Paraderm
Historical document, translated for reference. It reflects medical knowledge of the 1920s–30s and is not medical advice.
Summary
This article describes the paraderm, a cell sheet found between the ectoderm and yolk in reptile embryos, which further research identified as entoderm formed between the ectoderm and yolk.
Encyclopedia entry (1928–1936)
PARADERM (from Greek para- near and derma- skin), or yolk sheet (syn. lecithoform), was described by Kupffer and Bencke (Wenischek, 1878; Kupffer, 1882, 1884) as a cell plate lying between the ectoderm and the yolk in reptile embryos. As further research showed, it represents entoderm formed between the ectoderm and the yolk (by the growth of cells). This entodermal plate is formed partly from isolated cells scattered earlier in the blastocele, and partly apparently from a thickened area of the blastoderm, called the primary plate (see), due to vigorous cell multiplication. In the region of the primary plate, the ectoderm and entoderm are thus fused.
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Cite this page
“Paraderm.” Soviet Medical Encyclopedia. English translation of Bolshaya Meditsinskaya Entsiklopediya, 1st ed. (Moscow, 1928–1936), ed. N. A. Semashko. https://sovietmedicalencyclopedia.pages.dev/article/paraderm/