Body, Brain & Health Development PDF

Chapter 5: Body, Brain & Health September 30, 2024 Brain Development in Children The cerebral cortex is divided into two separate halves, called cerebral hemispheres communicate through a dense tract of fibers, the corpus callosum Thickens as the brain matures...

Chapter 5: Body, Brain & Health September 30, 2024 Brain Development in Children The cerebral cortex is divided into two separate halves, called cerebral hemispheres communicate through a dense tract of fibers, the corpus callosum Thickens as the brain matures Cerebral lateralization - the two hemispheres are specialized for different modes of processing Lateralization is evident at birth Physical Behavior in Toddlers and Children Toddlers Capable of controlling their movements in relation to a stationary world Children Master the ability to move capably in a changing environment Some sex differences in physical development and strength emerge during this period Due at least in part to nurture Example: “You throw like a girl.” --Even as toddlers, boys are encouraged to play with/throw balls more often than girls are Childhood Health and Wellness Accidents are the leading cause of death throughout the childhood years Nutrition is a major concern Children consume 27% of calories from snacks on average High calorie foods that lack nutritive value are often available cheaply Children who do not have easy access to junk foods in their neighborhoods tend to consume less of it Physical Activity 60 minutes of physical activity a day is recommended Children watch on average 25 hours of TV per week, concerns over neighborhood safety may limit outdoor play opportunities for low SES kids Physical activity lowers risk of obesity and related diseases, can also support brain development Questions about body/brain/health development throughout childhood? Adolescent Brain Development Volume of gray matter (made up of cell bodies) increases, peaks, and then decreases throughout the teen years Associated with increased synaptogenesis just before puberty Volume of white matter (consisting of clusters of axons), increases linearly throughout development Brain Maturation Image from brainfacts.org; adapted from Gogtay, et al., 2004 Adolescent Brain Development Adolescents are more likely to engage in risk taking Due to mature reward system + immature frontal lobes (involved in self-control and abstract thinking) Teens at risk for alcohol consumption and binge drinking More likely to take other risks (smoking, risky sexual behaviors) under the influence of alcohol. Display poor judgment and decision-making  The Endocrine System Pituitary gland Most important gland of the brain Controlled by the hypothalamus Triggers release of hormones from all other endocrine glands Produces growth hormone Thyroid Gland Thyroid deficiency during pregnancy/infancy brain development, intellectual ability The Endocrine System Plays a role in regulating male and female hormones Testosterone, androgens Estrogen, progesterone Stimulate production of growth hormone → physical maturation Adolescent growth spurt Development of muscles and bones Development of sex organs Sexual motivation Hormonal Influences on Growth & Development Triggered by increased production of growth hormones during adolescence Gender Height Weight Female 12 years 12.5 years Male 13.4 years 13.9 years Adolescent Sexual Maturation Adrenarche Tanner Scale Circulation of adrenal hormones Contributes to secondary sex characteristics as pubic and axillary (underarm) hair Menarche First menstruation typically between ages 11 and 15 Semenarche Boy’s first ejaculation around age 13 Adolescent Sexual Maturation Adolescent Attitudes towards Sexual Maturation Females Girls experiencing puberty tend to become self-conscious about their physical appearance 23% of girls view menarche positively Being overweight during early childhood (birth to 2 years) is associated with early puberty among girls Girls who are severely underweight may begin menstruating late or stop menstruating after they have begun Early-maturing girls have a greater likelihood of experiencing long- term adjustment problems, including anxiety and depression Later-developing girls outperform other students Adolescent Attitudes towards Sexual Maturation Males Boys are more likely to welcome their weight gain and voice changes 62% of boys regard semenarche positively Later-developing boys tend to perform poorly on school achievement tests Adolescent Attitudes towards Sexual Maturation The physical and hormonal changes of puberty do not directly cause straightforward psychological changes in the adolescent. Rather, biological changes interact with adolescents’ psychological characteristics and changes in the social environment to influence how adolescence is experienced. Questions about what we’ve learned about adolescent development so far? Adolescent Health and Wellness Environmental factors Health risks associated with contributing to the obesity obesity: epidemic: Heart and kidney disease Inactive lifestyles Diabetes Portion sizes Liver problems Fat content Arthritis Sugar content Life stress Metabolic syndrome (MeTS) Poverty Affects brain function and can result in cognitive deficits Adolescent Health and Wellness: Exercise Less than one in five teenagers do the recommended 60 minutes of daily physical activity Obesity rates have increased from 10% to 15% over a 12-year period Adolescent Health and Wellness: Sleep Recommended amount of sleep for adolescents is 8-9 hours About 80% of teens do not get enough sleep Traumatic Brain Injury (TBI) Concussion – brief loss of brain function due to a hit or blow to the head. Dramatic increase in teens treated in the ER for concussions over the past decade. Sports-related concussions most commonly occur in American football, boxing, ice hockey, rugby, and soccer Military veterans exposed to combat Immediate symptoms Headache Sensitivity to light and sound Feeling dizzy or foggy Slowed reaction time Insufficient recovery time after a TBI can leave the brain more vulnerable to subsequent trauma Chronic Traumatic Encephalopathy (CTE) A progressive degenerative brain disease that occurs as a consequence of repetitive mild TBI Symptoms: irritability, impulsivity, aggression, depression, short-term memory loss and heightened suicidality Symptoms typically begin 8–10 years after experiencing repetitive mild TBI Neuropathological changes: Generalized atrophy of the cerebral cortex Enlarged ventricles Extensive p-tau-immunoreactive neurofibrillary tangles Degeneration of axons and white matter fiber bundles Chronic Traumatic Encephalopathy (CTE) McKee et al. (2017): 110 of 111 (99%) former NFL players tested positive for CTE Among those with mild CTE, 96% had behavioral and/or mood symptoms, 85% had cognitive symptoms, and 33% had signs of dementia. The most common cause of death was suicide (27%) Among those with severe CTE, 89% had behavioral or mood symptoms or both, 95% had cognitive symptoms, and 85% had signs of dementia. The most common cause of death was neurodegenerative (ie, dementia- related and parkinsonian-related causes of death) (47%) Recent evidence for CTE even in younger- aged non-professional athletes CTE has been reported in people as young as age 17 152 brains (141 male, 11 female) of people aged 30 years or younger at death who had a history of repeated head impact from playing contact sports were analyzed More than 40% of the brains had CTE Most cases were mild People who donated brains with evidence of CTE were also found to have cognitive, behavioral, and mood symptoms at a higher rate than their non-CTE counterparts McKee et al., 2023 Questions about body/brain/health development throughout adolescence? Theories of Aging Programmed theories of aging Emphasize the systematic genetic control of aging processes Random error theories of aging Call attention to more haphazard processes that cause errors in cells to accumulate and organ systems to deteriorate Reproductive System in Adulthood Females: Genital organ change begins in the 40s Transition – perimenopause Changes in reproductive organs and sexual functioning Menopause Ethnic differences in the severity of symptoms Hormone Replacement Therapy to treat menopause symptoms can be effective (but is controversial). Males: Unlike menopause, no event to mark reproductive changes Decline in testosterone levels 30% decrease in sperm production between 30 and 60 Prostate cancer rates rise in middle adulthood Hormonal Changes in Adulthood Males- testosterone levels fluctuate annually (highest in spring) and daily (highest in morning) Women- hormones shift each month as a woman moved through her cycle Premenstrual Syndrome: bloating, headache, moodiness, breast tenderness in days just before start of menstruation. Estimates vary widely, but best guess is that ~50% of women experience PMS. Likely caused by fluctuations in estrogen and progesterone levels. Premenstrual Dysphoric Disorder: occurs in about 2-3% of women. Includes affective symptoms in addition to the physical symptoms associated with menstruation. Interferes with planned activities and daily life. Autonomic Nervous System Changes in Old Age Difficulty Regulating Body Temperature Elderly require an environment that provides external means of temperature regulation. Difficulty Sleeping Nearly every aspect of sleep undergoes age-related changes Including changes in circadian rhythm changes Good sleep is important for maintaining overall good physical and mental health. Physical Changes Typical in Adulthood Changes in appearance and functioning start to become evident during middle adulthood Aerobic capacity and other physiological measurements vary widely among 70-year-olds Body Build also changes: Decrease in height Initial weight gain followed by weight loss Muscle deterioration leads to reduced strength National Senior Games