Embryology 2 Flashcards
What is vasculogenesis?
New formation of a primitive vascular network
What is angiogenesis?
Growth of new vessels from pre-existing blood vessels
How is the aortic sac formed?
2 primitive aorta with endothelial heart tube
-> Endothelial heart tubes fuse to form a single primitive heart tube
-> 2 ventral sections of primitive aorta fuse to form the aortic sac
From where do aortic branches arise?
The Aortic sac, they connect to it on one side and the remaining dorsal section of the aorta at the other.
What embryonic structure becomes the neck?
Pharyngeal arches
What do we call the blood and nerve supply of the pharyngeal arches?
Pharyngeal arteries & nerves
What becomes of the 1st aortic arch?
It dissapears early on but its remnants form part of the maxillary artery, a branch of the external carotid artery
What happens to the 2nd aortic arch?
It dissapears entirely early on
Whats the fate of the 3rd aortic arch?
The start of the internal carotid artery, therefore its known as the carotid arch
What happens to the 4th aortic arch?
The left one becomes the distal part of the aortic arch
The right one forms the right subclavian
What becomes of the 5th aortic arch?
It never forms or it does but incompletely and regresses
What happens to the 6th right aortic arch?
It becomes the proximal part of the right pulmonary artery
What happens to the 6th left aortic arch?
It gives off the left pulmonary artery
Then forms the Ductus Arteriosus connecting aorta and pulmonary trunk, to help bypass the lungs
What is the origin and fate of the ductus arteriosus?
The Ductus Arteriosus arises from the 6th left aortic arch.
Within 3 months its obliterated & becomes the ligamentum arteriosum.
What condition arises from regression of the 4th right aortic arch and the right dorsal aorta?
An aberrant subclavian artery, the right subclavian has its origin on the left side on the aortic arch instead of the right.
The right subclavian passes behind the oesophagus & trachea which can constrict them