Normally, THREE major changes begin immediately after birth:
1. The ______ in the alveoli is ABSORBED into pulmonary LYMPHATICS and replaced by AIR. This provides oxygen.
2. The umbilical ARTERIES ________, and then the umbilical ARTERIES and VEIN are closed when the umbilical cord is CLAMPED. This removes the low-resistance placental circuit and results in an INCREASE in systemic BLOOD PRESSURE.
3. In response to alveolar distention with oxygen-containing gas and subsequent increased OXYGEN levels in the alveoli, blood VESSELS in the LUNG tissue RELAX, decreasing resistance to blood flow through the lungs.