Transcript Adolescence
ADOLESCENCE – PHYSICAL DEVELOPMENT OT 500 Spring 2016 WHAT IS ADOLESCENCE? Transitional period between childhood and adulthood G. Stanley Hall Proposed adolescence as separate stage: turmoil Marked by Sturm (storm) and Drang (stress) Conflict between independence and dependence Sigmund Freud Anna Freud Genital stage: puberity; sexual impulses Turbulent period Current theorists Reorganization of biological, cognitive, social and emotional functioning; not necessarily turbulent or stressful WHAT IS ADOLESCENCE? Three Phases of Adolescence Early adolescence (11 or 12 – 14 years) Middle adolescence (14 – 16 years) Late adolescence (16 – 18 or 19 years) Tweens Earlier age for adolescence Emerging Adulthood Later age for adolescence WHAT IS PUBERTY? Puberty is a biological concept Puberty is controlled by a complex feedback loop Attaining sexual maturity and the ability to reproduce Hypothalamus – Pituitary gland – Gonads – Hormones which further stimulate the hypothalamus Sex hormones trigger development of Primary sex characteristics that make reproduction possible: ovaries, vagina, uterus, and fallopian tubes in women; in males, penis, testes, prostate gland, and seminal vesicles Secondary sex characteristics: in women, breast development, pubic, under arm hair; males, deepening of the voice, facial, pubic, underarm hair WHAT HAPPENS DURING THE ADOLESCENT GROWTH SPURT? Girls begin their growth spurt earlier than boys; around 10-11 for girls, and 12-14 for boys Reach peak growth in height about 2 years after spurt began Continue to grow at a slower rate for another 2 years Weight spurt begins about 18 months after height spurt Boys catch up to girls and eventually are taller and heavier Body shapes differ by sex/gender Boys have broader shoulders Girls gain almost twice as much fatty tissue Boys average 4 inches in their growth spurt while girls average about 3 inches INDIVIDUAL DIFFERENCES SPURTS IN GROWTH Figure 14.1 WHAT HAPPENS DURING THE ADOLESCENT GROWTH SPURT? Asynchronous Growth (Lanky; awkward; gawky) Exception to proximodistal growth Hands and feet mature before arms and legs Reversal of cephalocaudal growth Legs reach peak growth before shoulders and chest Secular Trend: are we still growing taller than our parents?? May have reached genetic potential In industrialized countries Middle-upper-class families – stopped growing taller Poorer families continue to make gains Nutrition and health care are factors PUBERTAL CHANGES IN BOYS Average age of 11½ – first visible sign of puberty Body hair growth Voice deepens – growth of larynx; lengthening of vocal cords Acne Increase in penile erections Growth of testes accelerates testosterone production Nocturnal emissions Gynecomastia – enlargement of breasts About age 20 to 21 – puberty ends Epiphyseal closure of bones PUBERTAL CHANGES IN GIRLS Increased estrogen production Stimulates breast buds (mammary glands do not mature fully until a women has a baby) Promotes fatty tissue in hips and buttocks Production of androgen Estrogen causes labia, vagina, and uterus to develop Androgens cause clitoris to develop Menarche (first menstruation) May begin as early as 9 or as late as 16 Body weight may trigger menarche Hormonal Regulation of Menstrual Cycle Ovulate 12 to 18 months after menarche Simulates pubic and underarm hair growth Average menstrual cycle is 28 days May be irregular during first 2 years Psychological Impact of Menarche Rite of passage; Educated and prepared – more positive THE DECLINE IN AGE AT MENARCHE Figure 14.4 WHAT ARE THE EFFECTS OF EARLY OR LATE MATURATION ON ADOLESCENTS Boys Early maturation – more positive effects Popular, more poised, heightened self-worth May have some negative effects like increased expectations and demands (exceeding ability) Late maturation Not rushed into maturity May feel dominated by early-maturing boys May be teased or bullied; feel insecure Lower-income – early maturation is greatest benefit Value physical prowess WHAT ARE THE EFFECTS OF EARLY OR LATE MATURATION ON ADOLESCENTS Girls Girls have more negative body image, which may increase risk of feelings of depression Early maturation – tends to have more negative effects Negative body image Feel awkward and conspicuous More problems in school and emotional issues Preoccupied with body weight By late adolescence body dissatisfaction declines WHAT BRAIN DEVELOPMENT TAKE PLACE DURING ADOLESCENCE? Increase in gray matter Gains in thickness of cerebral cortex based on learning – sensory and motor activities’ prefrontal cortex and executive functions Executive functioning improves Emotional sensitivity declines with myelination of the frontal lob Synaptic pruning “Use it or lose it” Genes and environment play role in shaping the brain Importance of cerebellum, amygdala, and prefrontal cortex Brain vunerabilities; early signs of schizophrenia begin to appear often in late adolescence SEE www.ted.com/talks/sarah_jayne_blakemore_the_mysterious_workin gs_of_the_adolescent_brain?language=en WHAT HAPPENS TO THE BRAIN WHEN AN ADOLESCENT PRACTICES PIANO SEVERAL HOURS A DAY? Figure 14.5 HEALTH IN ADOLESCENCE WHAT KINDS OF SEXUALLY TRANSMITTED INFECTIONS ARE THERE? Bacterial infections Chlamydia Most common STI in adolescents Major cause of pelvic inflammatory disease Gonorrhea and syphilis Viral infections HIV/AIDS, genital herpes Genital warts caused by HPV Linked to cervical cancer Vaccine HIV/AIDS Left untreated – lethal Risk factors for HIV/AIDS Young gay males Homeless and runaway youths Injecting drugs Women and HIV/AIDS Minority of cases in US Europe, Africa, SE Asia – sexually active teenage girls have higher rates than older women or young men WHAT FACTORS PLACE ADOLESCENTS AT RISK FOR CONTRACTING STIS? Sexual activity Sex with multiple partners Failure to use condoms Drug abuse PREVENTION Education Strategies; Increased knowledge about STIs; access to condoms? clean needles?? Enhance teens’ sense of control Effective decision making and social skills HOW HEALTHY ARE AMERICAN ADOLESCENTS? Most American adolescents are healthy May be less healthy than their parents at the same age Lifestyle factors and risky behaviors Death rates for males is twice as great as females Males more likely to take risks that end in accidents, suicide, or homicide Accidents 60% of teen deaths Most involve motor vehicles Alcohol is frequently implicated in accidental deaths Homicide More frequent for poor and in urban areas Greatest among African American adolescents HOW MUCH SLEEP DO ADOLESCENTS NEED? Need 8.5 to 9.25 hours of sleep per night Sleep deprivation 6 or fewer hours per night Reasons for insufficient sleep Hectic schedules and commitments Brain development – phase delay WHAT ARE THE NUTRITIONAL NEEDS OF ADOLESCENTS? Rapid growth Average girl – 1,800 to 2,400 calories Average boy – 2,200 to 3,200 calories Need for calcium – bone growth Females need to build up bone density and prevent osteoporosis Nutritional deficits Irregular eating habits Fast food or junk food WHAT ARE EATING DISORDERS? Gross disturbances in eating patterns Anorexia Nervosa Weigh less than 85% of desirable body weight More frequent in females than males Severe weight loss impacts general health 4 to 5% mortality rate Bulimia Nervosa Characterized by recurrent cycles of binge eating and purging Tend to be perfectionistic about body WHAT ARE THE ORIGINS OF EATING DISORDERS? Psychoanalytic perspective Family control issues Child abuse, sexual abuse are risk factors Societal slender social ideal Anorexia is an effort to regress to prepubescence Demands of athletics and activities Genetic TREATMENT: May require hospitalization and nasogastric (tube) feeding Antidepressants Family therapy Cognitive-behavioral therapy WHAT IS SUBSTANCE ABUSE? WHAT IS SUBSTANCE DEPENDENCE? Substance abuse Ongoing use of a substance despite the problems it causes Substance dependence No control over substance Tolerance – body becomes habituated to substance Abstinence syndrome – withdrawal symptoms WHAT ARE THE EFFECTS OF DEPRESSANTS? Slows the activity of the nervous system Alcohol Lowers inhibitions Intoxicant Long-term drinking may produce serious physical disorders Heroin Provides an euphoric “rush” Barbiturates Legitimate medical uses Used illegally to produce a mild euphoria WHAT ARE THE EFFECTS OF STIMULANTS? Speed up heart beat and other bodily functions Nicotine Raises rate of burning calories, lowers appetite Addictive stimulant in tobacco Cocaine Euphoria, boosts self-confidence, reduces appetite Amphetamines Used to stay awake or reduce appetite High doses cause restlessness, insomnia, irritability WHAT ARE THE EFFECTS OF HALLUCINOGENICS? Bring on perceptual distortions or hallucinations Marijuana Used to relax and elevate mood Impairs perceptual-motor coordination Interferes with short-term memory and learning Ecstasy (MDMA) Feelings of elation and self-confidence Lowers inhibitions and increases risky behaviors LSD Impairs coordination and judgment Hallucinations and paranoid delusions HOW WIDESPREAD IS SUBSTANCE ABUSE? Illicit drug use by 8th- to 12th-grade students has declined Incidence of alcohol, cigarettes, and marijuana is relatively high Occasional death from alcohol overdose Connected with reckless behaviors Less than 2% high school students use steroids Used to build muscle mass More adolescents disapprove of regular drug use than experimental drug use WHAT FACTORS ARE ASSOCIATED WITH SUBSTANCE ABUSE AND DEPENDENCE? Experimental use Peer pressure, acceptance by peers Rebelling against moral or social constraints Curiosity Escape from boredom Imitating parents or adults Social Cognitive Theory Someone has recommended them or they have observed someone using them Continued use depends on reinforcement WHAT FACTORS ARE ASSOCIATED WITH SUBSTANCE ABUSE AND DEPENDENCE? Predictors of drug use and abuse Association with peers who use or tolerate drugs Parental communication discourages drug use School problems Biological factors Difficult to treat Often doesn’t want to stop Relapse problems Need to address other disorders and family dysfunctions