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.
Most babies get their first tooth at around 6 months, but your child's chompers may appear as early as 3 months or as late as 14, depending on such factors as when Mom and Dad started sprouting teeth and whether or not your baby was a preemie (preemies tend to teethe on the late side).ypically, babies get their teeth in pairs. First come the middle two on the bottom. A month or so later, the two above those arrive. Still, it's not uncommon to see a baby with four bottom and no upper teeth, or the reverse.