Developmental Anatomy and Anomalies of the Gastrointestinal Tract with Involvement in Major Malformative Syndromes

A clear understanding of normal gastrointestinal development is essential for the understanding of the diseases of the gastrointestinal tract. The following account of the embryology of the human gastrointestinal tract is largely based upon descriptions by numerous authors of staged human embryos in the Carnegie Embryological Collection. Many of these appear in Contributions to Embryology published by the Carnegie Institution of Washington (1915–1966). Of special interest is the series Developmental Horizons in Human Embryos by Streeter (Contrib Embryol 30:211–245, 1942; Contrib Embryol 31:27–63, 1945; Contrib Embryol 32:133–203, 1948; Contrib Embryol 34:165–196, 1951) and Heuser and Corner (Contrib Embryol 36:31–39, 1957). O’Rahilly (Developmental stages in human embryos. Including a survey of the Carnegie collection. Part a: embryos of the first three weeks (stages 1 to 9), Carnegie Institution of Washington, 1973) continued and amplified Streeter’s “Horizons” and renamed them “Stages.” These are now known as the “Carnegie Stages.” O’Rahilly and Muller (Developmental stages in human embryos, Carnegie Institution of Washington, 1987) have supplemented and revised the “Stages,” contributed extensively to the literature of human embryology based on the staged embryos of the Carnegie Collection, and published the third edition of their text (O’Rahilly and Muller, Human embryology and teratology, Wiley-Liss, 2001). Some of their work was utilized extensively in the preparation of this chapter. Classical texts and atlases of descriptive human embryology also used include those of His (Anatomie menschlicher embryonen, T. C. W. Vogel, 1885), Keibel and Mall (Human embryology, J. B. Lippincott Company, 1912), Cullen (Embryology, anatomy, and diseases of the umbilicus. Together with diseases of the urachus, W. B. Saunders Company, 1916), Blechschmidt (The stages of human development before birth. An introduction the human embryology, W. B. Saunders Company, 1961; The human embryo, Freiedrich-Karl Schattauer, 1963; Die pränatalen Organsysteme des Menschen, Hippokrates-Verl, 1973), Gasser (Atlas of human embryos, Harper & Row, 1975; Digitally reproduced embryonic morphology, stage 13. The virtual human embryo, Louisiana State University Health Sciences Center/Armed Forces Institute of Pathology, 2002), Jirasek (Atlas of human prenatal morphogenesis, Martinus Nijhoff Publishers, 1983; An atlas of the human embryo and fetus, The Parthenon Publishing Group, 2001; An atlas of human prenatal developmental mechanics: anatomy and staging, Taylor & Francis, 2004), Kalousek et al. (Pathology of the human embryo and previable fetus, Springer, 1990), England (Life before birth, Mosby-Wolfe, 1996), and Steding (The anatomy of the human embryo: a scanning electron-microscopic atlas, Karger, 2009). Modern studies have added ultrastructural, histochemical, immunohistochemical, and other important details, but with few exceptions, the descriptive embryology of the human gastrointestinal tract established a century ago remains unchanged.