Chapter 14 Puberty
What happens when puberty begins?
-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. -Girls generally develop ahead of boys. -Children who have a relatively large proportion of body fat experience puberty sooner than do their thin contemporaries.
Define leptin
-Affects appetite and is believed to be involved in the onset of puberty -Increases during childhood and peaks at around age 12 -Evokes uncertainty about its effects
Weight and height increase _____ and _______
-Before muscles and internal organs -Higher risk for sports injuries
According to the DSM-5, bulemia is officially diagnosed when three symptoms are evident:
-Binging and purging at least once a week for three months -Uncontrollable urges to overeat -Sense of self inordinately tied to body shape and weight
Define body fat
-Body fat influences onset of puberty. -Most girls must weigh at least 100 pounds before experiencing first period. -Globally, urban children are more often overfed and underexercised than rural children.
Sexual activity
-Boys are more influenced by hormones and girls by culture. -Both are influenced by hormones, society, biology, and culture.
What are the origins of disordered eating
-Cultural image -Stress -Puberty -Hormones -Childhood patters
What is the secular trend?
-Data on puberty over the centuries that reveals a dramatic example of a long-term statistical increase or decrease. -Each generation has experienced puberty a few weeks earlier, and has grown a centimeter or so taller, than did the preceding one. -Secular trend has stopped in developed nations.
Problems less problematic than in earlier decades
-Decreased teen births in every nation -Rise in use of protection -Decrease in teen abortion rate
Child sexual abuse
-Definition -Most common time International and national rates
Define Sexually transmitted infection (STI)
-Disease spread by sexual contact, including syphilis, gonorrhea, genital herpes, chlamydia, and HIV Worldwide, sexually active teenagers have higher rates of most common STIs -Early age of first intercourse, failure to use condoms, and hesitancy to report infection contribute to high U.S. infection rate
Hazards related to adolescent sexual activity
-Earlier puberty and weaker social taboos encourage sex at earlier age -Early sex correlates with depression and drug abuse Increased complexity and expense are related to parenting -More common and dangerous STIs
When does stress arrive?
-Earlier, for example a child's parents are sick or addicted or divorced. -Stress can effect children who are sensitive puberty comes early if their family interaction is stressful but late if their family is supportive Several longitudinal studies show a direct link between stress and early puberty -Makes reproduction more difficult in adulthood and hastens hormonal onset of puberty
Define Bulimia nervosa (Binge-purge syndrome)
-Eating disorder characterized by binge eating and subsequent purging, usually by induced vomiting and/or use of laxatives
Define anorexia nervosa
-Eating disorder characterized by self-starvation -Affected individuals voluntarily under eat and often over exercise, depriving their vital organs of nutrition. -Anorexia can be fatal.
Characteristics of sexual abuse
-Family members most likely to abuse -Victims often isolated and uninformed -Impact of abuse often continues into adulthood
What are the family patterns and eating disorder reduction
-Healthy eating in childhood Eating together during childhood
Several aspects of adolescent brain development are positive
-Increased myleniation, which decreases reaction time -Enhanced dopamine activity, promoting pleasurable experiences -Synaptic growth enhances moral development and openness to new experiences and ideas
Endurance improves what?
-Lungs triple in weight -Heart doubles in size
Organ growth
-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. -Only lymphoid system decreases in size.
Define diet deficiencies
-Many adolescents are deficient in their intake of necessary vitamins or minerals. -Deficiencies include iron, calcium, zinc, and other minerals, since these are needed for bone and muscle growth. -Nutritional deficiencies result from the food choices that young adolescents are allowed, even enticed, to make.
Risk and reward
-Neurological research finds that the reward parts of adolescents' brains are far stronger than inhibition parts. -Slower-maturing prefrontal cortex makes powerful sensations desirable—loud music, speeding cars, strong drugs—compelling. -Teens seek excitement and pleasure, especially the social pleasure of a peer's admiration. -Many types of psychopathology increase at puberty—especially early puberty
Skin system changes what?
-Oilier, sweatier, more prone to acne; growth over face and sex organs
Secondary sex characteristics
-Physical traits that are not directly involved in reproduction but that indicate sexual maturity -Shape -Hair patterns -Breasts
According to the DSM-5, anorexia is officially diagnosed when three symptoms are evident:
-Significantly low body weight for developmental stage (BMI of 17 or lower) Intense fear of weight gain -Disturbed body perception and denial of the problem
Skin and hair
-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 sex organs. In many ways, hair is more than a growth characteristic; it becomes a display of sexuality
Binge-eating disorder
-The DSM-5 introduced binge-eating disorder as a diagnostic category, in part to recognize that bingeing is sometimes associated with anorexia
What is the age of puberty?
Age 11 or 12 is the most likely age of visible onset.
What does menarche mean?
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
Define pituitary
Gland in the brain that responds to a signal from the hypothalamus by producing many hormones, including those that regulate growth and control other glands, among them the adrenal and sex glands.
_____________ and the ____________ regulate the hormones that affect the biorhythms of stress, appetite, sleep, and so on.
Hypothalamus; pituitary
__________ and _________ areas develop before the reflective ones do.
Instinctual and emotional
Lymphoid system decreases in size
Less susceptibility to respiratory ailments
__________ matures before the prefrontal cortex (planning ahead, emotional regulation).
Limbic system
__________ and __________ maturation occur in sequence, proceeding from the inner brain to the cortex and from back to front
Myelination and maturation
What are hormones?
Organic chemical substance that is produced by one body tissue and conveyed via the bloodstream to another to affect some physiological function
Define gonads
Paired sex glands (ovaries in females, testicles in males) Gonads produce hormones and gametes
Primary sex characteristics
Parts of the body that are directly involved in reproduction, including the vagina, uterus, ovaries, testicles, and penis
Define body image
Person's idea of how his or her body looks
__________ puberty (sexual development before age 8) occurs about once in 5,000 children, for unknown reasons.
Precocious
Define HPA (hypothalamus-pituitary-adrenal) axis
Sequence of a chain reaction of hormone production, originating in the hypothalamus and moving to the pituitary and then to the adrenal glands
Define HPG (hypothalamus-pituitary-gonad) axis
Sequence of hormone production that originates in the hypothalamus, moves to the pituitary, and then to the gonads
Define Estradiol
Sex hormone, considered the chief estrogen. Females produce more estradiol than males do
Define Testosterone
Sex hormone, the best known of the androgens (male hormones). Secreted in far greater amounts by males than by females
Define growth spurt
The relatively sudden and rapid physical growth that occurs during puberty.
What is puberty?
Time between the first onrush of hormones and full adult physical development usually lasting three to five years. Requires many more years to achieve psychosocial maturity
True or false Each body part increases in size on a schedule; growth is not always symmetrical.
True
True or false Weight usually precedes height, and growth of the limbs precedes growth of the torso.
True
True or false Only lymphoid system (which includes the tonsils and adenoids), decreases in size--teenagers are less susceptible to respiratory ailments.
True
True or false: 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. Size and maturation are important for many adolescents in every nation.
True
True or false: Early-maturing girls tend to have lower self-esteem, more depression, and poorer body image than later-maturing girls. Early-maturing girls may be attracted to older boyfriends and enter into abusive relationships more often than other girls.
True
Define adrenal glands?
Two glands, located above the kidneys, that produce hormones including the "stress hormones" epinephrine (adrenaline) and norepinephrine
Instinctual and emotional areas
When emotions are intense, especially when one is with peers, the logical part of the brain shuts down. When stress, arousal, passion, sensory bombardment, drug intoxication, or deprivation is extreme, the adolescent brain is overtaken by impulses that might shame adults.
Body image with girls
diet partly because boys tend to prefer to date thin girls.
Gherkin is known as what?
hungry
Body image with boys
want to look taller and stronger partly because girls value well-developed muscles in males.
