Great Vessels Embryo Flashcards
When does vasculogenesis begin and what are the steps?
End of third week, hemangioblasts aggregate and form blood islands (endothelial precursor cells lining hematopoietic progenitor cells), channels forms within plexuses, then the channels enlarge and unite to form arteries and veins
When is the 1st aortic arch formed?
4th week, supplies the 1st pharyngeal arch
What are the branches of the fused dorsal aorta?
- ventral segmental arteries (supply splanchnic LP and endoderm)
- lateral segmental arteries (supply intermediate mesoderm)
- dorsal segmental arteries (supply somites)
When do the rudiments of the remaining arches form?
Days 26-32
When do the aortic arches complete formation?
Days 32-37, they give of branches to the developing head
What does the 1st aortic arch give rise to?
External carotid, maxillary (jaw area)
What does the 2nd aortic arch give rise to?
Stems of stapedial arteries (ear)
What does the aortic sac give rise to?
Brachiocephalic artery and base of the arch of the aorta
What does the 3rd aortic arch give rise to?
Common carotid and internal carotid arteries
What does the 4th aortic arch give rise to?
Left: medial portion of the arch of the aorta
Right: proximal right subclavian
What does the 6th aortic arch give rise to?
Pulmonary arteries!
- left distal ductus arteriosus
- right distal will degenerate
What do the 7th intersegmental arteries give rise to?
Left: entire subclavian artery
Right: distal part of right subclavian
What does the dorsal aorta give rise to?
Left: descending aorta
Right: proximal portion of the right subclavian artery
What happens when the distal part of the 6th arch degenerates?
On the left: distal 6th arch persists as the ductus arteriosus and the left recurrent laryngeal wraps around it.
The right right: the distal 6th arch degenerates and the right recurrent laryngeal travels farther up and hooks around the right subclavian artery (because there isn’t anything on the left side keeping it in place
When does remodeling of the inflow heart take place?
Weeks 4-8
What does the right horn of sinus venosum give rise to?
Orifice of IVC, orifice of coronary sinus, becomes smooth wall of the atria and crista terminalis
What is the fate of the vitelline veins proximal to heart?
Left vein degenerates, right vein persists as right hepatocardiac channel (IVC from liver to heart)
What is the fate of the vitelline veins within the liver?
Right forms hepatic vein (part of IVC), both right and left form portal vein (from gut)
What is the fate of the umbilical vein?
Right degenerates entirely, left proximal degenerates, distal left persists in embryo forming anastomosis with the ductus venosus providing placental return
What is the fate of the anterior cardinal vein?
Right forms internal jugular and SVC, left forms left brachiocephalic trunk
They provide drainage from cranial territory.
What is the fate of the right posterior cardinal vein?
It becomes the proximal part of the azygous vein
What is the fate of the left umbilical vein?
It becomes the round ligament of the liver
What is the fate of the left posterior cardinal vein?
It becomes the left superior intercostal vein
