Cardiovascular Embryology 2 Flashcards
What are the two processes of vascular development?
Vasculaogenesis and angiogenesis
What is vasculogeneis?
Defined as new formation of a primitive vascular network
What is angiogenesis?
Defined as new growth of vessels from pre-existing blood vessels
What are the first arteries to appear in the embryo?
The left and right primitive aortae
The primitive aorta are split into what two parts?
Ventral and dorsal
The left and right primitive aortae fuse to form what?
The aortic sac
What form from the aortic sac?
Aortic branches
What occurs at the same time as the formation of aortic branches?
Pharyngeal arches develop during the 4th/5th week and each arch receives its own nerve and artery. These complexes are now called aortic arches
How many aortic arches initially form?
6
Where do all aortic arches terminate?
The dorsal aorta
What is the fate of the first and second aortic arches?
Maxillary arteries
What is the fate of the third aortic arch?
Common carotid and first part of internal carotid arteries
What is the fate of the fourth left aortic arch?
Distal aortic arch
What is derived from the right fourth aortic arch?
Proximal portion of the right subclavian vein
What is the deviated structure from the sixth aortic arch?
Left - left pulmonary artery and ductus anteriosus
Right - right pulmonary artery
What is the fate of the fifth aortic arch?
It totally regresses
What is the pathogenesis of most heart defects?
Regression of a tube that should stay or non-regression of a tube which shouldn’t stay
What four major pathologies are associated with abnormal cardioembryology?
- Aberrant subclavian vein
- Double aortic arch
- Patent ductus anteriosus (non closure of the ductus anteriosus)
- Coarctation of the aorta (pre- or post ductal)
What are the three fates of the vitelline arteries?
- Celiac artery - foregut
- Superior mesenteric artery - midgut
- Inferior mesenteric - artery of hindgut
What is the fate of the umbilical arteries?
Proximal portion persists to form internal iliac and superior vesical branches (to urinary bladder)
Distal portion degenerates and is obliterated to form medial umbilical ligaments
What is the function of the vitelline veins?
Carry blood from the yolk sac to the sinus venosus
What is the function of the umbilical veins?
Originate from chorionic villi of placenta - carrying oxygenated blood to the embryos
What is the function of the cardinal veins?
Draining the body of the embryo
What are the fates of the vitelline veins?
4 answers
- Portal veins
- Hepatocardiac inferior vena cava
- Liver sinusoids
- Superior mesenteric veins
What are the fates of the umbilical veins?
- Right and left umbilical veins
2. Ligamentum venosus
What is the fate of the cardinal veins?
Forms vena caval (SVC and IVC) by anastomosis
What are some pathologies associated with venous abnormalities?
Double IVC, Absence of IVC, Left SVC, and double SVC
Describe the development of the lymphatic system?
Develops at the end of the sixth week, forms six major lymph sac which are later joined by vessels
What three structures are important to consider during the foetuses transition from placental circulation to pulmonary circulation?
Ducti (venosus and arteriosus) - allows blood to bypass the liver and lungs through the oval foramen (foramen between atria)
What is the ductus venosus?
Vessel which transmits blood from the umbilical vein direct to the IVC, allowing them to bypass the liver
What physiological changes are associated with birth?
Foramen vale closes to form fossa ovalis
Ducti contract and become ligaments
