Regnier de Graaf | |
|---|---|
 | |
| Born | 30 July 1641 Schoonhoven, Dutch Republic |
| Died | 17 August 1673 (aged 32) Delft, Netherlands |
| Known for | reproductive biology syringe ovarian follicle |
| Scientific career | |
| Fields | anatomist |
Regnier de Graaf (English spelling), original Dutch spellingReinier de Graaf, or LatinizedReijnerus de Graeff (30 July 1641 – 17 August 1673), was a Dutchphysician,physiologist andanatomist who made key discoveries inreproductive biology. He specialized iniatrochemistry andiatrogenesis,[1] and was the first to develop asyringe to inject dye into human reproductive organs so that he could understand their structure and function.[2]
De Graaf was born inSchoonhoven in aRoman Catholic family, as the son of a carpenter/engineer (equivalent to a modern architect). He studied medicine inLeuven (1658), Utrecht andLeiden (1663).[3][4] There his co-students wereJan Swammerdam,Niels Stensen,Ole Borch andFrederik Ruysch, cooperating with professorFranciscus Sylvius,Johannes van Horne andLucas Schacht. All of them were interested in the organs ofprocreation and influenced by Rene Descartes'iatrophysical approach. He submitted his doctoral thesis on thepancreas, and in 1665 he went (together with his brother) to France where he further experimented on dogs, cooperating withPierre Bourdelot. He obtained his medical degree from theUniversity of Angers withJean Chapelain as his translator.[4] Back in theDutch Republic, De Graaf established himself at Oude Delft. He was studying the male genitalia, which led to a publication in 1668. For his research in theanatomical theatre on theovarian follicle he used female rabbits. (The dissection of corpses was only done in winter, and cadavers were scarce; most were sent to Leiden and available when someone was condemned to death.)
In May 1672 he married Maria van Dijk. As a correspondent of theRoyal Society in London, De Graaf recommended (at the end of April)Henry Oldenburg that attention should be paid toautodidactAntonie van Leeuwenhoek and his work on the improvement of the microscope.[5] De Graaf died on 17 August 1673 and was buried respectfully on 21 August in the nearbyOld Church, Delft on a prominent spot, at the choir.[6][7]
It has been speculated that he may have committed suicide, but it is more likely it was malaria, typhoid fever or dysentery as in other Dutch cities;[8][5] the disease persisted throughout the year, peaking in July and August.
De Graaf's position in the history of reproduction is unique, summarising the work of anatomists before his time, but unable to benefit from the advances about to be made by microscopy, although he reported its use by Antonie van Leeuwenhoek in 1673. His personal contributions include the description of testicular tubules, theefferent ducts, andcorpora lutea. De Graaf may have been the first to understand the reproductive function of thefallopian tube, described thehydrosalpinx, linking its development to femaleinfertility.[9][10] De Graaf also invented a practical syringe, described in his third treatise.
Hiseponymous legacy are theGraafian (or ovarian) follicles. He himself pointed out that he was not the first to describe them, but described their development. From the observation ofpregnancy in rabbits, he concluded that the follicle contained theoocyte, although he never observed it. The mature stage of the ovarian follicle is called theGraafian follicle in his honor, although others, includingFallopius, had noticed the follicles previously (but failed to recognize its reproductive significance). The termGraafian follicle followed the introduction of the termova Graafiana byAlbrecht von Haller who like De Graaf still assumed that the follicle was the oocyte itself, although De Graaf realized the ovum was much smaller. The discovery of the human egg was eventually made byKarl Ernst von Baer in 1827. De Graaf's contemporary Jan Swammerdam confronted him after his publication ofDeMulierum Organis Generatione Inservientibu and accused him of taking credit of discoveries he andJohannes van Horne had made earlier regarding the importance of the ovary and its eggs. De Graaf issued a rebuttal but was affected by the accusation of plagiarism.[11]
De Graaf describedfemale ejaculation and referred to an erogenous zone in the vagina that he himself linked with the maleprostate; this zone was later reported by German gynecologistErnst Gräfenberg and named after him as the Gräfenberg Spot orG-Spot.[12][13] Further, De Graaf described the anatomy of thetesticles and collected secretions of the gall bladder and the pancreas.
Despite his contributions, De Graaf made a number of errors in addition to believing that the ovum was the follicle. He never actually consulted the ancient texts but merely repeated the accounts of others compounding their inaccuracies. Because he observed rabbits rather than humans, he assumed fertilization took place in the ovary. He believed that theseminal vesicles storedspermatozoa.[10] He was not yet aware of the presence of spermatozoa as such; these were discovered just after his death by the Amsterdam student Johannes Ham, using the microscope of Antonie van Leeuwenhoek. Based upon his rabbit experiments and the description of ectopic pregnancy in a lady that had died in her 12th pregnancy in Paris, he assumed that the complete entity was present in the ovary, brought to life by the influence of the male ejaculatory fluid, and then transported to the uterus.
| Fields, disciplines | |
|---|---|
| Theories, concepts | |
| Related | |
