Jean Riolan (the Younger) (15 February 1577 or 1580 – 19 February 1657) was a French anatomist who was an influential member of the Medical Faculty of

Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...

. His father, Jean Riolan (the Elder) (1539–1605) was also a noted French anatomist. Riolan was the personal physician to

Marie de' Medici Marie de' Medici (french: link=no, Marie de Médicis, it, link=no, Maria de' Medici; 26 April 1575 – 3 July 1642) was Queen of France and Navarre as the second wife of King Henry IV of France of the House of Bourbon, and Regent of the Kingdom ...

(1553–1642) for all his life. Riolan is remembered for his traditional views towards medicine, and was a major proponent of the teachings of

Galen Aelius Galenus or Claudius Galenus ( el, Κλαύδιος Γαληνός; September 129 – c. AD 216), often Anglicized as Galen () or Galen of Pergamon, was a Greek physician, surgeon and philosopher in the Roman Empire. Considered to be one of ...

. He held a differing viewpoint in regards to the theory of his contemporary, William Harvey (1578–1657) on the blood's

circulatory system The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...

. Riolan calculated that blood traveled through the blood vessels to the body's extremities and returned to the

heart The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide t ...

only two or three times a day. He also postulated that blood often ebbed and flowed in the veins and that it was taken in as nourishment by different parts of the body. Riolan did not believe that the heart propelled the blood, instead he proposed that the blood kept the heart in motion, analogous to a stream moving the wheel of a water mill. Riolan_and_other_physicians

Riolan had other disagreements with Harvey, such as the role of the

liver The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...

as a blood-manufacturing organ. Riolan was an opponent to the practice of

vivisection Vivisection () is surgery conducted for experimental purposes on a living organism, typically animals with a central nervous system, to view living internal structure. The word is, more broadly, used as a pejorative catch-all term for experiment ...

, asserting that violent and painful deaths suffered by research animals, placed them in an unnatural condition that led to incorrect assumptions about the functionality of healthy animals. Riolan attacked Thomas Bartholin on the question of the latter's discovery of the

lymphatic system The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphatic or lymphoid o ...

. Riolan's best known written works are ''Anthropographia'' (1618), which is a treatise on

human anatomy The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body. It comprises a he ...

, and ''Opuscula anatomica'' (1649), in which he is critical of Harvey's views of the circulatory system. In his ''Anthropographia'' he also defined what traits a good anatomist had to have. The eponymous "

anastomosis An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf#Veins, leaf veins, or streams. Such a connection m ...

of Riolan" is named after him, which is the mesenteric arterial connection between the

superior Superior may refer to: *Superior (hierarchy), something which is higher in a hierarchical structure of any kind Places *Superior (proposed U.S. state), an unsuccessful proposal for the Upper Peninsula of Michigan to form a separate state *Lake ...

and inferior mesenteric arteries. Marginal fibers of the palpebral part of the orbicularis oculi muscle are known as "Riolan's muscle" — also histologically referred to as the "Grey Line." The

cremasteric muscle The cremaster muscle is a paired structure made of thin layers of striated and smooth muscle that covers the testis and the spermatic cord in human males. It consists of the lateral and medial parts. Cremaster is an involuntary muscle, responsibl ...

is also eponymously named after Riolan.

References

External links

''Encheiridium anatomicum et pathologicum''
(1649)
cdlib.org, Chapter 9 Analogical Reasoning: The Model
(Essay about the circulation of the blood). {{DEFAULTSORT:Riolan, Jean 16th-century births 1657 deaths French anatomists 17th-century French physicians