CVS Embryology PDF : Development of Arteries

Development of arteries th th  During 4 & 5 weeks of development, the aortic sac (lies distal to the truncus arteriosus)  Aortic sac has right and left horns  Horns are continuous with 1st aortic arch  1st aoric arches grow dorsal to the gut forming dorsal arotae  2 dorsal aortae...

Development of arteries th th  During 4 & 5 weeks of development, the aortic sac (lies distal to the truncus arteriosus)  Aortic sac has right and left horns  Horns are continuous with 1st aortic arch  1st aoric arches grow dorsal to the gut forming dorsal arotae  2 dorsal aortae fuse to form common dorsal aorta  Other 5 aortic arches develop cranio-caidally between aortic sac & dorsal aortae DR.Hendawy “ CVS embryology” Fate of: Aortic sac :  Stem :form aortic arch proximal to brachiocephalic artery  Right horn: form brachiocephalic artery  Left horn: form aortic arch between brachiocephalic artery & Left common carotid Aortic arches :  1st aortic arch: forms Maxillary artery  2nd aortic arch: forms Stapedial artery  3rd aortic arch: forms Common carotid & Proximal part of Internal carotid N.B: External carotid “appear as bud”  4th aortic arch:  Right one: forms part of right subclavian  Left one: forms Aortic arch between left common carotid & left subclavian  5th aortic arch: degenerates  6th aortic arch: forms  Pulmonary artery from its proximal part while the distal part degenerates on the right side  Pulmonary artery from its proximal part while the distal part form ductus arteriosus on the left side N.B: course to recurrent laryngeal nerve At First, RLN hooks around the distal part of 6th arch.  Right RLN hooks around 4th arch which form right subclavian as the distal part of 6th & 5th arch degenerate  Left RLN hooks around ligamentum arteriosum “the distal part of 6th arch” Dorsal aorta :  Cranial to 3rd aortic arch: form distal part of internal carotid  Between 3rd & 4th aortic arch degenerate Right side Left side th th  From 4 to 6 aortic arch Right subclavian Arch of aorta distal to subclavian th th  Distal to 6 aortic arch Right subclavian till 7 ISA Descending aorta th Degenerate distal to 7 ISA DR.Hendawy “ CVS embryology” Arch of aorta is formed of: 1. stem of aortic sac “form part from origin to brachiocephalic artery” 2. left horn of aortic sac “form part from brachiocephalic to left common carotid” 3. Left 4th aortic arch “form part from left common carotid to left subclavian” 4. Left dorsal aorta “form part distal to left subclavian artery” Subclavian artery is formed of: 1. Left subclavian: is formed of left 7th inter-segmental artery 2. Right subclavian:  Right 4th aortic arch  Right dorsal arota between 4th aortic arch & Right 7th inter-segmental artery  Right 7th inter-segmental artery DR.Hendawy “ CVS embryology”  Anomalies Patent ductus arteriosus:  It is a common potential cyanotic heart disease.  The duct between the left branch of pulmonary artery and aortic arch remains patent  May be accompanied with other diseases such as Fallot’s tetralogy Aortic coarctation: Constriction of aorta distal to origin of left subclavian It occurs in 10 % of cases of congenital heart diseases There are 2 types: Pre-ductal Post-ductal Coarctation is proximal Coarctation is distal to entrance of ductus arteriosus to entrance of ductus arteriosus The ductus remains open The ductus usually closes Collateral circulation develops. DR.Hendawy “ CVS embryology”