Chapter 9 Flashcards
(41 cards)
Adolescence
Period following the onset of puberty during which a young person develops from a child into an adult
• One hundred years ago, adolescence began around age 15 and lasted a few months.
• Now adolescence lasts a decade or more.
Emerging adulthood (Adolescence)
A separate period from adolescence called emerging adulthood has been identified.
– Social sciences
Puberty
the time in life when a boy or girl becomes sexually mature.
• Is the time between the first onrush of hormones and full adult physical development
• Usually lasting three to five years
• Many more years are required to achieve psychosocial maturity.
Average ages and changes
Puberty
Usually between ages 10 and 14 for girls and ages 12 and 16 for boys.
Menarche
Puberty
Girl’s first menstrual period, signaling that she has begun ovulation
- Pregnancy is biologically possible but ovulation and menstruation are often irregular for years after menarche.
- Average age—about 12.5 years for normal-weight girls
Spermarche
Puberty
Boy’s first ejaculation of sperm
• Erections can occur as early as infancy, but ejaculation
signals sperm production
• Average age—just under 13 years
Hormones
Puberty
Body chemicals produced by the body to regulate many
biological processes.
- Various hormones influence thoughts, urges, emotions, and behavior.
- Hormones may underlie differences in psychopathology.
Gonads
Puberty Begins
Paired sex glands (ovaries in females, testicles in males).
• Gonads produce hormones and gametes.
Estradiol
Puberty Begins
Sex hormone, considered the chief estrogen. Females produce more estradiol than males do.
Testosterone
Puberty Begins
Sex hormone, the best known of the androgens (male hormones). Secreted in far greater amounts by males than by females.
Circadian rhythm
Body Rhythms
Day-night cycle of biological activity occurs approximately every 24 hours (circadian means “about a day”).
• Hormones cause a phase delay in sleep-wake cycles.
• Biology (circadian rhythms) and culture (parties and technology) work to make teenagers increasingly sleep-deprived with each year of high school.
Genes and gender
Reasons for Variations
About two-thirds of the variation in age of puberty is genetic.
• Genes on the sex chromosomes have a marked effect on age of puberty
onset.
• Girls generally develop ahead of boys.
Fat
Reasons for Variations
Children who have a relatively large proportion of body fat experience puberty sooner than do their thin contemporaries.
- Hormone affects appetite and is believed to be involved in the onset of puberty.
- In both sexes, chronic malnutrition delays puberty.
Stress
Reasons for Variations
Stress hastens (speeds up) the hormonal onset of puberty.
• Sick, drug-addicted, or divorced parents
• Violent and impoverished neighborhood
• Sexual abuse
• High level of family conflict
• International adoption at later age
Too early, too late
Puberty Begins
- Early-maturing GIRLS tend to have lower self-esteem, more depression, and poorer body image than later-maturing girls.
- Early-maturing BOYS are more aggressive, law-breaking, and alcohol-abusing than later- maturing boys.
- Slow developing boys tend to be more anxious, depressed, and afraid of sex.
Growth spurt
Becoming a Grown-Up
The rapid and intense increase in the rate of growth in height and weight that occurs during the adolescent stage of the human life cycle.
– Growth spurt is noted in the long bones of the body and most other skeletal systems
– Height spurt follows the increase in body fat, and then a muscle spurt occurs.
Growth spurt: Physical Changes
Becoming a Grown-Up
- Lungs triple in weight; consequently, adolescents breathe more deeply and slowly.
- Heart doubles in size and the heartbeat slows, decreasing the pulse rate while increasing blood pressure.
Skin and hair
Becoming a Grown-Up
• Skin becomes oilier, sweatier, and more prone to acne.
• Hair on the head and limbs becomes coarser and darker.
• New hair grows under arms, on faces, and over external sex organs.
– In many ways, hair is more than a growth characteristic; it becomes a display of sexuality
Primary sex characteristics
Sexual Maturation
Parts of the body that are directly involved in reproduction, including the vagina, uterus, ovaries, testicles, and penis.
Secondary sex characteristics
Sexual Maturation
Observable physical traits that are not directly involved in reproduction but that indicate sexual maturity, such as a man’s beard and a woman’s breasts.
Nutrients missing
Nutrition
- Only 16% of high school seniors eat recommended vegetable servings creating deficiency in intake of necessary vitamins or minerals.
- Menstruation and intensive physical labor or sports participation may deplete iron (iron-deficiency anemia).
Body image
Body Dissatisfaction
Person’s idea of how his or her body looks
– Girls diet partly because boys tend to prefer to date thin girls.
– Boys want to look taller and stronger partly because girls value well-developed muscles in males.
Self-acceptance
Body Dissatisfaction
• Self-acceptance is difficult • New changes may contribute to: – Distorted body image – Food obsession – Depression – Unhealthy consequences
Obesity
Eating Disorders
- Disorder at every age
- Rates falling in childhood but increasing in adolescence
- 2013: 15% of high school students in 22 states were obese.
