File:Bailey274.jpg

Fig. 274. From a reconstruction of the anlagen of the liver and pancreas and a part of the stomach and duodenum of a human embryo of 4 weeks

Felix.

The liver is the first gland of the digestive tract to appear. In embryos of about 3 mm. a longitudinal ridge-like evagination develops from the entoderm on the ventral side of the gut a short distance caudal to the stomach, that is, in the duodenal portion of the gut (Figs. 247, 272, 273). The cephalic part of the evagination is solid and, being destined to give rise to the liver proper, is called the pars hepatica. The caudal part is hollow, its cavity being continuous with the lumen of the gut, and is destined to give rise to the gall bladder, whence it is called the pars cystica. Beginning at both the cephalic and caudal ends, the evagination as a whole becomes constricted from the gut until (in embryos of about 8 mm.) its only connection with the latter is a narrow cord of cells which is the anlage of the ductus choledochus. The pars hepatica by this time has enlarged considerably and remains attached to the ductus choledochus by a short cord of cells, the anlage of the hepatic duct. The pars cystica has also become larger, its distal portion being somewhat dilated, and is connected with the ductus choledochus by the anlage of the cystic duct (Figs. 274 and 275). The pars cystica grows into the ventral mesentery and thus becomes surrounded by mesodermal tissue. The proximal portion continues to elongate to form the cystic duct and the distal portion becomes larger and more dilated to form the gall bladder.

Current Notes

The links below are to current Embryology pages related to the historical material on this page or file. GIT Links: Introduction | Medicine Lecture | Science Lecture | endoderm | mouth | oesophagus | stomach | liver | gallbladder | Pancreas | intestine | mesentery | tongue | taste | enteric nervous system | Stage 13 | Stage 22 | gastrointestinal abnormalities | Movies | Postnatal | milk | tooth | salivary gland | BGD Lecture | BGD Practical | GIT Terms | Category:Gastrointestinal Tract GIT Histology Links: Upper GIT | Salivary Gland | Smooth Muscle Histology | Liver | Gallbladder | Pancreas | Colon | Histology Stains | Histology | GIT Development Historic Embryology - Gastrointestinal Tract   1878 Alimentary Canal | 1882 The Organs of the Inner Germ-Layer The Alimentary Tube with its Appended Organs | 1884 Great omentum and transverse mesocolon | 1902 Meckel's diverticulum | 1902 The Organs of Digestion | 1903 Submaxillary Gland | 1906 Liver | 1907 Development of the Digestive System | 1907 Atlas | 1907 23 Somite Embryo | 1908 Liver | 1908 Liver and Vascular | 1910 Mucous membrane Oesophagus to Small Intestine | 1910 Large intestine and Vermiform process | 1911-13 Intestine and Peritoneum - Part 1 | Part 2 | Part 3 | Part 5 | Part 6 | 1912 Digestive Tract | 1912 Stomach | 1914 Digestive Tract | 1914 Intestines | 1914 Rectum | 1915 Pharynx | 1915 Intestinal Rotation | 1917 Entodermal Canal | 1918 Anatomy | 1921 Alimentary Tube | 1932 Gall Bladder | 1939 Alimentary Canal Looping | 1940 Duodenum anomalies | 2008 Liver | 2016 GIT Notes | Historic Disclaimer Human Embryo: 1908 13-14 Somite Embryo | 1921 Liver Suspensory Ligament | 1926 22 Somite Embryo | 1907 23 Somite Embryo | 1937 25 Somite Embryo | 1914 27 Somite Embryo | 1914 Week 7 Embryo Animal Development: 1913 Chicken | 1951 Frog

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Reference

Bailey FR. and Miller AM. Text-Book of Embryology (1921) New York: William Wood and Co.

Cite this page: Hill, M.A. (2024, April 19) Embryology Bailey274.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Bailey274.jpg

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