Ch. 29 Human Development & Aging Flashcards

Flashcards covering the themes of exercise, biological mechanisms of senescence (aging), life expectancy statistics, and clinical death from Chapter 29 notes.

Resistance exercises

Activities that lead to the reduction of accidental injuries.

Endurance exercises

Exercises that result in a reduction in body fat, increased cardiac output, and increased oxygen uptake.

Progeria

A genetic defect with symptoms starting around age $2$, including declining growth rate, muscle/skin flaccidity, and atherosclerosis.

Werner’s syndrome

A genetic defect causing a drastic increase in aging, where senescence begins around age $20$ and death occurs around age $50$.

Replicative senescence

The limit on the number of times somatic cells may divide via mitosis.

Telomere

The protective end of a chromosome that degrades during replicative senescence; its shortening is accelerated by smoking, obesity, stress, and chemical exposure.

Telomerase

An enzyme in stem cells and cancer cells that repairs telomere damage and potentially grants immortality.

DNA damage

Daily occurrences of $10,000 - 100,000$ events that are typically corrected via DNA proofreading.

DNA Damage Sensitivity

Damage is most severe in non-dividing cells such as neurons, skeletal muscle fibers, and cardiomyocytes.

Cross-Linking Theory

A mechanism of senescence where aging is attributed to the cross-linking of collagen, which makes up $\frac{1}{4}$ of body proteins.

Collagen Cross-linking Effects

The process that results in stiff joints, lenses, and arteries during aging.

Life Expectancy

The average length of life in a given population.

Global Life Expectancy ($1950$)

The average length of life worldwide in $1950$, which was $46$ years.

Global Life Expectancy ($2015$)

The average length of life worldwide in $2015$, which was $71$ years.

Life Span

The maximum length of life; while most die before age $100$, the oldest recorded is Jeanne Calment at $122$ years old ($1875-1997$).

Clinical death

The cessation of breathing and blood flow, though the heart may still be beating.

Brain activity cessation

The point at which brain activity stops, occurring approximately $20-40$ seconds after blood flow stops.