Human Development: Conception Through Young Adult

Stages of Prenatal Development

Human development begins at conception and progresses through distinct prenatal stages, each characterized by specific physiological changes and vulnerabilities.

• Pre-embryonic Stage: Conception to 3rd week. Formation of three cell layers: endoderm, mesoderm, and ectoderm.

• Embryonic Stage: 4th to 8th week. All basic organs are established; rapid growth and differentiation occur. This is the stage most vulnerable to congenital anomalies due to environmental factors (e.g., alcohol, tobacco, drugs).

• Fetal Stage: 9th week to birth. Body organs and systems continue to grow and mature.

Example: Exposure to teratogens during the embryonic stage can result in birth defects.

Physical Characteristics of the Neonate (Birth to 28 Days)

The neonate exhibits unique physical and physiological traits essential for adaptation to life outside the womb.

• Reflexes: Moro, stepping, grasp, hand-to-mouth, sucking, swallowing, blinking, sneezing, yawning.

• Temperature Regulation: Body temperature responds quickly to environmental changes.

• Sensory Response: Uses senses to interact with environment.

• Elimination: Stool and urine are eliminated.

• Behavioral States: Active crying and quiet alertness.

Health of the Neonate

Neonates possess inherited immunity and face specific health challenges.

• Immunity: Maternal immunoglobulins cross the placenta; breastfeeding provides additional immunity (recommended exclusively for first 6 months).

• Health Risks: Birth difficulties, congenital abnormalities, respiratory distress (especially in premature or cesarean-delivered neonates).

Physiologic Development of the Infant (1 Month to 1 Year)

Infants undergo rapid growth and development in their first year.

• Brain: Grows to half adult size.

• Temperature: Stabilizes.

• Motor Skills: Develop; eyes begin to focus.

• Heart: Doubles in weight; heart rate slows; blood pressure rises.

• Teeth: Deciduous teeth erupt at 4–6 months.

• Weight: Birth weight triples by 1 year (average 22 lb).

Psychosocial Development of Infant

Infants develop trust and begin to meet key developmental tasks.

• Freud: Oral stage – immediate gratification of needs.

• Erikson: Trust vs. mistrust – development of trust.

• Havighurst: Tasks include taking food, walking, talking.

Special Considerations for the Infant

Infant health and development are influenced by attachment, temperament, and risk factors.

• Attachment and Bonding: Bonding occurs in the first hours after birth and is necessary for later attachment.

• Play: Essential for development.

• Temperament: Easy, slow to warm, difficult.

• Health Risks: Colic, failure to thrive, accidental injuries, SIDS, child maltreatment.

Role of the Nurse in Infancy

Nurses play a critical role in promoting infant health and safety.

• Teaching: Educating family members and caregivers is the most essential role.

• Health Promotion: Safety, nutrition, hygiene, growth and development, immunizations.

Physiologic Development of Toddler (1 to 3 Years)

Toddlers experience rapid physical and motor development.

• Brain: Rapid growth.

• Motor Skills: Walks, runs, kicks, climbs, rides tricycle; uses fingers for small objects; drinks from cup, uses spoon.

• Weight: Four times birth weight.

• Bladder Control: Daytime control, sometimes at night.

• Fine Motor: Turns pages, draws stick people by age 3.

Cognitive Development of Toddler

Toddlers begin to understand object permanence and develop language skills.

• Piaget: Last two stages of sensorimotor development.

• Object Permanence: Begins to understand.

• Language: Short sentences by age 2.

• Self-Concept: Understands self as separate from others; begins perception of body image and sex identity.

Psychosocial Development of Toddler

Toddlers develop autonomy and begin to distinguish right from wrong.

• Freud: Anal stage – focus on toilet training.

• Erikson: Autonomy vs. shame and doubt.

• Behaviors: Negativism, regression, separation anxiety.

• Havighurst: Tasks include controlling elimination, learning sex differences, forming concepts, learning language, distinguishing right from wrong.

Nurse’s Role: Health of the Toddler

Accidents are the highest risk; nurses promote health primarily through teaching.

• Encourage Independence: Set firm limits.

• Health Promotion: Safety, nutrition, hygiene, elimination, growth and development.

Physiologic Development of Preschooler (3 to 6 Years)

Preschoolers develop increased coordination and motor skills.

• Head: Near adult size by age 6.

• Body: Leaner, more coordinated.

• Motor Skills: Jumping, skipping, throwing, printing letters/numbers.

• Teeth: Full set of 20 deciduous teeth.

• Weight: Average 45 lb.

Cognitive Development of Preschooler

Preschoolers develop socialization and reasoning abilities.

• Egocentrism: Decreases as socialization increases.

• Play: More related to real-life events.

• Curiosity: Constant questions, improved reasoning.

• Language: More elaborate.

Psychosocial Development of Preschooler

Preschoolers develop conscience and begin to distinguish right from wrong.

• Freud: Phallic stage – focus on genitals.

• Erikson: Initiative vs. guilt – conscience develops.

• Havighurst: Tasks include learning sex differences/modesty, describing reality, preparing to read, distinguishing right from wrong.

• Kohlberg: Preconventional phase – behavior dominated by obeying rules to avoid punishment or receive reward.

Role of the Nurse: Health of the Preschooler

Nurses identify children at risk for obesity and teach families about health and wellness.

• Communication: Explain procedures in child-friendly language.

• Emotional Support: Encourage expression of feelings.

• Caregiver Involvement: Encourage active participation.

Physiologic Development of School-Aged Child (6 to 12 Years)

School-aged children experience steady growth and maturation of motor and cognitive abilities.

• Brain: 90–95% adult size; nervous system nearly mature by age 12.

• Motor Skills: Writing in script and sentences by age 12.

• Digital Natives: Use technology with minimal supervision.

• Sexual Organs: Grow but dormant until late in period.

• Teeth: All permanent teeth except 2nd/3rd molars by age 12.

• Growth: Height increases 2–3 inches/year; weight increases 3–6 lb/year.

Cognitive Development of School-Aged Child

Children develop logical thinking and problem-solving skills.

• Piaget: Concrete operational stage – organizes facts, solves problems.

• Inductive Reasoning: Used to solve new problems.

• Measurement: Concepts develop.

• Classification: Systems develop.

• Empathy: Awareness of others' feelings.

• Language: Well-developed skills.

Psychosocial Development of School-Aged Child

Children develop self-identity and morality.

• Freud: Latency stage – strong identification with own sex.

• Erikson: Industry vs. inferiority – focus on learning useful skills.

• Havighurst: Tasks include learning games, social roles, writing, reading, independence, conscience, morality, values.

• Moral Development: Conventional phase.

• Spiritual Development: Fowler's theory.

Health Issues for School-Aged Children

School-aged children face a range of health challenges.

• Obesity

• Accidents

• Communicable Conditions

• Attention Deficit Hyperactivity Disorder (ADHD)

• Seizure Disorders

• Hypertension

• Type 1 Diabetes Mellitus

• Scoliosis

• Learning Disabilities

• Chronic Illnesses

• Enuresis

Role of the Nurse: Health of School-Aged Children

Nurses provide education and support for health promotion and illness prevention.

• Teaching: Individual and family education.

• Physical Activity: Encourage and prevent obesity.

• School Violence: Recognize and address bullying.

• Hospitalization: Allow some control to reduce stress.

• Health Promotion: Safety, nutrition, hygiene, sexual development, growth and development.

Physiologic Development of the Adolescent

Adolescents undergo rapid physical changes and sexual maturation.

• Growth: Feet, hands, long bones grow rapidly; muscle mass increases.

• Puberty: Begins at 9–13 years (girls), 10–14 years (boys).

• Glands: Sebaceous and sweat glands become active.

• Adult Size: Usually reached.

Three Stages of Puberty

• Prepubescence: Secondary sex characteristics begin; reproductive organs not functional; downy pubic hair appears.

• Pubescence: Secondary sex characteristics continue; ova and sperm produced.

• Postpubescence: Reproductive function and secondary sex characteristics reach adult maturity.

Cognitive Development of Adolescent

Adolescents develop advanced reasoning and abstract thinking.

• Piaget: Formal operations – deductive, reflective, hypothetical reasoning.

• Long-Term Goals: Can be set.

• Time and Future: Concepts become real.

• Egocentrism: Returns; imaginary audiences and daydreaming common.

Cognitive Development of Young Adult

Young adults demonstrate increased creativity, objectivity, and realism.

• Learning: Enhanced through education and life experiences.

• Self-Centeredness: Less than in adolescence.

Psychosocial Development of Adolescent/Young Adult

Adolescents and young adults develop identity, values, and independence.

• Freud: Genital stage – full sexual function.

• Erikson: Identity vs. role confusion – self-concept stabilized; peer group influence.

• Havighurst: Develop masculine/feminine roles, values, ethical system.

• Levinson: Early adult transition – career choices, relationships, values, lifestyle.

• Gould: Theory of transformation – establish adult control, separate from family.

Special Considerations for the Young Adult

Young adults face decisions about career, family, and moral development.

• Career: Choosing occupation.

• Family: Establishing family.

• Moral Development: Conventional level; value conformity, loyalty, social order; may enter postconventional stage.

• Spiritual Development: Fowler's individuating-reflective period.

Health Issues for Adolescents/Young Adults

Adolescents and young adults are at risk for various health problems.

• Injuries

• Substance Use, Misuse, and Abuse

• Suicide

• Pregnancy

• Nutritional Problems

• Sexually Transmitted Infections (STIs)

• Developmental and Situational Stressors

Developmental and Situational Stressors: Adolescent and Young Adult

Stressors can impact health and well-being during adolescence and young adulthood.

• Sexual Orientation: Related stressors.

• Peer Pressure

• Gender Identity

• Family Stressors

• Pressures to Marry

• Desire for Love and Belonging

• Financial Pressures

• Divorce and Separation

Role of the Nurse: Health of Adolescents and Young Adults

Nurses assess reproductive changes, facilitate healthy relationships, and provide educational and recreational support.

• Assessment: Changes in reproductive functioning.

• Family Relationships: Facilitate healthy interactions.

• Support: Educational and recreational activities to reduce isolation when ill or hospitalized.

Summary Table: Stages of Development and Key Features

Additional info: The notes expand on brief points with academic context, including developmental theories (Freud, Erikson, Piaget, Havighurst, Kohlberg, Fowler, Levinson, Gould), and highlight the nurse's role in health promotion and prevention across stages. Health issues relevant to personal health (e.g., obesity, substance use, STIs, chronic illness) are included for exam preparation.