Intra- and Extraembryonic Arteries and Veins

• The tree circulation systems:

  • embryonic
  • vitelline
  • placental
• Embryonic consists of two groups of arteries and veins
• Embryonic:

  Starting from the outflow end of the heart, blood enters the ventral aorta (ventral aortic root), which splits into a series of aortic arches that pass the pharyngeal pouch. Blood then enters into paired dorsal aorta that distributes blood throughout the body. A system of cardinal veins collects the blood.
• Embryonic:

  The paired anterior cardinal veins (vena cardinalis anterior) collects blood from the cephalic end of the embryo. The posterior cardinal veins (vena cardinalis posterior) collects blood from the caudal end of the embryo. Blood returns to the heart via a common inflow tract called the common cardinal vein (vena cardinalis communis).
• The vitelline circulation is an extraembryonic circulatory loop that supplies the yolk sac
• A vitelline vein drains the yolk sac, a vitelline artery directs blood to the yolk and is attached to the dorsal aorta in the gastrointestinal region.
• The placental circulation also is an extraembryonic circulatory loop
• placental circulation consist of the umbilical artery and veins
• The left and right umbilical arteries (arteria umbilicalis) carry blood from the embryo to the placenta
• The umbilical vein carries oxygenated blood from the placenta to the embryo.
• The extraembryonic vitelline and placental circulations do not persist after birth
• Nutrient and oxygen supply: rich or poor

  A) Rich

  B) Poor

  C) Rich

  D) Rich

  E) Poor

  F) Poor