The following are health and medical definitions of terms that appear in the Lung Cancer article. Abdomen: The belly, that part of the body that contains all of the structures between the... See the entire definition of Abdomen. Abdominal: Relating to the abdomen, the belly, that part of the body that contains all of ...
Head and neck muscles are the first to come under a baby's control. Muscle control moves downward, toward the feet. Babies typically roll from tummy to back first beginning at around 4 months of age and then back to tummy around 6 months of age, according to the A.I. DuPont Hospital for Children.
Generally by around three months old laughter should be quite common for most babies and by four months, a baby should be laughing out loud, chortling, giggling and squealing but, as in everything, babies develop at their own rate and there is nothing to worry about if your baby is slower to develop than others.