Ch. #5 Body, Brain, and Health

A male fetus will not develop male reproductive organs unless...

(1) A gene on his Y chromosome triggers the development of the testes (which are endocrine glands), and (2) the testes secrete the most important of the male hormones, testosterone.

Teens under the influence of alcohol are more likely to make additional risky choices (pt. #1):

1. They are more likely to smoke cigarettes, and the more they smoke, the more likely they are to become addicted to nicotine. 2. They are more likely to engage in risky sexual behaviors, including sex with multiple partners and unprotected sex. In turn, these behaviors are associated with unintended pregnancies and sexually transmitted diseases.

The area of the brain involved in inhibiting risky behavior is not fully developed until around age ________.

25.

Teens under the influence of alcohol are more likely to make additional risky choices (pt. #2):

3. They are more likely to get into a car where the driver has been drinking, which greatly increases the risk of an accident. 4. They are more likely to get into physical fights, experience academic problems, and engage in illegal behaviors.

What are concussions?

A brief loss of brain function in response to a hit or blow to the head. Immediate symptoms of concussion include headache, sensitivity to light and sound, feeling dizzy or foggy, and slowed reaction time.

What is adrenarche?

A circulation of adrenal hormones that contributes partly to such secondary sex characteristics as pubic and axillary (underarm) hair.

What is metabolic syndrome (MeTS)?

A combination of risk factors typically associated with obesity and includes high blood pressure, unhealthy cholesterol levels and diabetes.

What is an example of the orthogenetic principle?

A human starts as a single, undifferentiated cell. As growth proceeds, that single cell becomes billions of highly specialized cells (neurons, blood cells, liver cells, and so on). These differentiated cells become organized, or integrated, into functioning systems such as the brain or the digestive system.

Although HRT helps relieve physical symptoms of menopause, such as hot flashes and vaginal dryness, and prevents or slows osteoporosis, unfortunately...

A large government study that found that HRT increases women's chances of developing breast cancer and experiencing heart attacks and strokes.

What is the nucleus accumbens?

A part of the brain thought to be associated with reward, pleasure, and addiction.

What is a reflex?

A reflex is an unlearned and involuntary response to a stimulus, such as when the eye automatically blinks in response to a puff of air.

What is premenstrual dysphoric disorder (PDD)?

A severe form of PMS. PDD differs from PMS because it includes affective symptoms in addition to physical symptoms associated with the menstrual cycle, and it can be disabling - disrupting work and relationships.

There are many factors that can influence children's health and wellness, but three big areas of concern during this period of life are:

Accidents, nutrition, and physical activity levels.

How may our lifestyles inadvertently promote physical inactivity, which explain why the fitness levels of children have shown a measurable decline in recent years?

Across children of all ages, the average amount of TV viewing is 25 hours per week, and this does not include other screen time from computers and other devices.

The ________ is triggered by an increase in the level of growth hormones circulating through the body during adolescence.

Adolescent growth spurt.

How may pubertal changes prompt changes in family relations?

Adolescents physically distance themselves from their parents by engaging in less body contact, especially with fathers, and they go to great lengths to avoid being seen naked by their parents.

Adolescents have more sedentary lifestyles and consume more empty calories than they need, often in the form of beverages. Thus...

Adolescents who drink more calorie-dense, nutrient-poor beverages not only gain weight, they have higher systolic blood pressure.

How are adolescents with MeTS not operating at the same level of cognitive functioning as their non-MeTS peers?

Adolescents with MeTS scored slightly lower - 4 points - on overall IQ, but nearly 10 points lower on measures of math achievement. They also demonstrated some issues with attention and mental flexibility.

What is a neuron?

Although neurons differ in size and function, they all contain three main parts: the dendrites, which receive messages from adjacent neurons; the cell body; and the axon, which sends messages across the synapse to other neurons.

How are these early sleep patterns indicative of other behaviors (pt. #1)?

Among premature infants, those who transition smoothly from one state to another exhibit more mature neuro-cognitive outcomes than other premature infants.

Newborns used to be viewed as helpless little organisms, ill prepared to cope with the world outside the womb. We now know that they are quite well equipped to begin life. What can a newborn do?

Among the most important capabilities are reflexes, functioning senses, a capacity to learn, and organized, individualized patterns of waking and sleeping.

What is celiac disease?

An inherited digestive problem in which gluten (the proteins found in all wheat products) triggers an immune response that leads to inflammation and damages the small intestine.

What is andropause?

Andropause, also called age-associated hypogonadism, is characterized by slowly decreasing levels of testosterone and a variety of symptoms including low libido, fatigue and lack of energy, erection problems, memory problems, and loss of pubic hair.

Men do not experience the sharp drop in hormones that accompanies menopause in women. But some research has pointed to the possibility that men experience ________ as they age.

Andropause.

What is osteoporosis?

Another common affliction in old age is osteoporosis (meaning "porous bone"), a disease in which a serious loss of minerals leaves the bones fragile and easily fractured. It involves pain and can result in death if the victim falls and fractures a hip.

What are antioxidants?

Antioxidants, such as vitamins E and C, can donate one of their electrons to unstable free radicals, thereby neutralizing their damage to your body.

Many researchers adopting an error theory perspective have focused on preventing the damage caused by free radicals using what?

Antioxidants.

What are the short-term effects of being a late-developing boy (pt. #2)?

As a group, they even score lower than other students do, at least in early adolescence, on school achievement tests. However, on the positive side, late-maturing boys are less likely to drink alcohol during adolescence.

Their smaller size often means that others perceive them as younger and less mature. However...

As they proceed through puberty, though, boys show a decrease in anxiousness and feelings of worthlessness.

Why does early maturation appear to be more of a disadvantage than an advantage for girls (pt. #1)?

Because girls develop about two years earlier than boys do, an early-developing girl may be subjected to teasing or bullying for being the only one in her grade who is developed.

What explains the secular trend?

Better nutrition, advances in medical care, higher rates of obesity, and exposure to a wide array of chemicals that may alter hormone production are the major contributing factors.

Although psychosocial factors may also contribute to later bedtimes than in childhood (for example, doing homework or texting with friends late into the night), ________ - puberty in particular - seem primarily responsible.

Biological factors.

But they hope to be tall, hairy, and handsome, and they may become preoccupied with their physical and athletic prowess. Thus...

Boys who experience slow growth can experience a rocky emotional road during adolescence as the smallest kid in the class, the last picked for sports, and the one least likely to be noticed in a romantic way by peers who are more developed.

In both sexes, the changes involved in physical and sexual maturation are triggered when the hypothalamus of the brain stimulates activity in the endocrine system. Thus...

By the time sexual maturation is complete, however, males have larger quantities of male hormones (androgens, including testosterone) circulating in their blood than females do, whereas females have larger quantities of female hormones (estrogen, progesterone, and others).

Treatment for celiac disease in the form of a gluten-free diet restores absorption of nutrients and can lead to dramatic ________.

Catch-up growth.

Why do accidents constitute a major category of negative influences on children's health and well-being?

Childhood is unfortunately marked by numerous unintentional injuries, making accidents the leading cause of death throughout the childhood years.

Children should do at least 60 minutes of moderate or vigorous physical activity every day. Do they get this much activity?

Children tend to be sedentary, on average, for 63% of the time, somewhat active for 31%, and moderately to vigorously active just 6% of the time.

How does the thyroid gland also play a key role in physical growth and development and in the development of the nervous system (pt. #1)?

Children whose mothers had a thyroid deficiency during pregnancy can experience intellectual problems.

As a result of sports-related injuries, at least 25% of retired football players are expected to develop ________, a degenerative brain disease with symptoms of memory loss, poor impulse control, depression, and eventually dementia.

Chronic traumatic encephalopathy (CTE).

________ - defects that are present at birth, either from genetic factors or prenatal events - account for 1 out of 10 deaths during the first year.

Congenital malformations. Such malformations include heart defects, spina bifida, Down syndrome, cleft palates, and more.

The hemispheres "communicate" and work together through the ________, the superhighway of neurons connecting the halves of the brain.

Corpus callosum.

Other signs of brain degeneration besides neuron loss include:

Declines in the levels of important neurotransmitters; the formation of "senile plaques," hard areas in the tissue surrounding neurons that may interfere with neuronal functioning; and reduced blood flow to the brain, which may starve neurons of the oxygen and nutrients they need to function.

Branching, bushy ________ receive signals from other neurons, and the long axon of a neuron transmits electrical signals to other neurons or, in some cases, directly to a muscle cell.

Dendrites.

Rates of ________ - high levels of sugar in the blood leading to various health problems - have significantly increased in recent years among adolescents.

Diabetes.

What is the pituitary gland?

Directly controlled by the hypothalamus of the brain, it triggers the release of hormones from all other endocrine glands by sending hormonal messages to those glands.

Girls who experience puberty earlier than their peers report higher levels of depression at least for the period of time that they are out of synch. But which comes first?

Does being depressed ignite biochemical changes in the body, triggering early puberty and sexual activity? Or does experiencing early puberty and sexual activity lead to being depressed?

________ top the list of accidental causes of death for 1 to 4 year olds, and ________ cause the largest number of fatal injuries throughout childhood.

Drownings; crashes involving motor vehicles.

What are the short-term effects of being an early-developing boy (pt. #1)?

Early-developing boys are judged to be socially competent, attractive, and self-assured, and they enjoy greater social acceptance by their peers.

What is synaptic pruning?

Elimination of unnecessary or unused connections; the removal of unnecessary synapses that is also an important component of brain development.

The ________, in collaboration with the nervous system, is centrally involved in growth during childhood, physical and sexual maturation during adolescence, functioning over the life span, and aging later in life.

Endocrine system.

What is estrogen?

Estrogen increases dramatically at puberty, stimulating the production of growth hormone and the adolescent growth spurt, much as testosterone does in males. It is also responsible for the development of the breasts, pubic hair, and female sex organs and for the control of menstrual cycles throughout a woman's reproductive years.

In adolescent girls, the ovaries produce larger quantities of the primary female hormone, ________, and of ________.

Estrogen; progesterone.

Why is exercise important mentally and physically across the entire lifespan?

Exercise can improve cardiovascular and respiratory functioning, slow bone loss, and strengthen muscles.

Not all accidents are fatal. What injuries are minor and therefore do not constitute a major developmental obstacle?

Falls and being struck by something cause the largest number of nonfatal injuries during childhood, followed by such things as bee stings, bites, cuts, and overexertion.

Neither of these broad theories of aging has proved to be the explanation; instead, how are many interacting mechanisms involving both aging processes and disease processes at work?

For example, genes influence the capacity of cells to repair environmentally caused damage, and the random damage caused by free radicals alters genetic material.

If one hemisphere is damaged, how may it be possible for the other hemisphere to "take over" the functions lost?

For example, most children who have one hemisphere removed to try to reduce or eliminate severe seizures regain normal language function.

What is an example of reserve capacity?

For example, old and young people do not differ much in resting heart rates, but older adults, even if they are disease-free, will have lower maximal heart rates.

Even though one hemisphere might be more active than the other during certain tasks, how do they both play a role in all activities?

For example, the left hemisphere is considered the seat of language because it controls word content, grammar, and syntax, but the right hemisphere processes melody, pitch, sound intensity, and the affective content of language.

How do primitive reflexes typically disappear during the early months of infancy?

For instance, the grasping reflex becomes weak by 4 months and is replaced by voluntary grasping.

How do sex hormone levels in women shift drastically each month as they progress through their menstrual cycles?

For some women, these shifts may be accompanied by symptoms such as bloating, moodiness, breast tenderness, and headaches during the days just before the menstrual flow, symptoms collectively referred to as premenstrual syndrome (PMS).

According to one leading error theory, damage to cells that compromises their functioning is done by ________, which are toxic and chemically unstable by-products of metabolism.

Free radicals.

What psychological effects do the many changes associated with puberty have on girls?

Girls approaching or experiencing puberty tend to become self-conscious about their appearance and worry about how others will respond to them.

Some girls develop poor body images, possibly because they are bothered by the weight gains that typically accompany menarche. How are these weight gains not driven solely by pubertal changes?

Girls going through puberty report lack of energy and lower levels of activity, perhaps as a result of the hormonal changes but also a result of their increased feelings of self-consciousness. Many girls exhibit mood changes, which seem to escalate as they proceed through puberty.

The more obvious signs of sexual maturity emerge with increased production of ________ (those produced by the testes or ovaries): androgens in males and estrogen and progesterone in females.

Gonadal hormones.

What is the cephalocaudal principle?

Growth follows the cephalocaudal principle, according to which growth occurs in a head-to-tail direction.

By contrast, error theories of aging hold that we eventually succumb to what?

Haphazard destructive processes, such as those caused by free radicals - processes that result in increasingly faulty DNA and abnormal cell functioning and ultimately a breakdown in bodily functioning.

The most promising programmed aging theory is based on the work of Leonard Hayflick (1976) who discovered that cells from human embryos could divide only a certain number of times - 50 times, plus or minus 10 - an estimate referred to as the ________.

Hayflick limit.

The weight and the blood pressure put teens at risk for later health problems, including:

Heart and kidney disease, diabetes, liver problems, and arthritis.

Why are teens also more likely to experience conflicts with their parents, especially with their mothers?

Hormone changes in early adolescence may contribute to this increased conflict with parents and to moodiness, bouts of depression, lower or more variable energy levels, and restlessness.

________, or taking estrogen and progestin to compensate for hormone loss at menopause, was considered an effective cure for the symptoms that some women experience with menopause.

Hormone replacement therapy (HRT).

About two-thirds of women in U.S. society experience ________. Many also experience vaginal dryness and irritation or pain during intercourse.

Hot flashes.

Even though many primitive reflexes are not very useful to infants, how have they proven to be useful in diagnosing infants' neurological problems?

If such reflexes are not present at birth - or if they last too long in infancy - physicians know that something is wrong with a baby's nervous system. The presence and then the absence of reflexes can serve as a general indicator of neurological health.

How do sex hormones also have psychological implications and effect the experience of aging in men?

In men, testosterone levels fluctuate annually, with peak levels detected in spring and lower levels in fall, and daily, with peak levels in the morning. Men with high levels of testosterone tend to be more sexually active and aggressive than other men.

Instead of developing identically, the functions controlled by the hemispheres diverge. What does the left hemisphere control?

In most people, the left cerebral hemisphere controls the right side of the body and is adept at the sequential processing needed for analytic reasoning and language processing.

But perhaps more concerning are the longer-term effects of concussions. The brains of those who had experienced a concussion showed abnormalities in the frontal cortex. Thus...

In particular, there was damage to the parts of the brain associated with memory and regulation of mood.

What does it mean for older adults that both degeneration and plasticity - both losses and gains - characterize the aging brain?

In some people, degeneration may win and declines in intellectual performance will occur. In other people, plasticity may prevail; their brains may form new and adaptive neural connections faster than they are lost so that performance on some tasks may actually improve with age.

When does the brain complete its development?

In the past, we have answered that the brain is fully developed by the end of infancy, or even by the end of pregnancy. Today, however, the answer is that brain development is never truly complete.

Researchers have uncovered evidence that certain health conditions such as stroke and epilepsy may ________ neurogenesis, whereas other conditions such as depression may ________ it.

Increase; decrease.

How are these early sleep patterns indicative of other behaviors (pt. #2)?

Infants with poor sleep habits at 12 months of age are reported to have problems with attention regulation as well as behavior problems at 3 to 4 years of age.

Biological changes ________ with psychological characteristics of the person and with changes in the social environment to influence how adolescence is experienced.

Interact.

Physical and sexual maturation are the products of an ________ between heredity and environment, with some environments delaying maturation and others hastening it.

Interaction.

The brain displays plasticity early in life and signs of neurogenesis and synaptogenesis throughout life. Thus...

It can change in response to physical and mental exercise. It may be able to regenerate some functions following injury, which holds promise for patients with a wide range of conditions such as stroke, epilepsy, and degenerative diseases such as Parkinson's and Alzheimer's.

Many of us believe that stress ages people; now there is concrete evidence that stress speeds cellular aging. Moreover...

Lack of exercise, smoking, obesity, and low socioeconomic status - all risk factors for age-related diseases - are also associated with short telomeres.

What are the short-term effects of being a late-developing boy (pt. #1)?

Late maturation in boys has more negative effects. Late-maturing boys tend to be more anxious and less sure of themselves, and they experience more behavior and adjustment problems.

One important feature of the developing organization of the brain is the ________, or asymmetry and specialization of functions, of the two hemispheres of the cerebral cortex.

Lateralization.

In contrast the brain's "white matter," consisting of clusters of axons, increases in ________ fashion throughout adolescence, a likely result of the steady progression of myelination of axons.

Linear.

How does the brain undergo much change during adolescence?

Magnetic resonance imaging (MRI) studies show that the brain's "gray matter," made up primarily of cell bodies and dendrites, undergoes change in an inverted-U pattern across adolescence.

Acute illnesses such as colds and infections become less frequent from childhood on, but what chronic diseases and disorders become more common?

Many of the 70-and-older age group have at least one chronic impairment - whether a sensory loss, arthritis, hypertension, or a degenerative disease.

More than the species-specific ________, an individual's genetic makeup, combined with environmental factors, influences how rapidly he ages and how long he lives compared with other humans.

Maximum life span.

The changes associated with andropause in men are more gradual, more variable, and less complete than those that are associated with menopause in women. As a result...

Men experience fewer psychological effects.

For girls, the most dramatic event in the sexual maturation process is ________ - the first menstruation - normally between ages 11 and 15, with an average of about 12.5 years.

Menarche.

The ending of a woman's menstrual periods in midlife is called ________.

Menopause. Levels of estrogen and other female hormones decline so that the woman who has been through menopause has hormones that are less "feminine" and more "masculine" than that of the premenopausal woman.

What is menstruation?

Menstruation is the process of shedding the lining of a uterus prepared to support a fertilized egg.

Free radicals have also been implicated in what major diseases that become more common with age?

Most notably, cardiovascular diseases, cancer, and Alzheimer's disease. Moreover, they are implicated in the aging of the brain.

How can both physical and mental activity, along with a positive attitude, help slow the effects of aging on both the body and brain?

Muscles atrophy if they are not used, and the heart functions less well if a person leads a sedentary life. The brain also needs "mental exercise" to display plasticity and to continue to function effectively in old age.

________ begins prenatally but continues for many years after birth, proceeding from the spinal cord to the hindbrain, midbrain, and forebrain.

Myelination.

The brain is responsive to experience and is capable of ________, the process of generating new neurons, across the lifespan.

Neurogenesis.

As people age, more of their neurons atrophy or shrivel, transmit signals less effectively, and ultimately die. However...

Neuron loss is greater in the areas of the brain that control sensory and motor activities than in either the association areas of the cortex (involved in thought) or the brain stem and lower brain (involved in basic life functions such as breathing).

What is myelination?

Neurons becoming encased in this protective substance that speeds transmission.

Most systems increase to a peak sometime between childhood and early adulthood and decline slowly thereafter. Thus...

No matter what physical function you look at - the capacity of the heart or lungs to meet the demands of exercise, the ability of the body to control its temperature, the ability of the immune system to fight disease, or strength - the gradual effects of aging are evident.

Many people fear that aging means losing brain cells and ultimately becoming senile. However...

Normal aging is associated with gradual and relatively mild degeneration within the nervous system - some loss of neurons, diminished functioning of many remaining neurons, and potentially harmful changes in the tissues surrounding and supporting the neurons, such as the protective myelin covering.

Adolescents, relative to children and adults, exhibited higher levels of activity - hyper-responsiveness - in the ________ in anticipation of both negative and positive consequences of risk taking.

Nucleus accumbens.

As with children, the number of teens who meet the criteria for ________ - being 20% or more above the "ideal" weight for height, age, and sex - is increasing.

Obesity.

How does nutrition continue to be a important contributor to health throughout childhood as it was during infancy (pt. #1)?

Of the total calories consumed by children every day, 27% come from snacks. That might be fine if the snacks were healthy, but they tend to be sugary, salty, fatty, and low in nutrients.

How do the effects of the timing of puberty depend on the adolescent's perception of whether pubertal events are experienced early, on time, or late?

One girl may believe she is a "late bloomer" when she does not menstruate until age 14; but another girl, who exercises strenuously, may believe that menarche at age 14 is normal because delayed menarche is typical of athletes.

How might brain changes during adolescence relate to risky behavior? What is the first thing to consider?

One is that the part of the brain involved in regulating self-control has not yet matured. At some point, there may have been evolutionary advantages to this, but at this point, it seems to make teens vulnerable to potentially harmful behaviors.

How do the health problems associated with premature delivery and low birth weight often continue to challenge infants throughout their first year and beyond?

Only about 12% of babies in the United States are premature, but complications of premature birth account for 35% of infant deaths.

What is osteoarthritis?

Osteoarthritis is a common joint problem that results from gradual deterioration of the cartilage that cushions the bones from rubbing against one another. For some older adults, the joint disease is deforming and painful and limits their activities.

Family-member reactions to an adolescent's pubertal changes are also instrumental in determining the adolescent's adjustment. How may this help explain the difference in adjustment between early-maturing boys and early-maturing girls?

Parents may be more concerned and negative about their daughter's emerging sexuality than they are about their son's. These attitudes may be inadvertently conveyed to teens, affecting their experience of puberty and their self-concept.

Children who achieve the recommended level of physical activity are more physically fit than children who lead a more sedentary lifestyle. How do the benefits of exercise go beyond physical fitness?

Physical activity enhances cognitive and psychological functioning.

What determines an adolescent's rate of development?

Physical and sexual maturation, then, are processes set in motion by the genes and executed by hormones. But environment also plays its part in the timing of maturation.

The most critical of the endocrine glands is the ________, the so-called master gland located at the base of the brain.

Pituitary gland.

Although males express a mix of positive and negative reactions to becoming sexually mature, they generally react more ________ to semenarche than girls do to menarche.

Positively. 62% of boys regard semenarche positively, whereas only 23% of girls view menarche positively.

What is progesterone?

Progesterone is sometimes called the "pregnancy hormone" because it orchestrates bodily changes that allow conception and then support a pregnancy.

________ propose that aging follows a predictable genetic timetable; ________ call attention to more haphazard processes that cause damage or errors in cells to accumulate and organ systems to deteriorate.

Programmed theories of aging; damage or error theories of aging.

Why is another health issue that seems to plague many teenagers is insufficient sleep?

Puberty ushers in changes in the sleep-wake cycle, melatonin production, and circadian rhythms, which can shift the "natural" time for falling asleep later and later.

Newborns spend half of their sleeping hours in active sleep, called ________ (for the rapid eye movements that occur during it).

REM sleep.

Why has one researcher referred to exercise as "brain food"?

Regular physical activity seems to support effective executive functions, those important cognitive activities involved in planning and executing goal-directed behaviors.

What determines how fast telomeres shorten?

Research is revealing that chronic stress, such as that involved in caring for an ill child or a parent with dementia, is linked to shorter than normal white-blood-cell telomeres, which in turn are associated with heightened risk for cardiovascular disease and death.

Another fact of physical aging is a decline in the ________ of many organ systems - that is, their ability to respond to demands for extraordinary output, such as in emergencies.

Reserve capacity.

The marker of sexual maturation most like menarche in girls is ________, or a boy's first ejaculation - the emission of seminal fluid in a "wet dream" or while masturbating.

Semenarche.

Why must infants move from short sleep-wake cycles distributed throughout the day and night to a pattern that includes longer sleep periods at night with longer wake periods during the day?

Settling into an organized sleep-wake pattern is an indication that the baby's nervous system is developing as expected and is beginning to integrate a myriad of external signals with internal states.

When does the brain become lateralized?

Signs of brain lateralization are clearly evident at birth. Newborns are more likely to turn their heads to the right than to the left and some clearly prefer the right hand in their grasp reflex. Newborns may also show more left hemispheric response to speech sounds.

What are more noticeable signs of aging in our 40s and 50s?

Skin becomes wrinkled, dry, and loose, especially among people who have spent more time in the sun. Hair thins and turns gray from loss of pigment-producing cells. And to most people's dismay, they put on extra weight throughout much of adulthood as their metabolism rate slows but their eating and exercise habits do not adjust accordingly.

Why do young infants sleep so much and spend so much more time in REM sleep than adults?

Sleep patterns in infancy are associated with brain maturation and plasticity. REM sleep, in particular, may be important for learning and memory processes.

________ is the best way to describe the growth that occurs throughout much of childhood. From age 2 until puberty, children gain about 2-3 inches and 5-6 pounds every year.

Slow and steady.

How does nutrition continue to be a important contributor to health throughout childhood as it was during infancy (pt. #2)?

Sodas not only contribute to weight gain and obesity, they are also associated with lower consumption of milk and intake of calcium, an important nutrient for bone health.

How can even the environments that encourage the most activity not turn every couch potato into an athlete?

Some children are predisposed by temperament to lead more sedentary lifestyles and resist even the most engaging playground equipment and incentives to be physically engaged.

What are survival reflexes?

Some reflexes are called survival reflexes because they have clear adaptive value. Examples include the breathing reflex (useful for obvious reasons), the eye-blink reflex (which protects against bright lights or foreign particles), and the sucking reflex (needed to obtain food).

What are telomeres?

Stretches of DNA that form the tips of chromosomes and that shorten with every cell division.

What are hot flashes?

Sudden experiences of warmth and sweating, usually centered around the face and upper body, that occur at unpredictable times, last for a few seconds or minutes, and are often followed by a cold shiver.

The axon of one neuron makes a connection with another neuron at a tiny gap called a ________.

Synapse. By releasing neurotransmitters stored at the ends of its axons, one neuron can either stimulate or inhibit the action of another neuron.

Between 7 and 15 years of age, there is another process at work: ________.

Synaptic pruning.

Between birth and 7 years of age, there is a tremendous amount of ________.

Synaptogenesis.

Pre-existing and persistent early childhood differences in mental health-related indicators among children who experience early puberty. Thus...

Teens are not becoming depressed or engaging in problem behaviors because they have experienced early puberty, but they experienced early puberty because of underlying conditions present long before the first observable signs of puberty.

What are the consequences for teens who do not get enough sleep?

Teens who sleep less at night report higher levels of depression, irritability, and lack of tolerance for frustration. They may also have difficulty controlling their emotional responses, which leads to greater expression of aggression or anger.

Although adolescents as a group may be more prone to risk-taking behaviors, why is it not the case that all adolescents engage in the same level of risk taking?

Teens with stronger working memory skills are less likely to take risks than their peers with weaker working memory skills. In addition, a positive relationship between teens and their parents can help protect them during this period of development.

The mechanism behind the cellular aging clock suggested by Hayflick's limit on cell division has turned out to be ________.

Telomeres.

Progression through puberty and attainment of sexual maturity is often measured using the "Tanner Scale." What is the Tanner Scale?

The Tanner Scale includes five stages ranging from prepubertal -no evidence of secondary sexual characteristics - to adult secondary sexual characteristics.

What is myelin?

The axons of many neurons become covered by a fatty sheath called myelin, which acts like insulation to speed the transmission of neural impulses.

Free radicals are produced when oxygen reacts with certain molecules in the cells. They have an unpaired, or "free," electron and are highly reactive with and damaging to other molecules in the body, including DNA. Thus...

The body's mechanisms for repairing such genetic damage simply cannot keep up with the chaos. More cells then function improperly or cease to function, and the organism eventually dies.

What is plasticity?

The brain, especially early in its formation, has great plasticity; that is, it is responsive to the individual's experiences and can develop in a variety of ways.

During middle childhood (ages 6-11), children may seem to grow little, probably because the gains are small in proportion to the child's size (4-4½ feet and 60-80 pounds on average) and therefore harder to detect. What principles of growth are operating here?

The cephalocaudal and proximodistal principles of growth continue to operate. As the lower parts of the body and the extremities fill out, the child takes on more adultlike body proportions. The bones continue to grow and harden, and the muscles strengthen.

What are the three general principles that underlie growth?

The cephalocaudal principle, the proximodistal principle, and the orthogenetic principle.

What is synaptogenesis?

The development of connections between neurons; the growth of synapses.

Why does early maturation appear to be more of a disadvantage than an advantage for girls (pt. #2)?

The early-maturing girl expresses higher levels of body dissatisfaction than her prepubertal classmates and may engage in unsafe dieting and exercising as a result of this discomfort.

How do psychological and social factors that influence women's reactions to sexual maturation and to their menstrual cycles also influence the severity of menopausal symptoms?

The effect of menopause is colored by the meaning it has for the woman, as influenced by her society's prevailing views of menopause and by her own personal characteristics.

What are endocrine glands?

The endocrine, or hormonal, system consists of a group of endocrine glands that secrete chemicals called hormones directly into the bloodstream.

Most cases of erectile dysfunction are caused by medical conditions such as diabetes and not by lower hormone production. Thus...

The erectile dysfunction among older men is often treatable with sildenafil, also known as Viagra.

Children and adolescents whose parents are overweight have what twin risk factors for becoming overweight themselves?

The genes that their parents have passed along to them that may predispose them to be overweight, and the environment that is cultivated for them by overweight parents.

What are gonadal hormones?

The gonadal hormones are primarily responsible for the development of secondary sexual characteristics and sexual maturity. This increased hormone production will also trigger sexual thoughts, feelings, and maturation.

The developing brain is highly vulnerable to damage if it is exposed to drugs or diseases or if it is deprived of sensory/motor experiences. However...

The highly adaptable brain can often recover successfully from injuries. Neurons that are not yet committed to their specialized functions can often take over the functions of damaged neurons. Moreover, the immature brain is especially able to benefit from stimulating experiences.

What is the secular trend?

The historical trend in industrialized societies toward earlier maturation and greater body size.

What is erectile dysfunction?

The inability to achieve or sustain an erection for intercourse despite having sufficient levels of testosterone.

The adrenal glands secrete androgen-like hormones that contribute to the maturation of the bones and muscles in both sexes. Thus...

The maturation of the adrenal glands during middle childhood results in sexual attraction well before puberty in both boys and girls and relates to sexual orientation in adulthood.

Evidence for the genetic control of aging and dying comes from what various sources?

The maximum life span, the role of individual genetic makeup in longevity, the Hayflick limit on cell replication timed by telomeres, changes in the activity of certain genes as we age, and systematic changes in several bodily systems.

What is the nervous system?

The nervous system consists of the brain and spinal cord (central nervous system) and the neural tissue that extends into all parts of the body (peripheral nervous system).

Why do teens experience a higher threshold for reward prior to attaining adult levels of decision making?

The neurons serving the frontal lobes are among the last areas of the brain to become myelinated.

Children born small for their gestational age are often shorter as adults. Treatment with synthetic growth hormones can lead to near-expected adult height if administered early - well before the start of puberty. However...

The physical gains from taking the medication are around 2 inches of height and it is not clear whether these small gains add significantly to quality of life.

What is growth hormone?

The pituitary produces growth hormone, which triggers the production of specialized hormones that directly regulate growth.

The average woman experiences menopause at age 51, and the usual age range is from 45 to 54. Moreover...

The process takes place gradually over 5-10 years as the periods become either more or less frequent as well as less regular.

What is puberty?

The processes of biological change that result in an individual's attaining sexual maturity and becoming capable of producing a child.

What is the proximodistal principle?

The proximodistal principle of growth can be seen during the prenatal period, when the chest and internal organs form before the arms, hands, and fingers.

Instead of developing identically, the functions controlled by the hemispheres diverge. What does the right hemisphere control?

The right hemisphere generally controls the left side of the body and is skilled at the simultaneous processing of information needed for understanding spatial information and processing visual-motor information as well as the emotional content of information.

How might brain changes during adolescence relate to risky behavior? What is the second thing to consider?

The second thing to consider is adolescence ushers in a period of increased responsiveness to rewards. Indeed, the reward system of the brain is hyper-responsive: The adolescent brain has greater need for reward, which leads to more reward-seeking behaviors.

How do male sex hormones become highly important again during adolescence?

The testes of a male secrete large quantities of testosterone and other male hormones (called androgens).

What is a critical or sensitive period for brain development?

The time when it proceeds most rapidly is during the late prenatal period and early infancy.

What psychological effects do the many changes associated with puberty have on boys?

Their body images are more positive than those of girls, and they are more likely to welcome their weight gain and voice changes.

The frontal lobes are essential to many higher-order mental activities of thinking, planning, and decision making. Thus, how may these brain changes leave adolescents in a vulnerable position?

Their desire for reward increases before their ability to think through all the consequences of their actions.

Celiac disease leaves affected children unable to absorb nutrients from food despite adequate consumption. Thus...

Their disease, if untreated, can lead to malnutrition, which stunts growth and delays puberty.

What are the short-term effects of being an early-developing boy (pt. #2)?

There are some negative aspects of being an early-maturing boy, namely increased risk of earlier involvement in substance use and other problem behaviors such as bullying, aggression, and delinquency.

What are androgens?

These hormones stimulate the production of growth hormone, which in turn triggers the adolescent growth spurt. Androgens are also responsible for the development of the male sex organs and contribute to sexual motivation during adulthood.

How can spending the first few years of life in impoverished families and neighborhoods lead to less gray matter, the brain tissue believed to be involved in information processing?

These youngsters start life with the same amount of gray matter as those from wealthier families and neighborhoods, but they experience slower rates of brain growth during infancy and early childhood.

Early maturity seems to alter girls' social environments, thrusting them into socializing with older peers, at least when they are outside of the highly age-organized setting of their classrooms. As a result...

They are likely to become involved in dating, smoking, drinking, having sex, and engaging in minor troublemaking at an early age.

Why are adolescents notorious for taking chances that most adults would not take?

They often display poor judgment and decision making when it comes to alcohol, drug, and cigarette use; sexual activities; and driving.

What is catch-up growth?

This catch-up growth after a period of malnutrition or illness reflects the body's struggle to get back on the growth course it is genetically programmed to follow.

What is the orthogenetic principle?

This means that development starts globally and undifferentiated and moves toward increasing differentiation and hierarchical integration.

Why does the volume of gray matter increase, peak, and then decrease throughout the teen years?

This pattern is believed to be associated with increased synaptogenesis just before puberty, followed by a period of heightened pruning of synapses.

What are primitive reflexes?

Those called primitive reflexes are not clearly useful; many are believed to be remnants of evolutionary history that have outlived their purpose. The Babinski reflex is a good example.

How does the thyroid gland also play a key role in physical growth and development and in the development of the nervous system (pt. #2)?

Thyroid deficiency during infancy can also lead to intellectual disability and slow growth if unnoticed and untreated.

Do differences between early and late developers persist into later adolescence and adulthood?

Typically, the effects of being out of synch are greatest during the time when the adolescent is most noticeably different from others.

However, the damage of most concern is damage to DNA, because the result is more defective cells replicating themselves. Thus...

Unfortunately, we cannot live and breathe without manufacturing free radicals.

For the average boy, the sexual maturation process begins around age 11 to age 11½ with an initial enlargement of the testes and scrotum (the saclike structure that encloses the testes). Then...

Unpigmented, straight pubic hair appears soon thereafter, and about 6 months later, the penis grows rapidly about the same time that the adolescent growth spurt begins.

Aamage or error theories generally propose that ________ - accumulation of random damage to cells and organs over the years - ultimately causes death.

Wear and tear.

What happens when menopause is complete?

When menopause is completed, a woman is no longer ovulating, no longer menstruating, and no longer capable of conceiving a child.

Typically, menopause had no effect on the women's levels of anxiety, anger, perceived stress, or job dissatisfaction. Thus...

When women do experience severe psychological problems during the menopausal transition, they often had those problems well before the age of menopause.

Late-maturing girls (like late-maturing boys) may experience some anxiety as they wait to mature, but why do they not seem to be as disadvantaged as late-maturing boys?

Whereas later-developing boys tend to perform poorly on school achievement tests, later-developing girls outperform other students. Perhaps late-developing girls focus on academic skills when other girls have shifted some of their focus to extracurricular activities.

Why do some women experience more severe menopausal symptoms than others do?

Women who have a history of menstrual problems (such as PMS) report more menopausal symptoms, both physical and psychological. Thus, some women may experience greater biological changes or be more sensitive to them.

How can the lifespan developmental perspective be applied to health and wellness (pt. #1)?

• Health is multidimensional. • Health is determined by both genetic and environmental influences. • Health involves both gains and losses; health both improves and declines over the life span in response to many factors.

How can the lifespan developmental perspective be applied to health and wellness (pt. #2)?

• Health occurs in a sociohistorical context and can be enhanced or constrained by the social and historical factors that contribute to it. • Health is a lifelong process. It is influenced by personal choices over the life span and is constantly changing in response to these choices.

How does myelination have numerous implications for developmental changes observed across the lifespan (pt. #1)?

• Myelination in the visual cortex is largely complete by age 1, consistent with advances in visual skills over the first year. • Toddlers experience a vocabulary spurt following a period of rapid myelination of those parts of the brain involved in language development.

How does myelination have numerous implications for developmental changes observed across the lifespan (pt. #2)?

• Teenagers are more likely than children to ask hypothetical "what if" questions and to reason about weighty abstractions, such as truth and justice, owing to myelination within the prefrontal lobes during adolescence. • Continued myelination into adulthood may account for adults being better able than teenagers to integrate thoughts and emotions, allowing them to think more clearly in situations where emotions are running high.