Reliable URLs for Human Embryology: The Carnegie Stages of Early Human Embryonic Development

Dianne N. Irving
Copyright April 20, 2011
Reproduced with Permission

As most people understand clearly by now, for several decades the long-known and long-documented accurate scientific facts of the development of sexually reproduced human embryos (from the beginning of the process of fertilization through the end of eight weeks) and when they begin to exist have not been taught, or have been misunderstood or even creatively distorted - for various reasons. Likewise, the same is also true concerning human embryos who have been asexually reproduced (without the immediate use of sperm or oocytes), e.g., naturally occurring identical twins asexually reproduced in vivo, and those human embryos asexually reproduced by various cloning and other genetic engineering techniques, including artificial "twinning", SCNT, GLCNT, pronuclei transfer, etc., in vitro.

The purpose of this brief article is to provide to those who are interested three of the most reliable sources online today for the accurate scientific facts of sexually reproduced human embryos - the Carnegie Stages of Early Human Embryonic Development. (Note: unfortunately, there are quite a number of websites that use the "name" of the Carnegie Stages, but the "science" that they then present is not in concert with and even contradicts the accurate scientific facts as documented by the genuine Carnegie Stages). Even within these Carnegie Stages reference is made to the post-fertilization asexual reproduction and development of one of every pair of new identical twins naturally reproduced in vivo (see Stages 2 through 5). [For a brief explanation of the science involved in both sexually and asexually reproduced human embryos, see the short article by Kischer and Irving.[1] For a short list of related articles concerning the use of the accurate scientific facts of human embryology, see those listed in the endnote].[2]

One would hope that these are the accurate scientific facts that are used to describe human embryonic development in vivo (including descriptions of "prenatal development") and in vitro, for either sexually or asexually reproduced human embryos. One would also hope that these are also the accurate scientific facts that are used as the "starting points" for deriving any legitimate positions in philosophy, theology, bioethics, sociology, medicine, scientific research, etc., and in determining public policies, laws, regulations and other legal documents concerning the early human embryo. Starting with false scientific "facts" about the human embryo necessarily leads to different and erroneous positions, policies and laws.

Some of the websites listed below are easier to use than others, so short explanations are provided. The three websites recommended are the following:

(1) The original Carnegie Stages at the National Museum of Health and Medicine (Human Developmental Anatomy Center), which also gives the history of the science of human embryology and the institutionalization of the Carnegie Stages in 1942;

(2) The most recent updating of the Carnegie Stages online (Jan. 2011) by the international nomenclature committee on human embryology, i.e., the Terminologia Embryologica Committee (TE) which has operated internationally and updated the Carnegie Stages continuously since 1942 to the present; and

(3) The new website, "The Virtual Human Embryo", housed at the Louisiana State University's Health Sciences Center (probably the easiest to follow).

Reliable URL's For the Carnegie Stages:

1. The Carnegie Stages of Early Human Embryonic Development, at the National Museum of Health and Medicine (Human Developmental Anatomy Center).

The known facts of the science of human embryology are not "new". The first to study the human embryo systematically was Wilhelm His, Sr., who established the basis of reconstruction, i.e., the assembling of three-dimensional form from microscopic sections. His, who has been called the "Vesalium of human embryology," published his three-volume masterpiece Anatomie menschlicher Embryonen in 1880-85 [His, Vogel, Leipzig]. In it the human embryo was studied as a whole for the first time. A detailed Handbook of Human Embryology by Keibel and Mall appeared in 1910-12. Franklin P. Mall, who studied under His, established the Carnegie Embryological Collection in Baltimore and was the first person to stage human embryos (in 1914). Mall's collection soon became the most important repository of human embryos in the world and has ever since served as a "Bureau of Standards" for the science of human embryology. Mall's successor, George L. Streeter, laid down the basis of the currently used staging system for human embryos (1942-48), which was instituted in 1942, completed by O'Rahilly (1973) and revised by O'Rahilly and Muller (1987). (Ronan O'Rahilly and Fabiola Muller, Human Embryology & Teratology (New York: Wiley-Liss, 2001); also, O'Rahilly and Muller, ibid., (3rd ed., 1994), p. 3.

See the current website of the Human Development Anatomy Center: http://nmhm.washingtondc.museum/collections/hdac/Education_Projects.htm. This is also the home of the Carnegie Stages of Early Human Embryonic Development. See Carnegie Stage One (phases a, b, and c) at: http://nmhm.washingtondc.museum/collections/hdac/stage1.pdf; see all 23 stages of the early developing human embryo at: http://nmhm.washingtondc.museum/collections/hdac/Select_Stage_and_Lab_Manual.htm. Click into the "textbook" at the bottom left side of the screen to access more extensive details of each stage and the extensive scientific references.

2. The most recent updating of the Carnegie Stages (Jan. 2011) by the international nomenclature committee on human embryology, i.e., the Terminologia Embryologica Committee.

To use this new website for the Terminologia Embryologica online go to FIPAT, at: http://www.unifr.ch/ifaa/. Click on "Free access to published terminologies", "Enter" to get to: http://www.unifr.ch/ifaa/Public/EntryPage/HomePublic.html. You are now on the Public Entry Page; Click into "Source terminologies as originally published", to get to: http://www.unifr.ch/ifaa/Public/EntryPage/ViewSource.html. This page lists the 3 Terminologias; To the right of the page, under "Terminologia Embryologica, from internal document (2009)", Click on e2.0: "Ontogeny" to get to: http://www.unifr.ch/ifaa/Public/EntryPage/ViewTE/TEe02.html. You are viewing "Page 8"; now use buttons at top right to move to Page 10 to arrive at description of Carnegie Stages 1-5 in Chart; The right side of chart provides the following documentation of the first 5 Stages; see especially "Single cell EMBRYO [St. 1].

3. "The Virtual Human Embryo", developed by human embryologist Dr. Ray Gasser (a member of the international nomenclature committee), and housed at the Cell Biology and Anatomy Department, Louisiana State University's Health Sciences Center, at: http://virtualhumanembryo.lsuhsc.edu/.

To access the various stages of the new sexually reproduced developing human embryo from their main page by clicking the "DREM Project" at the middle-left of the page, which brings you to: http://virtualhumanembryo.lsuhsc.edu/DREM/DREM_home.htm. From there click "Enter"; and then click into "Demo" on the left of the page. This brings you to a listing of all the Carnegie Stages.

Hopefully these websites will be found helpful for those working on issues involving the early human embryo.


Endnotes:

Top