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.
The first baby teeth (also known as primary teeth) to come in are usually the lower central incisors around the age of six months. The last baby teeth to show up are the upper second primary molars, and they appear between 30 and 36 months of age. There are normally 20 baby teeth by the time a child reaches age 3.These primary teeth then remain unchanged for about three years. Not much happens to the baby teeth between 3 and 6 years of age. Between 6 and 8 years however, there is a flurry of activity as kids normally lose eight primary teeth in rapid succession.here are normally 20 baby teeth by the time a child reaches age 3. These primary teeth then remain unchanged for about three years. Not much happens to the baby teeth between 3 and 6 years of age.