Major events
Whilst physical development and maturation occurs in all body systems and body regions, there are some that are very notable in this age range. These include developments associated with the eyes, mouth, neck and torso.
Teeth: By 2 years old, the child will have around 16 primary teeth that have erupted. The remaining primary molar teeth continue to erupt until at around 2½ years old, the child will have a full set of primary teeth.
Chest: The alveoli within the lungs that started development before birth are still maturing. This will finally be complete around the age of 8 years old.
Eyes: Vision is typically good, although some children can still have problems tracking a moving object and being able to judge how fast it is going.
Teeth: By 2 years old, the child will have around 16 primary teeth that have erupted. The remaining primary molar teeth continue to erupt until at around 2½ years old, the child will have a full set of primary teeth.
Chest: The chest and lungs are still developing. The child’s horizontal ribs gradually change to being more rounded. The lungs are still developing the alveoli that started being made just before birth occurred. The development of alveoli will finally stop within the following phase around the age of 8 years old.
Eyes: Vision is typically good, although some children can still have problems tracking a moving object and being able to judge how fast it is going.
Neck: The neck also starts to emerge around 3 years old and as this happens the trachea lengthens. This lengthening impacts on the strength of the voice.