22. Great Vessels Embryology Flashcards
When does vasculogenesis begin?
By the end of the third week
What are the first to loci for the formation of blood islands?
Extraembryonic splanchnic mesoderm (around the yolk sac)
Aortic gonad mesonephric region (AGM)
What arises from aortic arch 1?
External carotid
Maxillary
What arises from aortic arch 2?
Stems of the stapedial arteries
What arises from the aortic sac?
Brachiocephalic artery
Base of the arch of the aorta
What arises from aortic arch 3?
Internal carotid
Common carotid
What arises from aortic arch 4?
Left: medial portion of the arch of the aorta
Right: proximal right subclavian (distal part comes from the 7th segmental artery, and another part comes from the dorsal aorta)
What arises from arch 6?
Pulmonary arteries
Left: Distal ductus arteriosus
Right: Distal portion degenerates
What arises from the 7th segmental artery?
Left: Entire left subclavian
Right: Distal part of the right subclavian (the proximal part came from arch 4, and another part comes from the dorsal aorta)
What arises from the dorsal aorta?
Right: Portion of the right subclavian (the proximal part comes from arch 4 and the distal part from 7th segmental artery)
Left: Descending aorta
What vessel brings oxygenated blood from the placenta to the newborn?
The left umbilical vein
What structure allows placental blood to bypass the fetal liver?
The ductus venosus
What do we call the neonatal remnant of the left umbilical vein?
The ligamentum teres (round ligament of the liver)
What is the embryological structure that becomes the ligamentum venosum?
Ductus venosus
What signaling molecule assists in the closure of the ductus arteriosus?
What signaling molecule can keep it open?
Bradykinin
Prostaglandins