1. Infants – Physical Development
Child & Human Development
Unit 2: Infants
Ages: Birth to Age 1

2. Skeletal Growth
Skeletal System is made of bones and teeth. Skeletal growth refers to the changes in length, weight and the appearance of teeth.
Average Length: 20 to 21 inches
Most infants reach 1 ½ times their birth lengths (adding 9 to 10 inches) during the first year.

3. Weight
Babies usually double their birth weights in four or five months and triple their birth weights by one year.

4. So…
If a baby’s beginning weight is 8 pounds, they will weigh approximately______lbs. at 4-5 months and _______lbs. at age 1!!! 16 24

5. By about 9 months, the infant becomes chubbier
By about 9 months, the infant becomes chubbier. This change happens because fat tissues under the skin have increased.

6. After this time, fat tissues begin to decrease
After this time, fat tissues begin to decrease. Even at this age – boys have more muscle length and thickness, while girls have more fat.

7. Average Length and Weight
During First Year
Age in Months
Length in Inches
Weight in Pounds
Birth 20
7 ½ 3
23 ¾
12 ½ 6 26
16 ¾ 9 28 12
29 ½
22 ¼

8. What happens if a baby doesn’t grow at a similar rate?

9. Failure to Thrive Rates of growth slow considerably over time.
This may indicate that a health problem exists.

10. Causes of Failure to Thrive
Diseases that prevent all or some nutrients from being absorbed or that cause nutrients to be quickly expelled from the body.
The baby’s food is not providing enough nutrients (diluted formula or breast milk affected by mother’s malnutrition)
Nutrients needed for bone development: Calcium, vitamin d, phosphorus, protein, etc.

11. Causes of Failure to Thrive
Feedings are offered too infrequently or last too short a time.
The baby is abused or neglected

12. Body Proportions Infants do not look like small adults.
Head makes up ¼ of his or her total length
1/10

13. Bones and Teeth Infant skeleton is mostly made up of cartilage.
Infants bones do not break easily
Skeletons are not sturdy = no sitting and standing
Because of softness, bones can easily misshapen.
Lying flat in one position all the time can flatten a baby’s head in one place.

15. More common because of the recommendation for babies to sleep on their backs (Prevents SIDS)
Changing a baby’s position during waking hours can prevent their heads from flattening.
Many doctors now recommend “tummy time” once babies can hold their heads up while alert. (two-four months)

16. “Tummy Time” Encourages development of motor skills such as:
Rolling over
Reaching
Crawling

17. Bones = Changes occur in 3 Stages during 1st Year!
Length of bones increases
Ossification begins (hardening of bones)
Number of bones changes
Hand and Wrist = 1 y.o = 3 bones
Hand and Wrist = adult = 28 bones

18. Teeth!
By birth, all deciduous teeth (nonpermanent) teeth and a few permanent teeth are developing deep in the jaw
Hand out Sheet

19. What's happening?

20. Most babies begin cutting teeth during the second half of the first year. (6-12 months)

21. Motor Development
The use and control of muscles that direct body movements.

22. Motor Development Gross-Motor Skills
Learning to use and control large muscles helps babies learn to crawl and walk.
Trunk
Arms
Legs
Gross-Motor Skills

23. Motor Development Fine Motor Skills
Being able to control small muscles
Hands
Fingers
Fine Motor Skills

24. Gross Motor Skills

25. Fine Motor Skills
Gross Motor Skills