. Carnegie Institution of Washington publication. 82 AORTIC-ARCH SYSTEM IN THE HUMAN EMBRYO. a vertebra length more caudally. The larger and more rapidly moving arch has apparently aided in the movement of the pharyngeal tissue which lies in its path. Kingsbury has pointed out that the shifting of even the pharyngeal derivatives is in part due to their own outgrowth. In a succeeding discussion, based on models prepared to show the rudimentary ribs and sternal bands as well as arteries, it will be seen that the changes in the ribs are also somewhat suggestive of material in the growth eddy. REL
. Carnegie Institution of Washington publication. 82 AORTIC-ARCH SYSTEM IN THE HUMAN EMBRYO. a vertebra length more caudally. The larger and more rapidly moving arch has apparently aided in the movement of the pharyngeal tissue which lies in its path. Kingsbury has pointed out that the shifting of even the pharyngeal derivatives is in part due to their own outgrowth. In a succeeding discussion, based on models prepared to show the rudimentary ribs and sternal bands as well as arteries, it will be seen that the changes in the ribs are also somewhat suggestive of material in the growth eddy. RELATION OF MIGRATING ARCH AND ITS BRANCHES TO SUPERIOR APERTURE OF THORAX. The approach and entrance of the heart and its arterial vessels into the thorax is characterized bjr a nice coordination between the time of arrival of the Vertebral art. Vertebral art Common carotid art. Innominate art. Subclavian Da. Figs. IS to The descent of the fourth aortic arch and the definitive aortic arch into the thorax, shown in relation to the cervical vertebra? and ribs. Asterisk, so-called fifth aortic arch; 4, fourth aortic arch; d. a., definitive aortic arch; R. 1, first rib; in. art., innominate artery; c. r., cervical rib; c. c, common carotid; v. art., vertebral artery; a. r., remnant of segment of dorsal aorta, interrupted between third and fourth aortic arches; sub. art., subclavian artery. In figures 20 and 24 the sternal bands are not yet in contact above and the definitive aortic arch has a large radius of curvature. In figures 21 and 25 the bands have met and the arch has become sharply bent by the swinging dorsally of the heart. heart and aortic arch at the thorax and the coming together of the ribs and sternum in front. Within an interval of 10 days the upper ribs on each side, capped by their sternal bands, have completed the thoracic arch (figs. 18 to 25). In the 14-mm. embryo the ribs are slightly concave cranially and nearly straight in the transverse plane. By th
Size: 2243px × 1114px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1900, bookyear1902
