An expensive part of parenting is the clothes. Children outgrow clothing so fast that we keep having to get them new clothing. In the Toys section, we explore developmental aspects of skills. Now let us examine development of the skeletal system.
How does a person grow? The answer to this question requires knowing a bit of anatomy of how bones are structured. All bones begin with cartilage. In a process called ossification, the cartilage changes into bone matrix. This is a diagram of the process:
A baby’s skeleton begins as all cartilage, but most long bones begin ossification by week 8. As the baby develops inside of the womb, it’s bones grow (Marieb, Elaine N. and Hoehn, Katja, Human Anatomy and Physiology, 8th ed., San Francisco, Pearson Education Inc., 2010. Print). What started out as one tiny cell becomes a multi-trillion cell human being by birth. Pretty amazing! Fetal development can be seen in the following chart:
Even once a baby is born, not all of the bones are ossified. Some remain cartilage, the most well-known being the “soft spot”on the baby’s head, called the anterior fontanelle. The cranial (head) bones of a newborn baby are not completely fused; this allows the bones to move around safely during birth. When the doctor feels the top of your child’s head, the doctor is feeling for this soft spot. This is a diagram of the skull of a newborn:
If you re-examine the first diagram, you will notice that in the long bones there are spots called epiphyseal plates. This is how a bone elongates. This is how it happens:
When a baby is born, its head is very large in comparison to the rest of the body. However, as the baby develops and gets older, the proportion of its head to the rest of its body becomes much much smaller. Here is a diagram:
Here are growth charts, for boys and girls:
Here are charts for 0-36 months:
Speaking of child development, parents are always concerned that their child will need a shot at the next doctor’s visit. Here is a vaccine schedule, so you know more or less what you are dealing with:
As you can see, the baby does a lot of growing early on. This is why they constantly need new clothing.