Secular growth trend is the relative increase in height over time due to access to betternutrition; which is why younger generations tend to be taller than older generations.They also reach puberty faster. Puberty is characterized by the adolescent growth spurt, theproduction of sex cells (menarche and spermarche) and development of secondary sexcharacteristics (facial hair, breasts, etc.)Hormones are produced by different glands and they regulate bodily functions.● Human growth hormone is made in the pituitary gland and it regulates muscular andskeletal growth. Growth happens at night in an irregular manner (80% of growth happenson 20% of days)● Thyroxine is produced by the thyroid and it helps with brain and neural development● Adrenaline is made by the adrenal gland● Testosterone is made by the testes, and it leads to facial hair, muscular development● Estrogen is made by the ovaries and it leads to breasts and female development● Melatonin (detailed below) is linked to sleep, and it is produced by the pineal glandduring the night. It is based on light, hence why dark rooms let us fall asleep during theday and bright rooms prevent us from falling asleep at nightInstrumental traits (aggressiveness, dominance, strong task focus, etc.) are linked totestosteroneExpressive traits (social, nurturing, talkative, etc.) are linked to estrogen____Sleep helps set our biological clock (which is regulated by the suprachiasmatic nucleus) andour circadian rhythm. The suprachiasmatic nucleus is affected by light, which makes senseEEG machines have let us identify 4 main stages of sleep:1. N1 stage, with the myoclonic jerks (muscular twitches due to brain letting go ofvoluntary motor cortex)2. N2 stage, with the beginnings of k complexes3. N3 stage, aka “deep sleep”4. REM, aka “rapid-eye movement,” when it looks like the person is awake because theireyes are movingThere are a few different types of brain waves.● Alpha waves are smaller waves that begin before N1● During N1, they turn into theta waves which are longer.● Alpha waves, theta waves and k complexes (massive electrical spikes) occur during N2● K complexes occur more during N3, along with delta wavesDyssomnias are sleep disorders, and they can include● Insomnia● Hypersomnia (sleep too much)● Narcolepsy (fall asleep in quick episodes)Parasomnias are strange behaviors that occur while we’re already asleep, and they include● Nightmares (in REM)● Night terrors (in Stage N3)● Sleepwalking / sleep talking (also in N3)● Sleep paralysisThere are 4 primary states babies can be in1. Sleeping2. Awake Activity (learning)3. Feeding (connected to growth)4. Crying (2-3 hours a day)a. Basic cry: soft first, more insistent later (something isn’t right)b. Mad cry: sudden onset, rapid conclusion (something taken away)c. Pain cry: extremely loud, essentially screaming (in pain)Rocking, stroking and singing all help. 45% less crying if we held them more. Swaddling(wrapping baby tightly in blankets) also really helps.The main source of nutrition for babies is breast milk which is high in nutrition, but it also leadsto less upset stomachs, higher disease immunity and greater acceptance of a variety of foods.Breast milk cannot be contaminated! Unlike formula, which often needs to be contaminated withwater and that water might be contaminated in third-world countriesWe have to wean them off eventually at 3-6 months so they can eat solid foods, and when wedo, we need to introduce enough calcium so their bones (which are initially cartilage) can ossifyIf we don’t get enough calcium, we have osteoporosis aka “brittle bones.” There are 10 millionAmerican cases every year, 80% of which are in women over 50. However, it can be preventedby consuming 1300 mg of calcium a day, and it can also be prevented by exercising.We also need iron or we will get permanent brain damage. We get it from broccoli, brusselsprouts, etc. and it’s also absorbed via Vitamin C so we need that too._____Obesity = at least 20% over body weight. 26% of Americans are obese. Causes:● Poor nutrition● Lack of exercise● However, many babies are also born obese. This is due to 1) mothers and fathers beingobese, which is a risk factor, but also 2) more c-sections taking place, which allows forchildren who were normally too big to be born.● Greater screen time (correlated with sleeping less, which is correlated with beinghungrier the next day and gaining weight)● The sugar from non-nutritious things (like Happy Meals) can lead to a chemicalimbalance and make us feel like we’re starvingWe have to be careful, though: implementing diets too early or too suddenly can lead to greaterweight gain. Lower portions can kill our metabolism. Ironically, dieting doesn’t workBulimia and anorexia are both developing due to social standards and social media. Adolescentgirls develop it 10 times more than adolescent boys; and while it normally occurs most in younggirls, in the US, it actually occurs most in university women. Speaking of which, it happensprimarily in western nations overallBulimia and anorexia are usually granting a sense of controlKids only need 1500-1700 calories a day, and adults need 2000 a day, but we eat so muchmore than that!Malnutrition is defined as being small for one’s age AND/OR not having the proper nutritions. Itis possible to be obese and malnourished.● 1 in 3 American kids are malnourished● Often tied to being absent in school● 20% of American kids have an iron or iodine deficiency (which is tied to brain growth aswell as muscular growth)11 million kids die each year from diseases that are totally preventable (malaria, pneumonia,diarrhea, etc.) by vaccines, nutrition, and changing habits.At the same time, we want some diseases to be caught on by children: Shingles, Chicken Pox,and