History of Embryology: Difference between revisions

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|1416 BC

|Garbha Upinandas (Hindu text)

|"From the conjugation of blood and semen the embryo comes into existence. During the period favorable to conception, after the sexual intercourse, (it) becomes a Kalada (one-day-old embryo). After remaining seven nights it becomes a vesicle. After a fortnight it becomes a sperical mass. After a month it becomes a firm mass".<ref>Journal of Mammalian Ova Research - [http://www.bioone.org/doi/abs/10.1274/jmor.26.2?journalCode=jmor History of the Egg in Embryology] - 26(1):2-9. 2009  

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|1000 BC

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|460-370 BC

|1st stage: "Sperm is a product which comes from the whole body of each parent, weak sperm coming from the weak parts, and strong sperm from the strong parts."<ref>Section 8, p 321</ref>

2nd stage: "The seed (embryo), then, is contained in a membrane ... Moreover, it grows because of its mother's blood, which descends to the womb. For once a woman conceives, she ceases to menstruate..."<ref>Section 14, p. 326</ref>

3rd stage: "At this stage, with the descent and coagulation of the mother's blood, flesh begins to be formed, with the umbilicus."<ref>Section 14, p. 326</ref><BR>4th stage: "As the flesh grows it is formed into distinct members by breath ... The bones grow hard ... moreover they send out branches like a tree ..."<ref>Section 17, p. 328</ref>

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|"When the material secreted by the female in the uterus has been fixed by the semen of the male...the more solid part comes together, the liquid is separated off from it, and as the earthy parts solidify membranes form all around it...Some of these are called membranes and others choria..."<ref>Aristotle, De Generatione Animalium, Book II, 739b20-739b30, as per Jonathan Barnes (ed.), The Complete Works of Aristotle, (Princeton, 1985), Vol 1, p. 1148.</ref> "So nature has first designed the two blood vessels from the heart, and from these smaller vessels branch off to the uterus, forming what is called the umbilicus...Round these is a skin-like integument, because the weakness of the vessels needs protection and shelter. The vessels join to the uterus like the roots of plants, and through them the embryo receives its nourishment".<ref>Aristotle, De Generatione Animalium, Book II, 740a28-740a35, as per Barnes, opere citato, p. 1149</ref>

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|240-180 BC

|"on the ninth day a few points of blood, on the eighteenth beating of the heart, on the twenty-seventh traces of the spinal cord and head"<ref>Joseph Needham M. A., Ph.D. - [http://www.archive.org/stream/chemicalembryolo01need/chemicalembryolo01need_djvu.txt Chemical embryology] - New York: The Macmillan Company, Cambridge England, at the University Press, 1931 </ref>

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|Claudius Galenus

|"let us divide the creation of the foetus overall into four periods of time.<BR>''The first'' is that in which. as is seen both in abortions and in dissection, the form of the semen prevails [Arabic nutfah]. At this time, Hippocrates too, the all-marvelous, does not yet call the conformation of the animal a foetus; as we heard just now in the case of semen voided in the sixth day, he still calls it semen. But when it has been filled with blood [Arabic alaqa], and heart, brain and liver are still unarticulated and unshaped yet have by now a certain solidarity and considerable size,<BR>this is ''the second period''; the substance of the foetus has the form of flesh and no longer the form of semen. Accordingly you would find that Hippocrates too no longer calls such a form semen but, as was said, foetus.<BR>''The third period'' follows on this, when, as was said, it is possible to see the three ruling parts clearly and a kind of outline, a silhouette, as it were, of all the other parts [Arabic mudghah]. You will see the conformation of the three ruling parts more clearly, that of the parts of the stomach more dimly, and much more still, that of the limbs. Later on they form "twigs", as Hippocrates expressed it, indicating by the term their similarity to branches.<BR>''The fourth and final period'' is at the stage when all the parts in the limbs have been differentiated; and at this part Hippocrates the marvelous no longer calls the foetus an embryo only, but already a child, too when he says that it jerks and moves as an animal now fully formed."<ref>Corpus Medicorum Graecorum: Galeni de Semine (Galen: On Semen) (Greek text with English trans. Phillip de Lacy, Akademic Verlag, 1992) section I:9:1-10 pp. 92-95, 101</ref>

"... The time has come for nature to articulate the organs precisely and to bring all the parts to completion. Thus it caused flesh to grow on and around all the bones, and at the same time ... it made at the ends of the bones ligaments that bind them to each other, and along their entire length it placed around them on all sides thin membranes, called periosteal, on which it caused flesh to grow."<ref>Corpus Medicorum Graecorum: Galeni de Semine (Galen: On Semen) (Greek text with English trans. Phillip de Lacy, Akademic Verlag, 1992) section I:9:1-10 pp. 92-95, 101</ref>

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|The embryo was called peri habbetten (fruit of the body) and develops as:

==See Also==

{{Hub4|Timelines|Timelines}}

{{Hub4|Embryology|Embryology}}