1 Physical Growth and Development
Discuss physical growth and development in
in Infancy
nfancy.
Patterns of Growth
Nutrition
Height and Weight
Sleep
The Brain
Infants' physical development in the first two years of life is extensive. Newborns' heads are
quite large in comparison with the rest of their bodies. They have little strength in their nec
and hold their heads up, but they have some basic reflexes. In the span of 12 months,
infants become capable of sitting anywhere, standing, stooping, climbing, and usually walk
During the second year, growth decelerates, but rapid increases in such activities
as
running and climbing take place. Let's now examine in greater detail the sequence of physi
cal development in infancy.
PATTERNS OF GROWTH
An extraordinary proportion of the total body is occupied by the head during prenatal deve
A baby is the most
and early (see Figure 4.1). The cephalocaudal pattern is the sequence in
which the growth always occurs at the top the head-with physical growth a
complicated object made by
of features gradually working their way down from top to bottom (for example,
shoulders, middle and on). same pattern occurs in the head area, because the
unskilled labor.
of the head-the eyes and brain-grow faster than the lower parts, such as the ANONYMOUS
Motor development generally proceeds according to the dal principle. For
example, objects before they can control their torso, and they can use their hand
infants see ong before they can crawl or walk. However, development does not follow a rigid blueprint.
One study found that infants reached for toys with their feet prior to with their hands
(Galloway & Thelen, 2004). On average, infants first touched the their feet when
they were 12 weeks old and with their hands when they were 16 weeks old.
Growth also follows the proximodistal pattern, the sequence in which growth starts at
the center of the body and moves toward the extremities. For example, infants control the
muscles of their trunk and arms before they control their hands and fingers
and they use their
whole hands before they can control several fingers.
cephalocaudal pattern Developmental sequence
in which the earliest growth always occurs at the
HEIGHT AND WEIGHT
top-the head-with physical growth in size,
weight, and feature differentiation gradually
The average North American newborn is 20 inches long and weighs 7 pounds. Ninety-five
working from top to bottom.
percent of full-term newborns are 18 to 22 inches long and weigh between 5 and 10 pounds.
In the first several days of life, most newborns lose to 7 percent of their body weight
proximodistal pattern Developmental sequence
in which growth starts at the center of the body
before they adjust to feeding by sucking, swallowing, and digesting. Then they grow rapidly,
and moves toward the extremities.
n Infancy
CHAPTER 4
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