. A laboratory manual and text-book of embryology. Embryology. EARLY DEVELOPMENT OF THE HEART AND PAIRED BLOOD-VESSELS 257 and myocardium (muscle layer of heart). This type of heart occurs in human em- bryos of 2 mm. and 5 and 6 somites (Fig. 249) and shows three regions: (1) the atrium, which receives the blood from the primitive veins, (2) the ventricle, (3) the bulb, from which is given off the ventral aorta. As the cardiac tube grows faster than the pericardial cavity in which it lies it bends to the right, the bulbus ,-: x and ventricle forming a U-shaped loop (Fig. 250, A, B). Four regio
. A laboratory manual and text-book of embryology. Embryology. EARLY DEVELOPMENT OF THE HEART AND PAIRED BLOOD-VESSELS 257 and myocardium (muscle layer of heart). This type of heart occurs in human em- bryos of 2 mm. and 5 and 6 somites (Fig. 249) and shows three regions: (1) the atrium, which receives the blood from the primitive veins, (2) the ventricle, (3) the bulb, from which is given off the ventral aorta. As the cardiac tube grows faster than the pericardial cavity in which it lies it bends to the right, the bulbus ,-: x and ventricle forming a U-shaped loop (Fig. 250, A, B). Four regions may now be distinguished: (1) the sinus venosus; (2) the atrium, also thin walled and lying cranial to the sinus; (3) the thick-walled ven- tricular limb, ventrad and caudad in position; (4) the bulbar limb, cranial. 'ero Fig. 248.—Diagrams to illustrate the origin of the tubular heart (Strahl and Carius, from McMurrich's " Development of Human Body"), am, amnion; en, entoderm; h, heart; i, digestive 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
Size: 1225px × 2040px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectembryology, bookyear1
