Developmental psychology/Chapter 12/Growing Older

Although adults are the most economically productive individuals, they experience senescene - when adulthood begins, so does the slow processing of all of the organs.
 * Breathing - Adults may have to take in more air due to homeostasis, explaining why a 40-year-old man isn't usually as fit as a 20-year-old man. This effect may be reduced by regular exercise and avoiding smoking, which may cause chronic obstructive pulmonary disease (COPD). Eating right, sleeping well, and other similar decisions impact one's physique.
 * The Brain - The brain slows down: fewer neurons, neurons fire slowly, less myelination, reaction time increases as dendrites aren't as effective. On the opposite hand, nodes and new dendrites grow as more experiences are reviewed. Before age 65, one of five brain injuries (or multiple) may take place:
 * Traumatic brain injury (TBI) - May result from accidents, injuries, or sports. Happens in adults <30yrs. Reduce brain function.
 * Viruses - The blood-brain barrier, the "wall" that protects brains from most illnesses, may be penetrated by certain viruses, such as HIV.
 * Genes - 1/1k people inherit an Alzheimer gene, where implications of it usually show after age 40.
 * Substance Abuse - Wernicke-Korsakoff syndrome derives from substance abuse, specifically alcoholic abuse. Implications show after age 40.
 * Poor circulation - Any item that hinders blood flow through the brain, such as smoking, harms thinking; seen by age 50.

Surprisingly, brains can actually grow despite the "stereotype". Experiences strengthen cognitive understanding of the world and link throughout the brain. The hippocampus actually gains brain cells, specifically in the dentate gyrus. Plasticity is evident in this growth. Although the adult brain may be a bit slower, they are definitely wiser through their handfuls of experiences. Albeit a generally disputed discussion, brain growth is evident in adults.
 * The Senses - The senses decrease over time but can be compensated by the brain (using other senses to compensate), behavior (seeing someone talk --> improves the ability to hear and follow through), and technology (glasses/contact lenses).
 * Many visual changes take place. The peripheral (side) vision weakens before the frontal (front) vision; certain colors fade; takes longer to adjust to bright and dark; vision goes from nearsighted [shape of the eye's lens is too curved] (see close better) to farsight (see far better).
 * In terms of hearing, it diminishes as one grows - but we barely will notice it since hearing is already a limited sense. Presbycusis isn't diagnosed until much later. Again, it depends on the person. For example, musicians can detect different pitches better than a non-musician.
 * One's appearance also takes a change. This can include weaker/thinner hair, becoming shorter, wrinkles and just generally appearing old. Skins become drier/rough after age 20 and women are noticeable with rougher skin after age 50 - due to a lack of estrogen. Hair is also lost, with women having thinner hair while men just straight up lose it. Although not detrimental to physical health, it can lead to depression. One's body and shape changes as they are less agile and flexible. They may even become shorter as back muscles/tissues lose density, leading to a smaller spine.
 * Lastly, how does one's sexual reproductive system respond to aging? Variability. Some are happy, some are not with their sex lives.
 * Infertility - After trying for a year and you're unable to conceive a child, you're infertile. The "inability to have a second child after five years of trying" is second infertility. Infertility affects both men and women. Both are affected by anything that impairs physical ability, such as alcohol, weed, and even excessive stress. Some women get pelvic inflammatory disease (PID), preventing sperm from reaching the ovum. Surgery and assisted reproductive technology (ART) triumph over some of these issues. A marriage counselor may be recommended when dealing with ARTs to ensure happy communication between both parties.
 * Women may go through a menopause at middle-age, because of a drop in hormones and they may experience their last period. Usually, it's 12 months after a woman's last period and is met with either barely noticeable or irritating side effects, such as vaginal dryness, sweatiness, and a reduced sex drive. Men go something a bit similar, but experience a reduced sex drive out of a psychological, not physiological, cause. Hormone replacement theory (HRT) is taken by post-menopause women and some men to produce hormones to compensate for the loss/to prevent diseases, such as bone fragility [but may cause the opposite]. The risk of breast cancer for women is a confirmed side effect for HRT. It could reduce bone fragility and actually improve hearing, but the risks need to be weighed - it may be best for younger women to take it vs. older women. For men, less depressive effects and increased sexual drive may result from HRT, but, like women, they have their own ranges of negative side effects to take into account for.