. A laboratory manual and text-book of embryology. Embryology. LATERAL DISSECTION OF THE VISCERA IO3 the pharyngeal pouches. The pouches have each a dorsal and ventral diverti- culum (Fox, Thyng). The dorsal diverticula are large and wing-like (Fig. 99), meet the ectoderm of the gill clefts, fuse with it and form the closing plates. Between the ventral diverticula of the third pouch lies the median thyreoid adage. The fourth pouch is much smaller than the others. Its dorsal diverticu- Eye Maxillary process Mouth Br. arch 3 Br. arch 4 Upper limb bud Hepatic diverticulum Yolk-sac Body-stalk Alla
. A laboratory manual and text-book of embryology. Embryology. LATERAL DISSECTION OF THE VISCERA IO3 the pharyngeal pouches. The pouches have each a dorsal and ventral diverti- culum (Fox, Thyng). The dorsal diverticula are large and wing-like (Fig. 99), meet the ectoderm of the gill clefts, fuse with it and form the closing plates. Between the ventral diverticula of the third pouch lies the median thyreoid adage. The fourth pouch is much smaller than the others. Its dorsal diverticu- Eye Maxillary process Mouth Br. arch 3 Br. arch 4 Upper limb bud Hepatic diverticulum Yolk-sac Body-stalk Allantois Umbilical artery Mesonephric duct. Fr onto-nasal process 'Olfactory pit Mandibular process Br. arch 2 Aortic bulb Trachea Lung bud Stomach Cephalic loop of intestine Mesonephros Mesonephric duct Caudal loop of intestine Lower limb bud -Recluri Dorsal aorta and umbilical artery Fig. 92.—A ventral dissection of a 6 mm. pig embryo. The head has been bent dorsally. Br. arch 2, 5 and 4, branchial arches, 2, 3 and 4. lum just meets the ectoderm, its ventral portion is small, tubular in form and is directed parallel to the esophagus (Fig. 99). The groove on the floor of the pharynx caudal to the epiglottis is continu- ous with the tracheal groove. More caudally opposite the atrium of the heart the trachea has separated from the esophagus. The trachea at once bifurcates to form the primary bronchi, and the anlages of the lungs. The lungs consist merely of the dilated ends of the bronchi surrounded by a layer of splanchnic mesoderm. They bud out laterally on each side of the esophagus near the cardiac end of the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Prentiss, Charles William, 1874-1915. Philadelphia, London, W. B. Saunders
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectembryology, bookyear1
