The 2 carotid arteries on each side of the neck are the most important because they supply blood to the parts of the brain that are involved in thinking, movement, sensation and speech. The other 2 arteries that bring blood to the brain, called the vertebral arteries, supply the brainstem.
The vast majority of babies sprout their first tooth when they're between 4 and 7 months old. An early developer may get his first white cap as early as 3 months, while a late bloomer may have to wait until he's a year old or more.y age 3, your child should have a full set of 20 baby teeth, and they shouldn't start to fall out until his permanent teeth are ready to start coming in â around age 6.
Baby teeth are also called primary or milk teeth. They have very thin roots that look like thread. Your baby will start to get teeth somewhere around six months of age, but the first tooth can appear anytime between three and twelve months of age. Your child should have all 20 baby teeth by around age three â 10 on the bottom and 10 on the top.