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.
A child gets two sets of teeth. The first set, baby teeth, starts to grow when the child is a baby. The second and last set grows in at school age. They are the permanent teeth. Permanent teeth should last a lifetime.A child grows his first baby tooth at about 7 months of age.It is usually a front one.he remaining baby teeth grow in over the next 24 months. By the time the child is 30 months old, there will be a total of 20 baby teeth in his mouth, 10 on top and 10 on the bottom. Most permanent teeth form under the baby teeth.