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.
As your child develops and grows, they will grow and lose teeth. A baby's teeth start to come in around six months old and by age 3; most children have a full set of primary teeth. Baby teeth will be lost to make space for their adult (permanent) teeth, which begin to come in around age 6. The first molars usually appear between 9-11 years and a person usually has all of their adult teeth by age 21.