Ch3 Physical development and biological aging

What do these concepts mean regarding body growth and change: cephalocaudal and proximodistal patterns?

Cephalocaudal is when the growth of the infant starts at top (neck, shoulders, etc) and goes down whereas proximodistal is when the growth of the body begins in the center of the body

Childhood

During early childhood, the brain and head grow more rapidly than any other part of the body. Researchers have found that dramatic anatomical changes in brain patterns occur from 3 to 15 years of age, often involving spurts of brain activity and growth.

In which stage of development do we peak regarding strength and body tone?

Early adulthood. Late teens, early twenties

Which two groups of girls and boys in puberty present the highest risks, how do they become at risk, and why?

Early maturing girls as they have more academic problems, lower self confidence, more psychological disorders, earlier experiences with alcohol, drugs, and sex. Late maturing boys anxious and self conscious, insecure, more likely to act in deviant behavior, get in trouble more and act out more.

How do females and males differ in sexual maturity?

Females sexually maturity is around 16 and they mature faster than boys. Males start at around age 12-13 and fully mature around 18

What are the four brain lobes, and what is the function for each one?

Frontal lobe- cognitive skills and emotions Temporal lobe- memory Occipital lobe- vision Parietal lobe- touch, taste, and temperature

What three factors can help explain weight variation?

Genetics: growth hormone, environment and nutrition

How do girls' and boys' weight differ in early childhood?

Girls are smaller and weigh less and they also have more fatty tissue while boys have more muscle

How is body image viewed differently between girls and boys?

Girls tend to be more negative when they view themselves. Girls are two years ahead and the culture we are in emphasizes more on the girls image

Height and weight in infancy and childhood

Height and weight increase rapidly in infancy and then take a slower course during childhood.

Centenarians

Heredity, family history, health, education, personality, and lifestyle are important factors in living to be a centenarian. The ability to cope with stress also is important.

What is most important regarding an adolescent timing during puberty?

How they perceive their adolescent timing

Patterns of growth

Human growth follows cephalocaudal (fastest growth occurs at the top) and proximodistal patterns (growth starts at the center of the body and moves toward the extremities).

Early adulthood

In early adulthood, height remains rather constant. Many individuals reach their peak of muscle tone and strength in their late teens and twenties; however, their physical capacity may decline during their thirties.

Late adulthood

In late adulthood, outwardly noticeable physical changes become more prominent, individuals get shorter, and weight often decreases because of muscle loss. The circulatory system declines further.

What risk do men over 45 y.o. have regarding producing offspring?

Increases the risk of autism

What does the term "climacteric" mean, and when does it occur?

Is the mid life transition and fertilization declines.

Life expectancy and life span

Life expectancy is the number of years an individual is expected to live when he or she is born. Life span is the maximum number of years any member of a species has been known to live. On average, females live about five years longer than males do. The sex difference is likely due to biological and social factors. An increasing number of individuals live to be 100 or older.

Adolescent and emerging adulthood sleep

Many adolescents stay up later and sleep longer in the morning than they did when they were children. Recent interest focuses on biological explanations of these developmental changes in sleep during adolescence and their link to school success. Recent research indicates that a majority of first-year college students have sleep difficulties and that they go to bed even later and get up later than adolescents do. However, by the end of college they have begun to reverse this trend.

Childhood sleep

Most experts recommend that young children get 11 to 13 hours of sleep each night. Most young children sleep through the night and have one daytime nap. Inadequate sleep is linked to children's depression and attention problems. Children can experience a number of sleep problems.

Infancy sleep

Newborns sleep about 16 to 17 hours a day. By about 4 months of age, most infants have sleep patterns similar to those of adults. REM sleep occurs more in infancy than in childhood and adulthood. A special concern is sudden infant death syndrome.

What four influences help explain hormonal changes in puberty in the 20th century?

Nutrition, medical advancements, hormones pesticides and herbicides

What are primary and secondary sex characteristics?

Primary is structures necessary for reproduction and secondary is pubic hair, under arm hair and breasts

Infancy

Researchers have found that early experience influences the brain's development. Myelination begins prenatally and continues after birth. In infancy, one of the most impressive changes in the brain is the enormous increase in dendrites and synapses. These connections between neurons are overproduced and pruned. Specialization of functioning does occur in the brain's hemispheres, as in language, but for the most part both hemispheres are at work in most complex functions.

neuroconstructivist view

This increasingly popular view of brain development states that biological processes and environmental conditions influence the brain's development; the brain has plasticity; and cognitive development is closely linked with brain development.

corpus callosum

a large bundle of axon fibers that connects the brain's left and right hemispheres, thickens in adolescence, and this thickening improves the adolescent's ability to process information.

prefrontal cortex

the highest level of the frontal lobes that are involved in reasoning, decision making, and self-control, continues to mature through emerging adulthood or later.

amygdala

the part of the limbic system that is the seat of emotions such as anger, matures earlier than the prefrontal cortex. The later development of the prefrontal cortex combined with the earlier maturity of the amygdala may explain the difficulty adolescents have in putting the brakes on their emotional intensity.

Middle adulthood

-In middle adulthood, changes usually are gradual. Visible signs of aging, such as the wrinkling of skin, appear in the forties and fifties. Middle-aged individuals also tend to lose height and gain weight. Strength, joints, and bones show declines in middle age. The cardiovascular system declines in functioning, and lung capacity begins to decline, more so in smokers than nonsmokers. -The climacteric is a term used to describe the midlife transition in which fertility declines. Menopause is the time in middle age, usually in the late forties or early fifties, when a woman has not had a menstrual period for a year. Men do not experience an inability to father children in middle age, although their testosterone level declines.

Adulthood and aging

-On average, the brain loses 5 to 10 percent of its weight between the ages of 20 and 90. Brain volume also decreases with aging. Shrinking occurs in some areas of the brain, such as the prefrontal cortex, more than in other areas. -A general slowing of function of the central nervous system begins in middle adulthood and increases in late adulthood. A decline in the production of some neurotransmitters is related to aging. -Neurogenesis has been demonstrated in lower mammals, but whether it occurs in human adults is still controversial. It appears that dendritic growth can occur in adults. The brain has the capacity to virtually rewire itself to compensate for loss in late adulthood. Brain lateralization usually decreases in older adults.

Puberty

-Puberty is a brain-neuroendocrine process occurring primarily in early adolescence that provides stimulation for the rapid physical changes that accompany this period of development. -A number of changes occur in sexual maturation. The growth spurt involves rapid increases in height and weight and occurs about two years earlier for girls than for boys. -Extensive hormonal changes characterize puberty. Puberty began occurring much earlier in the twentieth century mainly because of improved health and nutrition. The basic genetic program for puberty is wired into the nature of the species, but nutrition, health, and other environmental factors affect the timing of puberty. -Adolescents show heightened interest in their bodies and body images. Younger adolescents are more preoccupied with these images than older adolescents. -Adolescent girls often have a more negative body image than do adolescent boys. -Early maturation often favors boys, at least during early adolescence, but as adults, late-maturing boys have a more positive identity than do early-maturing boys. Early-maturing girls are at risk for a number of developmental problems.

Brain physiology

-The brain has two hemispheres, each of which has four lobes (frontal, occipital, temporal, and parietal). -Throughout the brain, nerve cells called neurons process information. Communication among neurons involves the axon, dendrites, synapses, neurotransmitters, and the myelin sheath. Clusters of neurons, known as neural circuits, work together to handle specific types of information.

Biological theories of aging

-The evolutionary theory of aging proposes that natural selection has not eliminated many harmful conditions and nonadaptive characteristics in older adults; thus, the benefits conferred by evolution decline with age because natural selection is linked to reproductive fitness. -One recent view is that aging is caused by a combination of cellular maintenance requirements and evolutionary constraints. Among the key genetic and cellular processes that have been proposed to explain aging are those involving telomeres, free radicals, mitochondria, sirtuins, and the mTOR pathway. -According to hormonal stress theory, aging in the body's hormonal system can lower resilience and increase the likelihood of disease.

Why do we sleep?

A number of theories have been proposed about the functions of sleep, including evolutionary theory and sleep's role in survival; the role of sleep as a restorative function involving protein production and neural waste removal; and the role of sleep in brain plasticity. Sleep likely serves a number of important functions.

Adulthood and aging sleep

An increasing concern is that adults do not get enough sleep. In middle age, wakeful periods may interrupt nightly sleep more often. Many older adults go to bed earlier and wake up earlier. Almost half of older adults report having some insomnia.