Embryology of the CVS 2 Flashcards
What is the definition of Vasculogenesis and angiogenesis?
Vasculogenesis: New formation of a primitive vascular network
Angiogenesis: The growth of new vessels from pre-existing blood vessels
What are the two first arteries seen?
•right and left primitive aortae
What are the components of each primitive aorta?
Ventral aorta and dorsal aorta
How is the aortic sac produced?
Fusion of ventral aorta
Where do aortic branches arise from?
The aortic sac
What are pharyngeal arteries?
Supply pharyngeal arches
Communicate with aortic branches which are now called aortic arches
Each pharyngeal arch also has its own nerve supply
Pharyngeal arches are the future neck which develop during weeks 4 and 5
How are aortic branches formed?
•Develop from aortic branches and pharyngeal arch arteries
All are not present at the same time, they all terminate at the dorsal aorta
Where do all the aortic arches terminate?
The dorsal aorta
What is the fate of arches 1 and 2?
The 1st and 2nd arches disappear early, remnant of the 1st arch forms part of the maxillary artery (branch of external carotid a.)
What is the fate of arch 3?
The 3rd aortic arch cis the start of the internal carotid a., and is therefore named the carotid arch
What is the fate of arch 4?
The 4th right arch forms the right subclavian,
The 4th left arch constitutes the distal part of aortic arch
What is the fate of the 5th aortic arch?
The 5th arch either never forms or forms incompletely and then regresses.
What is the fate of the 6th aortic arch?
The proximal part of the 6th right arch persists as the proximal part of the right pulmonary artery
The 6th left arch gives off the left pulmonary a. and forms the ductus arteriosus; within 1–3 months, the ductus is obliterated and becomes the ligamentum arteriosum
Summary of the arches
Why do most of the great artery anomalies arise?
As a result of persistence of aortic arches that normally should regress or regression of arches that normally shouldn’t.
What is aberrant subclavian artery?
Right subclavian vein has an abnormal origin on the left side, to supply the arm it must cross the midline behind the trachea and oesophagus which may constrict these organs
What is double aortic arch?
Development of right aortic arch as well as left aortic arch, forming a vascular ring around the trachea and oesophagus whuch usually causes difficulty breathing and swallowing
What is PDA?
Patent ductus arteriosus: Fails to close after birth (would normally form ligamentum arteriosis)
Early symptoms are uncommon, but in the first year of life include increased ‘work of breathing’ and poor weight gain. An uncorrected PDA may lead to congestive heart failure with increasing age.
What is coarctation of the aorta?
Congenital condiditon
Aorta is narrow usually in the area where the ducts arteriosis inserts
What does coarctation mean?
Narrowing