A textbook of obstetrics . Visceral layer0/ mesoderm. Entoderm. Fig. 64.—Transverse section of the embryonic area of a fourteen-and-a-half-day ovum of sheep (Bonnet). Axial zone. Neural canal. Somite. Lateral zone. Cavity within somite. Lateral plates forbody-walls. Lateral plates Parietal mesoderm. Pleuroperitonealcavity. Vitelline 65.—Transverse section of a seventeen-and-a-half-day sheep embryo (Bonnet). nopleure. At the end of the second week the development ofthe embryo proper begins, by the formation of the neural folds,the neural canal, the chorda dorsalis, or n
A textbook of obstetrics . Visceral layer0/ mesoderm. Entoderm. Fig. 64.—Transverse section of the embryonic area of a fourteen-and-a-half-day ovum of sheep (Bonnet). Axial zone. Neural canal. Somite. Lateral zone. Cavity within somite. Lateral plates forbody-walls. Lateral plates Parietal mesoderm. Pleuroperitonealcavity. Vitelline 65.—Transverse section of a seventeen-and-a-half-day sheep embryo (Bonnet). nopleure. At the end of the second week the development ofthe embryo proper begins, by the formation of the neural folds,the neural canal, the chorda dorsalis, or notochord, and thesomites, or provertebrae. The normal development of the em-bryonal body now depends, in its gross features, upon an arch-ing-over process of cells which inclose the spinal canal, the PREGNANCY. abdominal and thoracic cavities, and the cranial cavity. Anarrest in these developmental processes results in such deformi-ties as spina bifida, exomphalos, celosoma, hydrencephalocele,and anencephalia. CHAPTER Development of the Embryo and Fetus. The changes in the developing embryo and fetus1 that markits growth from month to month have practical value for the ob-stetrician when he would determine the probable date of im-pregnation from the appearance of the cast-off o
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectobstetrics, bookyear1
