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.
Teething. The time when teething begins varies widely. Most babies are 4 to 7 months old when the first tooth appears, according to the American Academy of Pediatrics. Some little ones may have to wait until they reach 15 months of age. Watch your baby's lower gum when you suspect he is teething.His first tooth will most likely be one of the bottom front teeth.ost babies are 4 to 7 months old when the first tooth appears, according to the American Academy of Pediatrics. Some little ones may have to wait until they reach 15 months of age. Watch your baby's lower gum when you suspect he is teething.