Development of heart iii
- 1. The Aortic Arches S. B. Rauniyar 5/2/2016
- 2. Embryonic Blood Vessels • By the beginning of the 4th week, an extensive network of blood vessels is formed throughout the embryonic body • The heart begins to beat on 21st or 22nd day, and blood begins to circulate. • This makes the CVS to be the first system in the body to reach the functional state • The embryonic heartbeat can be detected ultrasono- graphically during the 5th week
- 5. Aortic Arches • 1st arteries to appear is primitive aortae consist of a portion lying ventral to foregut( ventral aorta) , an arched portion (1st aortic arch) , & dorsal portion lying dorsal to the gut ( dorsal aorta) • The ventral aorta partially fuse to form aortic sac , unfused part remaining as the right & left horn of aortic sac. • The aortic arches arise from the aortic sac and terminate in the dorsal aorta of the ipsilateral side
- 6. Aortic Arches • Though six pairs of aortic arches usually develop • All are not present at the same time • By the time the sixth pair of aortic arches has formed, the first two pairs disappear • During the eighth week, the aortic arch pattern is transformed to final fetal arterial arrangement • In the region of aortic arches, the dorsal aortae remain paired, but caudal to this region they fuse to form a single median vessel
- 7. Changes in the original aortic arch system
- 8. Changes in the original aortic arch system • Obliteration of: Most of the 1st & 2nd arches 5th arches completely Distal part of the right sixth arch The segment of both dorsal aortae lying between the 3rd & 4th arches ( ductus caroticus ) The segment of right aorta lying between the 7th intersegmental artery & the fused dorsal aortae
- 9. Derivatives of Aortic Arches
- 10. First Pair • Largely disappear • Dorsal part persists as the maxillary arteries which supply the ear, teeth and muscles of the eyes and face • May give rise to the external carotid artery The first arch is obliterated before the 6th arch is formed
- 11. Second Pair • Largely disappear • Dorsal part persists as the hyoid and stapedial arteries
- 12. Third Pair • Proximal part: forms the common carotid arteries • Distal part: joins the dorsal aortae to form the internal carotid arteries
- 13. Third Pair • Each third arch artery gives off a bud that grows cranially to form the External carotid artery
- 14. Fifth Pair • Disappears completely with NO vascular derivatives
- 15. The fate of 4 & 6th pairs of aortic arches differs on the right and left side
- 16. Aortic sac • Aortic sac & left horn : becomes the proximal segment of the Aortic arch • Right horn : becomes the Brachiocephalic artery
- 17. Fourth Pair • RIGHT: Becomes the proximal part of the right subclavian artery • LEFT: Forms part of the arch of aorta
- 18. Arch of Aorta Derived as: • Proximal segment from aortic sac • Middle segment from the left horn of aortic sac • Distal segment from the left 4th aortic arch
- 19. Subclavian Artery • The right subclavian artery formed from the: Right horn of aortic sac & Right 4th aortic arch Right 7th intersegmental artery • The left subclavian artery formed from the left 7th intersegmental artery
- 20. Sixth Pair • RIGHT: :- Proximal part: persists as the proximal part of the right pulmonary artery :- Distal part: degenerates • LEFT: :- Proximal part: persists as the proximal part of the left pulmonary artery :- Distal part: forms ductus arteriosus, a shunt between pulmonary artery and dorsal aorta
- 22. ADULT DERIVATIVES OF FETAL VESSELS Umbilical vein becomes the ligamentum teres hepatis. Umbilical arteries( rt <) :-- • proximal part superior vesicle arteries • distal part medial umbilical ligaments. . Ductus venosus ligamentum venosum, Foramen ovale fossa ovalis Ductus arteriosus ligamentum arteriosum
- 23. 14 Feb 2009 23 Anomalies of Aortic Arches Patent ductus arteriosus
- 24. 14 Feb 2009 24 Coarctation of aorta Types
- 25. 14 Feb 2009 25 Abnormal origin of right subclavian artery: Types
- 26. 14 Feb 2009 26 Double aortic arch
- 27. 14 Feb 2009 27 Right aortic arch
- 28. 14 Feb 2009 28 Interrupted aortic arch
- 29. 14 Feb 2009 29 Persistent ductus caroticus