Embryology - 19 Apr 2024 Expand to Translate
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العربية \| català \| 中文 \| 中國傳統的 \| français \| Deutsche \| עִברִית \| हिंदी \| bahasa Indonesia \| italiano \| 日本語 \| 한국어 \| မြန်မာ \| Pilipino \| Polskie \| português \| ਪੰਜਾਬੀ ਦੇ \| Română \| русский \| Español \| Swahili \| Svensk \| ไทย \| Türkçe \| اردو \| ייִדיש \| Tiếng Việt These external translations are automated and may not be accurate. (More? About Translations)

Keibel F. and Mall FP. Manual of Human Embryology II. (1912) J. B. Lippincott Company, Philadelphia.

Historic Disclaimer - information about historic embryology pages
Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding. (More? Embryology History \| Historic Embryology Papers)

II. The Development of the Heart

By JULIUS TANDLER.

The earliest developmental processes of the heart, especially in so far as they concern the formation of the endothelium of the heart and vessels, are unknown in the human embryo, but probably one will not be far astray in assuming that the earliest anlage of the human heart is essentially similar to that of the mammalia. The earliest development of the heart is naturally associated with the first appearance of the vessels, but concerning this the following brief statement is all that is necessary here. According to the comprehensive investigations of Mollier, the preliminary to the formation of the heart in all craniote vertebrates is the appearance of a number of cells between the endoderm and mesoderm, at first in the distal portion of the head. These elements, known as vascular cells, are discernible much earlier in the amniota than in the anamnia, and are recognizable in mammalian embryos with two or three primitive somites. From these vascular cells there develops, however, only the cardiac endothelium, the remaining constituents of the heart wall, the myocardium and epicardium, being derivatives of the visceral ccelomic wall. The first aggregation of the vascular cells of the heart is paired and produces a bulging of the visceral lamella into the wide pleuropericardial cavity. This bulging portion of the wall, which, as already stated, gives rise to the entire heart wall with the exception of the endothelium, has been named by Mollier the heart plate or cardiogenic plate. The topical relation of the paired heart anla^en to one another, that is to say, the time when they come into contact, depends on the configuration of the foregut. If this* is |pread out flat at the time of the appearance of the heart anlagen, these are widely separated from one another; if, however, there is an early closure of the fore-gut ventrally, as, judging from stages already known, is undoubtedly the case in human embryos, then the paired heart anlagen are very close together from the beginning and their fusion takes place early. In the Spee embryo G-le (Normentafel 1 No. 2, primitive somites not yet visible) some scattered vascular cells occur in the region of the paired heart anlage.

Embryology - 19 Apr 2024 Expand to Translate
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العربية \| català \| 中文 \| 中國傳統的 \| français \| Deutsche \| עִברִית \| हिंदी \| bahasa Indonesia \| italiano \| 日本語 \| 한국어 \| မြန်မာ \| Pilipino \| Polskie \| português \| ਪੰਜਾਬੀ ਦੇ \| Română \| русский \| Español \| Swahili \| Svensk \| ไทย \| Türkçe \| اردو \| ייִדיש \| Tiếng Việt These external translations are automated and may not be accurate. (More? About Translations)

Keibel F. and Mall FP. Manual of Human Embryology II. (1912) J. B. Lippincott Company, Philadelphia.

Historic Disclaimer - information about historic embryology pages
Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding. (More? Embryology History \| Historic Embryology Papers)

Book - Manual of Human Embryology 18-2

II. The Development of the Heart