Explanation:
Changes in the newborn at birth refer to the changes an infant's body undergoes to adapt to life outside the womb.
Lungs, Heart, and Blood Vessels

• The mother's placenta helps the baby "breathe" while it is growing in the womb.
• Oxygen and carbon dioxide flow through the blood in the placenta. Most of it goes to the heart and flows through the baby's body.
• At birth, the baby's lungs alveoli are filled with fluid. They are not inflated.
• The baby takes the first breath within about 10 seconds after delivery.
• This breath sounds like a gasp, as the newborn's central nervous system reacts to the sudden change in temperature and environment.

Once the baby takes the first breath, a number of changes occur in the infant's lungs and circulatory system:

• Increased oxygen in the lungs causes a decrease in blood flow resistance to the lungs.
• Blood flow resistance of the baby's blood vessels also increases.
• Fluid drains or is absorbed from the respiratory system.
• The lungs inflate and begin working on their own, moving oxygen into the bloodstream and removing carbon dioxide by breathing out (exhalation).