| A | B |
|---|
| The body system that includes bones and teeth | skeletal system |
| A condition in which the child fails to grow at a healthy rate | Failure to thrive |
| The relative size of body parts | body proportions |
| Hardening of bones caused by the depositing of the minerals calcium and phosphorus | ossification |
| The first set of teeth | deciduous teeth |
| The use and control of muscles that direct body movements | motor development |
| Abilities to control and use large muscles | gross motor skills |
| Abilities to control and use small muscles | fine motor skills |
| A range of ages at which most children reach developmental milestones | age norm |
| Moving by pulling with the arms but not lifting the abdomen | crawling |
| Moving by pulling with the arms, using the hands and knees or hands and feet, and lifting the abdomen | creeping |
| Walking by holding onto an object or person | cruising |
| Movements, such as grasping, that are learned and controlled at will | voluntary |
