family Asteraceae known vernacularly today as “Zinnia” in his honor. Hover your cursor over his portrait to see the flower.

The chapter on orbital anatomy of his anatomy book, taken from the second edition in 1780, has been translated and the first of three parts is published in an issue of “Strabismus”

His book "Catalogus Plantarum Horti Academici Et Agri" can be seen online here.

His life was short, dying at the early age of 32, but his name lives on in the name of a beautiful flower.

Sources:
1. “Johann Gottfried Zinn" Simonz, HJ Strabismus – 2004, Vol. 12, No. 2, p. 125 
2. "Anatomical Description of the Human Eye" Zinn, JG Strabismus, 13:45–52, 2005 
Images: Public Domain by Wikipedia Commons. 1. Own work I_am Jin, and H. Wilhem Dietz


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An answer regarding the death of Andreas Vesalius (2)


NOTE:  In 2014  Pavlos Plessas presented the compelling theory that Andreas Vesalius died in 1564 from scurvy on the island of Zakynthos. With his permission his original article entitled "Powerful indications that Vesalius died from scurvy" was published in this blog in 2016.

His theory was later challenged by Theo Dirix and Dr. Rudi Coninx in this same blog with the article "Did Andreas Vesalius really died from scurvy?". Pavlos Plessas' rebuttal to the latter article is published here from a letter to Theo Dirix.


...continued from: An answer regarding the death of Andreas Vesalius (1)...

8. Echtius’ treatise was only published after his death in 1556

This is incorrect. Echtius was alive almost a decade after that and heard Boucherus describe Vesalius’ death with his own ears. The treatise was first published in 1564, the year of Vesalius’ death, albeit was wrongly attributed to Wierus.

9. Echtius believed scurvy was caused by a blocked spleen, leading to an excess of black bile

Echtius believed that an excess of black bile (melancholic humour) caused scurvy. He wrote that in addition to eating preserved foods and mouldy biscuit, and drinking foul water, the following conditions led to an excess of black bile: warm air, lack of sleep, hard manual work, anxiety and fevers. Each one individually could cause scurvy even if the diet was good . The reasons for Vesalius’ illness as indicated by the sources are: eating rotten biscuit, drinking corrupt water, hot weather and extreme worrying. Please compare with the list of causes given by Echtius in his treatise.

10. It is claimed that extreme fear and irrational behaviour … are well known early symptoms [Plessas]. This is not the case

Pavlos Plessas
Pavlos Plessas
Click on the image for author information

I quote Rev. Richard Walter of the Anson expedition, who saw many of his shipmates die from scurvy: This disease is likewise usually attended with a strange dejection of spirits; and with shiverings, tremblings, and a disposition to be seized with the most dreadful terrors on the slightest accident (4). 


11. This (absence of extreme fear and irrational behaviour) is also the observation of one of the authors (RC) having observed scurvy patients in Ethiopian prisons

Did any of Dr. Coninx’s patients see other inmates die from scurvy? Did he ever observe one of his patients witness an accident? Were his patients evaluated by a psychiatrist? I would hazard the guess that the answer to all the questions is no. I choose to believe Rev. Richard Walter.

12. The Italian Pietro Bizzari based his account on what he had been told by an anonymous Venetian goldsmith

Bizzari’s account is not credible. It clashes with the accounts of three different people, who saw Vesalius’ grave in Santa Maria delle Grazie.

13. Metellus describes the symptoms of Vesalius’ illness

No, he does no such thing.

14. The possibility of rotten food as a cause of death on the ship is plausible

I hope this is not a suggestion that a great physician like Vesalius could not recognise the symptoms of food poisoning in others. If he did, it would have been possible to identify the particular source and he would not have fallen ill himself. Even if that was not possible they could have resorted to sharing the supplies of the crew, who had suffered no cases of illness. Surely it is best to be malnourished than risk death from food poisoning. In addition, had the cause of death been food poisoning, the sources would not have blamed Vesalius’ worrying for his illness. Finally, since the authors seem to agree that Metellus’ version of events is the most reliable, how is it possible for a man on the verge of death from food poisoning to be walking on the seashore of Zakynthos? Food poisoning as a cause of death is not plausible even though the sources claim the disease was somehow related to food and water shortage.

15. A 1971 study by Kinsman and Hood which allegedly claims that personality changes are amongst the first symptoms of scurvy

Why allegedly? I quote from the study: The personality changes occurred at an earlier stage of depletion than the psychomotor changes, which did not appear until obvious clinical scurvy was present (5). So the study does claim that personality changes are amongst the first symptoms of scurvy, the very first as a matter of fact. According to figure 3 of the study the MMPI T-scores started increasing when the level of Vitamin C in the body was at the equivalent of 761 mg. Clinical signs of scurvy became apparent only when the level went down to 300 mg. 

Article continued here: An answer regarding the death of Andreas Vesalius (3)

Sources:

1. "Voyages and Travels in the Levant in the Years 1749, 50, 51, 52" London 1766, p. 147
2. "Medicina Nautica: an Essay on the Diseases of Seamen" Volume III, London 1803, p. 387
3. "De magnis Hippocratis" Lienibus Libellus, Antwerp 1564, pp. 26a – 31b
4. A voyage round the world in the years MDCCXL, I, II, III, IV, 5th edition, London 1749, p. 101.
5. Robert A. Kinsman and James Hood, Some behavioral effects of ascorbic acid deficiency, The American Journal of Clinical Nutrition, April 1971.
6. Fiona E. Harrison, Behavioural and neurochemical effects of scurvy in gulo knockout mice, Journal for Maritime Research, Volume 15, Issue 1, 2013.
7. Olivier Fain, Musculoskeletal manifestations of scurvy, Joint Bone Spine 72, 2005.
8. Wang et al, Effects of vitamin C and vitamin D administration on mood and distress in acutely hospitalized patients, the American Journal of Clinical Nutrition, 2013.