Human Growth and Development

Prepared by: Bio, A.; Cenizal, R.; Dela Cruz, M.A.; Dogelio, R.; Eugenio A.P

When the Morrisons were expecting their second child, the couple faced an anguishing dilemma.

Their first child, a girl born in 2002, had a condition known as congential adrenal hyperplasia, or CAH, which can sometimes result in male-like genitals in female newborns. So when Mrs. Morrison became pregnant again, the couple was well-aware the baby had a 1-in-8 chance of being born with the same disorder.

There were choices. They could treat the fetus with a powerful steroid that would most likely avert the possibility of the genitals becoming malformed. But the coupleworried about doing this. There was little research on the long-term effects of treating afetus with steroids, and statistically, there was a much greater chance that the babywouldn’t have the genital problem at all . . . .

The couple decided to forgo the steroid treatment. “It was touch-and-go, but in the end I couldn’t expose the baby to the drugs,” says Mrs. Morrison. When the baby arrived, it was a girl and, like her older sister, was born with swollen genitalia.

The Earliest Development & Significant Weeks of the Child• When an egg becomes fertilized by the sperm, the resulting

one-celled entity, called a zygote, immediately begins to develop.

The Earliest Development & Significant Weeks of the Child

Germination Period first 2 weeks of the zygote

Embryonic Period 2 weeks after the mother’s conception

The Earliest Development & Significant Weeks of the Child

• Fetal Period Week 8 until birth

• Week 16 until Week 18

Week 22

The Earliest Development & Significant Weeks of the Child

Week 24

The Earliest Development & Significant Weeks of the Child

Week 28

The Earliest Development & Significant Weeks of the Child

The Earliest Development & Significant Weeks of the Child

Sensitive PeriodWeek 38

Genetic Influences on the Fetus

The process of fetal growth that we have just described reflects normal development, which occurs in 95–98% of all pregnancies. Some individuals are less fortunate; in the remaining 2–5% of cases, children are born with serious birth defects. A major cause of such defects is faulty genes or chromosomes.

Phenylketonuria (PKU)

A child born with the inherited disease phenylketonuria cannot produce an enzyme that is required for normal development.

Sickle-cell anemia

Abnormal shaped RBCs

Sickle-Cell Anemia Patients

Tay-Sachs Disease

Children born with these disease usually die at age 3 or 4 because of their inability to break down fats in their body.

Down Syndrome

Occurs when the zygote receives an extra chromosome at the moment of conception.

Down Syndrome Patients

Pre-natal Environmental Influences

Genetic factors are not the only causes of difficulties in fetal development. Environmental influences—the nurture part of the nature–nurture equation—also affect the fetus. Some of the more profound consequences are brought about by teratogens, environmental agents such as a drug, chemical, virus, or other factor that produce a birth defect.

Mother’s Nutrition What a mother eats during her pregnancy can have

important implications for the health of her baby. Seriously undernourished mothers cannot provide adequate nutrition to a growing fetus, and they are likely to give birth to underweight babies.

FACTORS:

Mother’s Illness Several diseases that have a relatively minor effect

on the health of a mother can have devastating consequences for a developing fetus if they are contracted during the early part of a pregnancy.

• Mother’s Emotional State• Mothers who are anxious and tense during the last months of

their pregnancies are more apt to have irritable infants who sleep and eat poorly.

FACTORS:

• Mother’s Use of Drugs• Mothers who take illegal, physically addictive drugs such as

cocaine run the risk of giving birth to babies who are similarly addicted.

Factors:

AlcoholAlcohol is extremely dangerous to fetal

development. For example, 1 out of every 750 infants is born with fetal alcohol syndrome ( FAS ).

Nicotine Use Pregnant mothers who smoke put their children

at considerable risk. Smoking while pregnant can lead to miscarriage and infant death.

The Extraordinary Newborn

His head was molded into a long melon shape and came to a point at the back . . . . He was covered with a thick greasy white material known as “vernix,” which made him slippery to hold and also allowed him to slip easily through the birth canal. In addition to a shock of black hair on his head, his body was covered with dark, fine hair known as “lanugo.” His ears, his back, his shoulders, and even his cheeks were furry . . . . His skin was wrinkled and quite loose, ready to scale in creased places such as his feet and hands . . . . His ears were pressed to his head in unusual positions—one ear was matted firmly forward on his cheek. His nose was flattened and pushed to one side by the squeeze as he came through the pelvis.

The Extraordinary Newborn

The Extraordinary Newborn

• Several factors cause a neonate’s strange appearance. The trip through the mother’s birth canal may have squeezed the incompletely formed bones of the skull together and squashed the nose into the head. The skin secretes vernix, a white greasy covering, for protection before birth, and the baby may have lanugo, a soft fuzz, over the entire body for a similar purpose. The infant’s eyelids may be puffy with an accumulation of fluids because of the upside-down position during birth. All these features change during the first two weeks of life as the neonate takes on a more familiar appearance. Even more impressive are the capabilities a neonate begins to display from the moment of birth—capabilities that grow at an astounding rate over the ensuing months.

REFLEXES A neonate is born with a

number of reflexes. Critical for survival, many of those reflexes unfold naturally as part of an infant’s ongoing maturation.

REFLEXES

Rooting Reflex

Sucking Reflex

Gag Reflex

Startle Reflex

OBabinski Reflex

Development of the Senses: Taking in the World

When proud parents peer into the eyes of their neonate, is the child able to return their gaze? Although it was thought for some time that newborns can see only a hazy blur, most current findings indicate that neonates’ capabilities are far more impressive. Although their eyes have a limited capacity to focus on objects that are not within a seven- to eight-inch distance from the face, neonates can follow objects moving within their field of vision. They also show the rudiments of depth perception as they react by raising their hands when an object appears to be moving rapidly toward the face.

Habituation the decrease in the response to a

stimulus that occurs after repeated presentations of the same stimulus.

Significant Periods for the Child Second Day

Third Day

First Month

Fourth-Fifth Month

Sixth Month

Seventh Month

Twelfth Month

Infancy Through Childhood• Physical Development

• Children’s physical growth is the most obvious sign of development. During the first year of life, children typically triple their birth weight and their height increases by about half. This rapid growth slows down as the child gets older.

• Social Development• As anyone who has seen infants smiling at the sight of

their mothers can guess, at the same time that infants grow physically and hone their perceptual abilities, they also develop socially. The nature of a child’s early social development provides the foundation for social relationships that will last a lifetime.

▫As the age progresses, the size of the head decreases until the individual reaches adulthood.

SOCIAL DEVELOPMENT

Attachment positive emotional bond between a child and a particular individual

Understanding Attachment …

Understanding Attachment …

FATHER’S ROLE

Although early developmental research focused largely on the mother-child relationship, more recent research has highlighted the father’s role in parenting—and with good reason: The number of fathers who are primary caregivers for their children has grown significantly, and fathers play an increasingly important role in their children’s lives. For example, in almost 13% of families with children, the father is the parent who stays at home to care for preschoolers.

When fathers interact with their children, their play often differs from mothers’ play. Fathers engage in more physical, rough-and-tumble sorts of activities, whereas mothers play more verbal and traditional games, such as peekaboo. Despite such behavioral differences, the nature of attachment between fathers and children compared with that between mothers and children can be similar. In fact, children can form multiple attachments simultaneously

Social Relationship With Peers• By the time they are 2 years old, children become less

dependent on their parents, more self-reliant, and increasingly prefer to play with friends. Initially, play is relatively independent.

• As children reach school age, their social interactions begin to follow set patterns and become more frequent. They may engage in elaborate games involving teams and rigid rules. This play serves purposes other than mere enjoyment. It allows children to become increasingly competent in their social interactions with others. Through play they learn to take the perspective of other people and to infer others’ thoughts and feelings, even when those thoughts and feelings are not directly expressed

Consequences of Child Care Outside the Home

• Do child-care arrangements outside the home benefit children’s development?

Authoritarian Parents

Parenting Styles & Social Development

Permissive Parents

Uninvolved Parents

Theories of Development

•Erickson’s Theory of Psychosocial Development

▫Psychosocial Development▫Trust-Versus-Mistrust Stage▫Autonomy-Versus-Shame-and-Doubt Stage

▫Initiative-Versus-Guilt Stage▫Industry-Versus-Inferiority Stage