H.D - Chapter 9 Flashcards
Theories of Aging
Programmed Theories
Follow a biological timetable, possibly a continuation of childhood development
EX: Changes in gene expression that affect the systems responsible for maintenance, repair, and defense responses
Theories of Aging
Damage or Error Theories
Emphasis environmental factors that cause cumulative damage in organisms
Theories of Aging
Genes
-Some promote long life, others limit it
-Researches believe its a combination of many genes
EX: genes that help fight disease, accelerate /. decrease rate of aging `
Theories of Aging
Evolutionary Theory
Natural selection
EX: Genes for Alzheimer’s disease have not been eliminated yet
Theories of Aging
Cellular Clock Theory
Normal Cells cannot divide indefinitely
EX: Telomere
Telomere
At the end of each chromosome strand is a sequence of DNA that does not code for any particular protein, but protects the rest of the chromosome
Each replication gets shorter
Cellular Senescence:
Stop replicating by turning itself off
-Not dead, still interact w other cells and create diseases
Apoptosis:
Stop replicating by dying
Cancer:
Continue to divide and become abnormal
Theories of Aging
DNA Damage
-Some cannot be repaired and remains in DNA
-Can cause cells to deteriorate and malfunction
EX: Ultraviolet radiation, cigarette smoking
Theories of Aging
Mitochondrial damage
Mitochondria:
Cell organelle that uses oxygen to procure energy ATP from food
Can become less efficient and make cell die
Theories of Aging
Free Radicals
Missing an electron and create instability in surrounding molecules by taking electrons from them
-Most part cause damage in cells and tissues
-Identified w disorders associated a advanced age (cancer, cataracts)
Theories of Aging
Immune and Hormonal Stress Theories
-Metabolic stress:
Life sustaining activities of the body, also create biological stress
-Innate Immune system:
Cells lose ability to communicate good w age
-Adaptive Immune System:
Tcells (lymphocytes; fight freight threats)
Older adults, less able to produce T cells
Theories of Aging
Hormonal Stress Theory
As we age the ability of the hypothalamus to regulate hormones in the Boyd begins to decline leading to metabolic problems
Associated w excess of stress hormone cortisol
Working Memory
Phonological loop:
Maintains information about auditory stimuli
Older adults perform same as young adults
Visuospatial Sketchpad:
Maintains information about visual stimuli
Mental Executive:
Overseas working memory, allocating resources where needed and monitoring whether cognitive strategies are being effective
Mostly negatively impacted by age
Old and Young people on memory tasks
-In tasks that require distributed attention between different stimuli, older people do worse
-Young adults:
Learned and performed each task w/o any loss of speed and efficiency
Took some practice
Older adults:
Could perform well if did each task individually
-Recognition –> same as old and young
-Recall –> older memory deficits
Divided Attention
-Older adults less likely to ignore distractions
-Given more time, could perform same as younger
-Greater difficulty shifting attention
-More likely to process meaningful information
(cross sectional designs, greater decline than longitudinal studies)
Study comparing young and old adults on easy and complex tasks
-Activate larger regions of their attentional and executive networks when complex tasks
