Infants Physical Development Child Human Development Unit 2

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

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.

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

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

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

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

Average Length and Weight During First Year Age in Months Length in Inches Weight in Pounds Birth 20 7½ 3 23 ¾ 12 ½ 6 26 16 ¾ 9 28 20 12 29 ½ 22 ¼

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

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

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.

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

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

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.

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)

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

Bones = Changes occur in 3 Stages during 1 st Year! 1. Length of bones increases 2. Ossification begins (hardening of bones) 3. Number of bones changes • • Hand Wrist = 1 y. o = 3 bones Hand Wrist = adult = 28 bones

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

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

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

Motor Development • Learning to use and control large muscles helps babies learn to crawl and walk. – Trunk – Arms – Legs

Motor Development • Being able to control small muscles – Hands – Fingers

Gross Motor Skills

Fine Motor Skills Gross Motor Skills