. The development of the chick : an introduction to embryology. Embryology; Chickens -- Embryos. 362 THE DEVELOPMENT OF THE CHICK so that its branches appear secondarily as branches of the inter- nal carotid. The common carotid (car. communis) of adult anatomy is derived entirely from the proximal part of the inter- nal carotid. The Subclavian Artery. The primary subclavian artery arises on the fourth day from the fifteenth (eighteenth of entire series) segmental artery of the body-wall when the wing-bud forms, and grad- ually increases in import- ance with the growth of the wing
. The development of the chick : an introduction to embryology. Embryology; Chickens -- Embryos. 362 THE DEVELOPMENT OF THE CHICK so that its branches appear secondarily as branches of the inter- nal carotid. The common carotid (car. communis) of adult anatomy is derived entirely from the proximal part of the inter- nal carotid. The Subclavian Artery. The primary subclavian artery arises on the fourth day from the fifteenth (eighteenth of entire series) segmental artery of the body-wall when the wing-bud forms, and grad- ually increases in import- ance with the growth of the wing. During the fifth day a small artery that arises from the base of the carotid arch grows backwards and unites with the primary sub- clavian at the root of the wing. Thus the subclavian artery obtains two roots, a primary one from the dorsal aorta and a secondary one from the carotid arch (Fig. 209). As the latter grows in importance the primary root dwindles and finally disappears (about the ninth day). Apparently the Cro- codilia and Chelonia agree Fig. 209. — Disse^ction of the heart and -i i • i • ±u- , . , . , , . ., with the bu'ds m this re- aortic arches of a chick embryo m the latter part of the sixth day of incuba- spect, while the other ver-. tion. (After Sabin.) Au., Auricle. Car. com., Common car- otid. S'cl. d., s., primary and secondary subclavian artery. 3, 4, 6, Third (carotid), fourth (system- ic), and sixth (puhnonary) arches. tebrates retain the primary root. The Aortic System in- cludes the aortic arch and the primitive dorsal aorta with its branches (Fig. 216). The segmental arteries belong to the primitive dorsal aorta; originally ther6 is a pair in each intersomitic septum, but their fate has not been thoroughly worked out in the chick. At six days the cervical segmental arteries are united on each side by. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and
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Keywords: ., bookauthorlilliefrankrat, bookcentury1900, booksubjectembryology
