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.
Starting at around 3 months of age, infants begin to show outward signs that baby teeth are coming. They produce more saliva and will put their fingers in their mouths. This drooling can go on for several weeks before you'll see a tooth. Infants typically get their first tooth between ages 5 and 12 months. The bottom incisors emerge first, followed by the top incisors. Usually around 2 years of age, a toddler has a full set of teeth, explains Dr. Edward Kulich of New York, NY.