World of the Body:
fontanelle
A soft place in the scalp over a gap between four bones of the skull (the frontal and parietal bones on each side) which is normally present in the newborn infant. It gradually closes during the first 12-18 months of life, as bone formation extends until the edges come together at the sutures. The fontanelle reveals changes in pressure inside the skull: it tends to bulge when the baby cries, and to become sunken in a state of dehydration. The pulsations of the underlying brain with the heart beat can be felt at this site through the scalp.
— Stuart Judge
See skull.
