François Pourfour du Petit (24 June 1664 – 18 June 1741) was a French

anatomist Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

ophthalmologist Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a ...

and

surgeon In medicine, a surgeon is a medical doctor who performs surgery. Even though there are different traditions in different times and places, a modern surgeon is a licensed physician and received the same medical training as physicians before spec ...

who conducted careful anatomical studies of the human eye. He also conducted early experiments in neurology. Petit was born in

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

and was orphaned at an early age. He studied the classics at the College de Beauvais before studies in Belgium and Germany. He then studied medicine at the

University of Montpellier The University of Montpellier () is a public university, public research university located in Montpellier, in south-east of France. Established in 1220, the University of Montpellier is one of the List of oldest universities in continuous opera ...

, and afterwards

surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

at the

Hôpital de la Charité Hôpital de la Charité (, "Charity Hospital") was a hospital in Paris founded by the Brothers Hospitallers of St. John of God in the 17th century. In 1935, it was closed and demolished to make way for the new faculty of medicine. Located at 45, ...

in Paris. During this period of time he also attended lectures by

Guichard Joseph Duverney Joseph Guichard Duverney or Joseph-Guichard Du Verney (; 5 August 1648 – 10 September 1730) was a French anatomist known for his work in comparative anatomy and for his treatise on the ear. The fracture of the iliac wing of the pelvis is so ...

(1648–1730) in anatomy and

Joseph Pitton de Tournefort Joseph Pitton de Tournefort (5 June 165628 December 1708) was a French botanist, notable as the first to make a clear definition of the concept of genus for plants. Botanist Charles Plumier was his pupil and accompanied him on his voyages. Li ...

(1656–1708) in

botany Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

. Between 1693 and 1713 he was a military physician in the armies of

Louis XIV LouisXIV (Louis-Dieudonné; 5 September 16381 September 1715), also known as Louis the Great () or the Sun King (), was King of France from 1643 until his death in 1715. His verified reign of 72 years and 110 days is the List of longest-reign ...

, and after the

Peace of Utrecht The Peace of Utrecht was a series of peace treaty, peace treaties signed by the belligerents in the War of the Spanish Succession, in the Dutch city of Utrecht between April 1713 and February 1715. The war involved three contenders for the vac ...

(1713), he returned to Paris as an eye specialist. He conducted many cataract surgeries using the technique of displacing the lens using a needle and influenced

Jacques Daviel Jacques Daviel (11 August 1696 – 30 September 1762) was a French ophthalmologist credited with originating the first significant advance in cataract surgery since couching was invented in antiquity. Daviel performed the first documented planne ...

approach to cataract treatment. He made careful measurements and used biometrical approaches to understanding the eye. He was among the first to note changes in the shape of the lens with age. From 1722 to 1741 he was a member of the

Académie Royale des Sciences The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. It was at the forefront of scientific d ...

: associate member chemist and anatomist in 1722, then resident member anatomist in 1725. Petit is remembered for his detailed anatomical studies of the

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

, as well as

physiological Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ syst ...

research of the

sympathetic nervous system The sympathetic nervous system (SNS or SANS, sympathetic autonomic nervous system, to differentiate it from the somatic nervous system) is one of the three divisions of the autonomic nervous system, the others being the parasympathetic nervous sy ...

. As a military physician, Petit noticed that there was a striking correlation between soldiers' head wounds and

contralateral Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

motor effects, which he documented in a 1710 treatise called ''Lettres d’un medecin des hopitaux du roi a un autre medecin de ses amis''. He was able to conduct ablations in dogs and produce similar effects. He performed pioneer investigations on the internal structure of the

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c ...

, and gave an early, detailed description of the

decussation of the pyramids In neuroanatomy, the medullary pyramids are paired white matter structures of the brainstem's medulla oblongata that contain motor fibers of the corticospinal and corticobulbar tracts – known together as the pyramidal tracts. The lower limit ...

. He also provided the first clinical description of symptoms of the rare

Pourfour du Petit syndrome Pourfour du Petit syndrome (PdPs) is a rare cause of unilateral mydriasis, lid retraction, exophthalmos, and hyperhidrosis. PdPs is typically caused by trauma or tumors that irritate the cervical sympathetic chain, causing ipsilateral symptoms. ...

, which is thought to be closely related to

Horner's syndrome Horner's syndrome, also known as oculosympathetic paresis, is a combination of symptoms that arises when a group of nerves known as the sympathetic trunk is damaged. The signs and symptoms occur on the same side (ipsilateral) as it is a lesion ...

, and also known as reverse Horner syndrome because of its clinical features of mydriasis, eyelid retraction and hyperhidrosis.

Associated eponyms

Neuro-opthalmic syndrome named for Petit: *

Pourfour du Petit Syndrome Pourfour du Petit syndrome (PdPs) is a rare cause of unilateral mydriasis, lid retraction, exophthalmos, and hyperhidrosis. PdPs is typically caused by trauma or tumors that irritate the cervical sympathetic chain, causing ipsilateral symptoms. ...

: a rare cause of unilateral mydriasis, lid retraction, exopthalmos, and hyperhidrosis Anatomical features named after Petit include:Who Named It; François Pourfour du Petit
(biographical information and eponyms) * ''Petit's canals'': Also known as ''spatia zonularia'',

lymph Lymph () is the fluid that flows through the lymphatic system, a system composed of lymph vessels (channels) and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues to be recirculated. At the ori ...

-filled spaces between the fibers of the

ciliary zonule The zonule of Zinn () (Zinn's membrane, ciliary zonule) (after Johann Gottfried Zinn) is a ring of fibrous strands forming a zonule (little band) that connects the ciliary body with the crystalline lens of the eye. The Zonular fibers are viscoela ...

at the equator of the

lens A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements'') ...

of the eye. * ''Petit's sinuses'': Also known as

aortic sinus An aortic sinus, also known as a sinus of Valsalva, is one of the anatomic dilations of the ascending aorta, which occurs just above the aortic valve. These widenings are between the wall of the aorta and each of the three cusps of the aortic va ...

es, the space between each

semilunar valve A heart valve is a biological one-way valve that allows blood to flow in one direction through the chambers of the heart. A mammalian heart usually has four valves. Together, the valves determine the direction of blood flow through the heart. Hear ...

and the wall of the

aorta The aorta ( ; : aortas or aortae) is the main and largest artery in the human body, originating from the Ventricle (heart), left ventricle of the heart, branching upwards immediately after, and extending down to the abdomen, where it splits at ...

References

{{DEFAULTSORT:Petit, Francois Pourfour du French ophthalmologists French anatomists Members of the French Academy of Sciences 1664 births 1741 deaths