By the end of this week your baby’s lungs will have developed alveoli, tiny, capillary-rich sacs in the lungs where the exchange of oxygen and carbon dioxide takes place. Your baby’s nostrils will even be open, although he still would need help breathing if he were to be born preterm.

The baby’s brain activity is increasing every day, and although you may ask yourself what images could your baby possibly have in his little head now, tests show that babies move their eyes a lot under their eyelids when sleeping, as newborns do. Experts consider this to be proof that the baby is dreaming when he sleeps. To back up this theory, tests have determined that the areas of vision and the ears in the brain show activity that indicates that they already register sensations.