HDFS 2317 1st Edition Lecture 63 - Physical Development and Biological AgingOutline of Previous LectureI. Epigenetics Video 1 (NOVA ScienceNow)II. Epigenetic Video 2III. QuestionsOutline of Current Lecture I. Body Growth and ChangeII. The BrainIII. LongevityCurrent LectureI. Body Growth and Changea. Patterns of growthi. Cephalocaudal pattern - physical growth in size, weight, and in feature differentiation from top to bottomii. Proximodistal pattern - growth in control that starts from the outside to the extremitiesiii. Growth rate affected by 1. Socioeconomic status2. Birth order3. Maternal habits of your mother before you were borniv. Growth hormone deficiency - pituitary gland (helps to control growth)b. Look at Figure 3.1 - changes in proportions of the human body during growthc. Look at table of height and weight in infancy and childhoodd. Pubertyi. Period of rapid physical and hormonal changes ii. Physical changes; growth spurt1. Girls - Menarche, hips widen, body haira. Onset for most: 9-15 years of age2. Boys - First ejaculation, grow taller, body haira. Onset for most: 10-17 years of ageiii. Hormonal changes 1. Powerful chemicals from endocrine glands2. Hypothalamus - eating and sexual behaviorThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.3. Pituitary gland - controls growth, regulates glands4. Gonads - male testes, female ovaries5. Gonadotropins - stimulate testes, ovariesiv. Hormones increase dramatically in adolescence1. Testosterone - voice change, genital growtha. Dominates male changes2. Estradiol - estrogen for breast growtha. Dominates female changesv. Onset affects social competencevi. Behaviors and moods can affect hormonesvii. Psychological effects of puberty, onset timing1. Early maturationa. Boys: Positive self-image, better peer relationsb. Girls: Similar to boys, not as strong, at more risk for behavior problems2. Late maturationa. Boys: Developed stronger positive image in their early 340se. Early adulthoodi. Height is constantii. Many reach peak of muscle tone and strength in late teens and twentiesiii. Peak in joint functions in twenties iv. Decline in the thirtiesf. Middle adulthood i. Physical appearance1. Loss of height (more for women), weight gain2. Skin wrinkles, sagging, aging spots appear in 40s or 50s3. Hair thins and graysm fingernails and toenails thicken4. Youth-oriented culture affects lifestyle changes ii. Strength, joints, and bones1. Sarcopenia - muscle mass and strength loss2. 1% to 2% muscle loss after age 50iii. Cardiovascular system and lungs1. HDL and LDL cholesterol, clogged arteries2. Hypertension: blood pressure increases3. Decreased lung capacity after age 55.iv. Sexuality changes1. Climacteric - fertility declines2. Menopause - menstrual periods ceasesa. Dramatic decline of estrogen; a negative experience for most womenv. Males do not lose fertilityvi. Look at Figure 3.4 - Lung capacity, smoking, and ageg. Late adulthoodi. Physical appearance more pronounced 1. Facial wrinkles, age spots2. Weight loss after age 60; decreased by exercise and weight liftingii. Circulatory system1. Increased blood pressure, linked to chronic conditions and longevityII. The Braina. Brain physiologyi. Structure and function1. Forebrain2. Cerebral cortex, has four lobesa. Frontal, occipital, temporal, parietals lobes3. Deeper in braina. Hypothalamus, pituitary gland, amygdala, hippocampus4. Look at Figure 3.6 - The Brain’s Four Lobesii. Neurons: nerve cells handling information processing at the cellular leveliii. Look at Figure 3.7 - The Neuroniv. Lateralization: specialization of functions in one hemisphere of cerebral cortexb. Functions and Lobes of the Cortexi. Frontal - voluntary movement, thinking, personality, intentionalityii. Occipital - visioniii. Parietal - Spatial location, attention, motor controliv. Temporal - hearing, language, information processing, and memoryc. Infancyi. Shaken Baby Syndromeii. Born with about 100 billion neuronsiii. Brain flexibility and resilience demonstrated in deprived environmentsiv. Dramatic increases of neural connectionsv. Brain areas do not mature uniformly; skills affected by myelination and interconnectionsvi. Myelination; visual and auditoryvii. Rapid growth of myelin sheath, dendrite and synapse connectionsviii. Blooming and pruning of connections in brain ix. At birth, greater activity in left hemispherex. Motor control begins about 2 monthsxi. Neglect in infancy and early childhoodd. Childhood i. The brain and head grow more rapidly than any other part of the bodyii. Ages 3-6; most rapid growth in frontal lobeiii. Ages 6 to puberty; most dramatic growth in temporal and parietal lobesiv. Brain pathways and circuitry promote cognitive control (attention, thoughts, actions, choices)e. Adolescencei. Brain continues growth1. Corpus callosum - axon fibers start to thicken2. Prefrontal cortex - increased ability to reason or make decisions aswell as have self control3. Amygdala - emotions, mature earlier than prefrontal cortexf. Adulthood and agingi. Brain loss: 5-10% of weight in ages 20-90ii. Dendrites decrease; myelin sheath damageiii. Shrinkage is not uniform; most in prefrontal cortexiv. General slowing of brain and spinal cord functiong. The adapting braini. Exercise and activities influence development ii. Remarkable repair capability1. Neurogenesis2. Dendrite growthIII. Longevitya. Life span: Upper boundary of life, maximum number of years an individual can live; about 120 years of ageb. Life expectancy: Number of years that an average person lives up to depending on their age.i. Highest in Japan - 81 yearsii. Racial differences in the U.S.1. Highest for whites - 78 yearsa. White females - 81 years2. Females have higher expectancy than malesa. Begins in mid-30s, gap increases with ageb. Male lifestyle associated with more risks, biological factorsc. Biological theories of agingi. Four major theoriesii. Cellular Clock Theory - every species has a genetic limit to their longevity. Cellular clock is the maximum number of times human cells can divide.iii. Free-Radical Theory - We produce free radicals iv. Mitochondrial Theory - Mitochondria starts to decayv. Hormonal Stress Theory - We age because of hormonal