Andreas Vesalius (1515-1564) on animal cognition.

Until well in the 19th century, the Aristotelian concept of the scala naturae (ladder of nature) was the most common biological theory among Western scientists. It dictated that only humans possessed a rational soul that provided the ability to reason and reflect. Michel Eyquem de Montaigne (1533-1592) was the first philosopher influential enough to lastingly posit that animals are cognitive creatures. His view stirred a fierce controversy, with René Descartes (1596-1650) leading among his many adversaries. Only after it became accepted that animals and humans alike have cognitive abilities, did the research on the influence of conscious awareness and intention on the behavior of an animal become possible in the 20th century. We found the anatomist Andreas Vesalius (1515-1564) to have already rejected the Aristotelian view on the lack of the rational soul in animals in his 1543 opus magnum De Humani Corporis Fabrica Libri Septem. His observation "that there is a difference in size according to the amount of reason that they seem to possess: man's brain is the largest, followed by the ape's, the dog's, and so on, corresponding to the amount of rational force that we deduce each animal to have" resonated some 330 years later when Darwin concluded that "the difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind." We conclude that Vesalius was instrumental in breaking with two millenniums of dominance of the concept of lack of animal cognition.

Andreas Vesalius' 500th Anniversary: Initial Integral Understanding of Voice Production.

BACKGROUND: Voice production relies on the integrated functioning of a three-part system: respiration, phonation and resonance, and articulation. To commemorate the 500th anniversary of the great anatomist Andreas Vesalius (1515-1564), we report on his understanding of this integral system. METHODS: The text of Vesalius' masterpiece De Humani Corporis Fabrica Libri Septum and an eyewitness report of the public dissection of three corpses by Vesalius in Bologna, Italy, in 1540, were searched for references to the voice-producing anatomical structures and their function. We clustered the traced, separate parts for the first time. RESULTS: We found that Vesalius recognized the importance for voice production of many details of the respiratory system, the voice box, and various structures of resonance and articulation. He stressed that voice production was a cerebral function and extensively recorded the innervation of the voice-producing organs by the cranial nerves. CONCLUSIONS: Vesalius was the first to publicly record the concept of voice production as an integrated and cerebrally directed function of respiration, phonation and resonance, and articulation. In doing so nearly 500 years ago, he laid a firm basis for the understanding of the physiology of voice production and speech and its management as we know it today.

Andreas Vesalius' understanding of pulmonary ventilation.

The historical evolution of understanding of the mechanical aspects of respiration is not well recorded. That the anatomist Andreas Vesalius (1515-1564) first recorded many of these mechanics in De Humani Corporis Fabrica Libri Septem has received little attention. We searched a digital copy of De Fabrica (1543) and its English translation as provided by Richardson and Carman (1998-2009) for references to aspects of pulmonary ventilation. We found that Vesalius grasped the essentials of tidal and forced respiration. He recognized that atmospheric pressure carried air into the lungs, approximately 100 years before Borelli did. He described an in vivo experiment of breathing, some 120 years before John Mayow produced his artificial model. He reported on positive pressure ventilation through a tracheotomy and on its life-saving effect, some 100 years before Robert Hook did. In publicly recording his insights over 450 years ago, Vesalius laid a firm basis for our understanding of the physiology of respiration and the management of its disorders.

Andreas Vesalius' 500th Anniversary: First Description of the Mammary Suspensory Ligaments.

Sir Astley Paston Cooper has, to date, been acknowledged to be the first to describe the suspensory ligaments of the breast, or Cooper's ligaments, in 1840. We found these ligaments to be recorded in the first edition of 'De Humani Corporis Fabrica Libri Septem' by Andreas Vesalius, published in 1543. To commemorate Vesalius' 500th birthday, we quote and discuss this earlier record. Vesalius' record of the nature and function of the fleshy membrane between mammary gland and pectoral muscle, the hard fat intervening the mammary glands, and the fibers running from the fleshy membrane to the skin are a clear representation of posterior layer of the superficial fascial system, the fibro-adipose stroma surrounding and linking the mammary glandular elements, and the suspensory ligaments as we know them. Vesalius recorded the anatomy and function of the latter structures nearly 300 years before Sir Astley Paston Cooper did.

Andreas Vesalius' 500th Anniversary: Initiation of the Superficial Facial System and Superficial Musculoaponeurotic System Concepts.

Because of their relevance for liposuction and rhytidectomies, respectively, the superficial fascial system (SFS) and superficial musculoaponeurotic system (SMAS) have been thoroughly studied over the past decennia. Although it is well known that the SMAS concept was introduced by Tessier in 1974, it remains unknown who first properly described the stratum membranosum of the SFS. In light of the 500th birthday of Andreas Vesalius (1515-1564), we searched his 1543 masterwork De Humani Corporis Fabrica Libri Septem and related work for references to these structures. We found ample reference to both structures as the membrana carnosa (or fleshy membrane) in his works and concluded that Vesalius recognized the extension, nature, and functions of the stratum membranosum of the SFS, as well as its more musculous differentiation as the SMAS in the head and neck area, and the dartos in the perineogenital area. In doing so, Vesalius recorded most details of the SFS and SMAS concepts avant la lettre.

The first description of the absence of the palmaris longus muscle.

BACKGROUND: While Realdo Colombo from Cremona, Italy has, to date, been acknowledged to be the first to describe the possible absence of the palmaris longus muscle in men in 1559, the authors found this absence to be recorded in the first edition of "De Humani Corporis Fabrica Libri Septum" by Andreas Vesalius, published in 1543. METHOD: To commemorate Vesalius' 500th birthday, this earlier record is quoted and discussed. RESULTS AND CONCLUSION: It remains unknown whether the observation on the absence of the palmaris longus was first done by Vesalius or was based on joined work by Vesalius and Colombo.

Andreas Vesalius' five hundreth anniversary: initiation of the rotator cuff concept.

PURPOSE: The rotator cuff concept refers to the four scapulohumeral muscles that stabilize and rotate the humerus relative to the scapula. To date, the first description of the rotator cuff remained unidentified. METHOD: In light of the 500th birthday of Andreas Vesalius (1515-1564) we searched his 1543 masterwork "Fabrica Corporis Humani Libri Septem" for references to the morphology and function of the rotator cuff muscles. RESULT: Even though he distinguished three rather than four scapulohumeral muscles, Vesalius recognized the need for structures that prevent dislocation of the shoulder inherent to the morphology of the humeral caput and scapular socket. He recorded "three strong ligaments" and the "three muscles that rotate the arm" of which the tendons completely "embrace the ligaments of the joint" as such structures. CONCLUSION: Vesalius defined the rotator cuff concept avant la lettre.