Physical Development in Adolescence

1
Physical Development in Adolescence

• Lecture 15
• C6035 Human Development

2
Biological and Sociohistorical Nature of
Adolescence

• G. Stanley Hall -father of the scientific study
  of adolescence-ideas first published in 1904 in a
  two-volume set titled Adolescence
• All development is controlled by genetically
  determined physiological factors
• Environment plays minimal role in development,
  especially during infancy childhood
• Storm and stress view is Halls concept that
  adolescence is turbulent time-charged with
  conflict mood swings

3
Inventionist View

• Adolescence is a sociohistorical creation
• At turn of 20th century, legislation ensured
  dependency of youth helped make their move into
  economic sphere more manageable
• Schools, work economics are important
  dimensions of inventionist view of adolescence

4
Todays Youth

• By some criteria, todays adolescents are doing
  better than their counterparts from decade or two
  earlier
• More adolescents complete high school
• Majority have positive self-concept positive
  relationships with others
• Majority of adolescents experience transition to
  adulthood more positively, many today are not
  provided with adequate opportunities support to
  become competent adults
• High divorce rates, high adolescent pregnancy
  rates, increased geographic mobility of families
  contribute to this lack of stability in their
  lives

5
Pubertys Boundaries Determinants

• Puberty period of rapid physical maturation
  involving hormonal bodily changes that occur
  primarily during early adolescence
• Menarche girls first menstruation, occurs at
  approximately age 12 to 13, but has been
  declining an average of about 4 months per decade
  for past century
• Key factor in pubertys occurrence is body
  mass-body weight approximating 106 (plus or minus
  3 pounds) can trigger menarche
• Pubertys determinants include nutrition, health,
  heredity body mass-except for menarche, which
  occurs rather late in puberty, no single marker
  heralds its coming

6
(No Transcript)
7
(No Transcript)
8
Hormonal Changes

• Hormones powerful chemical substances secreted
  by endocrine glands carried through body by
  bloodstream
• Hypothalamus structure in higher portion of
  brain that monitors eating, drinking sex
• Pituitary gland important endocrine gland
  controls growth regulates other glands
• Gonads sex glands - testes in males ovaries in
  female

9
Hormones

• Two primary classes of hormones
• Androgens male sex hormones
• Estrogens female sex hormones
• Testosterone androgen plays important role in
  male pubertal development
• Estradiol estrogen plays important role in
  female pubertal development

10
(No Transcript)
11
Height, Weight Sexual Maturation

• Peak rate of pubertal change occurs at 11.5 years
  for girls and 13.5 years for boys
• During their growth spurt, girls increase in
  height about 3-1/2 inches per year, boys about 4
  inches
• Boys girls who are shorter or taller than their
  peers before adolescence are likely to remain so
  during adolescence
• Marked weight gains coincide with onset of
  puberty - Girls tend to outweigh boys, but by
  about age 14, boys begin to surpass girls

12
Sexual Maturation

• Three most noticeable areas of sexual maturation
  in boys are penis elongation, testes development
  growth of facial hair
• Pubertal changes in females unfold in less
  clear-cut way than they do in males - breasts
  enlarge or pubic hair appears - later hair
  appears in armpits
• As these changes occur female grows in height-her
  hips become wider than her shoulders

13
Menarche and the Menstrual Cycle

• Pubertal changes such events as menarche,
  produce different body that requires considerable
  change in self-perception, possibly resulting in
  identity crisis
• In one study of 639 girls, most of the girls
  described their first period as a little
  upsetting, a little surprising, or a little
  exciting and positive that menarche was an
  index of their maturity - most frequent negative
  aspects reported were hassle messiness

14
Body Image

• Preoccupation with ones body image is strong
  throughout adolescence, but it is especially
  acute during puberty
• In general, girls are less happy with their
  bodies have more negative body images
• As pubertal change proceeds, girls often become
  more dissatisfied with their bodies, while boys
  become more satisfied

15
Early and Late Maturation

• In a Berkeley Longitudinal Study, early-maturing
  boys perceived themselves more positively had
  more successful peer relationships than did their
  late-maturing counterparts
• More recent research confirms that at least
  during adolescence, it is advantageous to be an
  early-maturing rather than late-maturing boy
• In the sixth grade, early-maturing girls show
  greater satisfaction with their figures than do
  late-maturing girls, but by tenth grade
  late-maturing girls are more satisfied

16
Pubertal Timing and Health Care

• Many adolescents whose development is extremely
  early or late are likely to come to the attention
  of a physician
• These adolescents may have fears concerns about
  normal growth which may never be addressed by
  professionals
• Early-maturing girls, especially, benefit from
  discussions with health-care providers or
  counselors concerning peer pressures, dating
  practices how to engage in adult like behavior
  at an early age

17
Leading Causes of Death in Adolescence

• 3 leading causes of death in adolescence
  accidents, suicide, homicide
• More than ½ of all deaths ages 10 to 19 due to
  accidents most involve motor vehicles
• In about 50 of motor vehicle fatalities
  involving an adolescent driver has blood alcohol
  level of 0.10
• Suicide accounts for 6 of deaths in 10-14 age
  group 12 in 15-19 age group.
• Homicide is high among African-American males
  adolescent who are 3 times more likely to be
  killed by guns than by natural causes

18
Heterosexual Attitudes Behavior

• In national survey of adolescents, sexual
  intercourse was uncommon in early adolescence but
  more common in high school college years
• 8 in 10 girls 7 in 10 boys are virgins at age
  15
• Probability that adolescents will have sexual
  intercourse increases steadily with age
• Initial sexual intercourse occurs in mid to late
  adolescent years for most teenagers
• Most adolescent females first voluntary sexual
  partners are either younger, same age, or no more
  than two years older

19
(No Transcript)
20
(No Transcript)
21
Homosexual Attitudes Behavior

• 4 males 3 females are exclusively homosexual
• More than 6 of 18-year-olds say they had
  predominantly homosexual attractions
• Among biological factors believed to be involved
  in homosexuality are prenatal hormone conditions
• Adolescence may play an important role in the
  development of homosexuality

22
Contraceptive Use

• Although adolescent contraceptive use is
  increasing, many sexually active teens do not use
  contraceptives
• Sexually active younger adolescents are less
  likely to take contraceptive precautions than
  older adolescents
• In one study, more adolescent females than males
  reported changing their behavior in direction of
  safer sex practices

23
Sexually Transmitted Diseases

• Teenagers tend to believe that
• Sexually transmitted diseases (STD) always happen
  to someone else
• STDs can be easily cured without any harm done
• STDs are too disgusting for a nice young person
  to even hear about, let alone get
• STDs are fairly common among todays adolescents

24
(No Transcript)
25
Sexually Transmitted Diseases

• Chlamydia named for bacteria that causes it,
  affects as many as 10 of all college males
  females
• Herpes Simplex Virus II symptoms include
  irregular cycles of sores blisters in genital
  area-although disease is more common among young
  adults - as many as 1 in 35 adolescents have
  genital herpes
• Syphilis tiny bacterium that requires warm,
  moist surfaces to penetrate body -Penicillin is
  successful treatment for syphilis

26
AIDS (acquired immune deficiency syndrome)

• Caused by human immunodeficiency virus (HIV)-
  which destroys bodys immune system
• Many germs that usually would not harm a person
  with healthy immune system can produce
  devastation death in persons with AIDS
• Number of AIDS cases reported in 13-19 age group
  has increased each year since 1981 to almost
  2,184 cases in 1995
• Since average latency time from viral infection
  to time of illness is about five to seven years,
  most infected adolescents would not become ill
  until they are adults

27
(No Transcript)
28
Adolescent Pregnancy

• Each year, more than 500,000 American teenagers
  become pregnant, more than 70 percent of them
  unmarried
• More than 200,000 females in U.S. have a child
  before their 18th birthday
• The rate is lower now that it was in the 1950s
  and 1960s

29
Steady rise in number of nonmarried teenage
pregnancies

• 2 to 3 decades ago if an unwed adolescent girl
  became pregnant - her parents often had her
  swiftly married in shotgun wedding
• Today, however, there is less stigma attached to
  a illegitimacy
• Adolescent pregnancy rate in U.S. is much higher
  than in other industrialized countries
• It is more than twice as high as rates in
  England, France Canada

30
Substance Use and Abuse

• Proportion of 8th graders taking illicit drugs in
  past 12 months nearly doubling since 1991
• Among 10th graders - annual marijuana use nearly
  doubled from 15 in 1992 to 34 in 1996
• Among 12th graders it has risen to 36- 14
  increase since 1992
• In 65 of aggressive male acts against
  females-offender is under influence of alcohol
• Each year, approximately 25,000 people are killed
  1.5 million injured by drunk drivers
• Data from college students show increase in heavy
  drinking underscored by high profile cases of 18
  and 19 year-olds dying from alcohol poisoning as
  a result of binge drinking

31
(No Transcript)
32
Adolescent smoking

• Peaked in mid 70s, then declined through 1980
• In 90s adolescent cigarette smoking increased
  with 19 of 8th graders and 28 of 10th graders
  reported daily use of tobacco
• Some peer group programs such as Keep It Clean
  Health Olympics have had some success in
  preventing curbing teen tobacco use

33
Eating Disorders

• America is a nation obsessed with food, spending
  extraordinary amount of time thinking about,
  eating avoiding food
• Eating disorders are complex, involving genetic
  inheritance, physiological factors, cognitive
  factors environmental experiences
• Anorexia nervosa involves relentless pursuit of
  thinness through starvation, eventually causing
  death
• Bulimia individual consistently follows
  binge-and-purge eating pattern.

34
Cognitive and Sociocultural Factors in Adolescent
Health

• While adolescents usually recognize that
  substance abuse unprotected sexual intercourse
  are potential health hazards, they often
  underestimate negative consequences
• Because there are large within-group differences
  in living conditions lifestyles of ethnic
  minority groups, sociocultural factors are not
  always recognized
• Poverty is related to poor health in adolescents
  which is contributed by insufficient family
  income, few role models, strong influence of
  peers lack of appropriate medical care

35
Health Services

• Among the chief barriers to better health
  services for adolescents are cost, poor
  organization unavailability of health services
• Few health care workers receive any special
  training for working with adolescents