Physiology of Aging Flashcards
Define Aging
Gradual loss in reserve capacity of organs and organ systems leading to functional impairment & ultimately to death
Define Homeostasis
Maintaining of the stability of the internal environment
Common Reduced Homeostatic Responses in the Elderly
Baroreceptor responsiveness Thermoregulatory responses Cardiac reserve Thirst Dark adaptation
What does a reduced baroreceptor responsiveness lead to?
Increased postural hypotension
What does a reduced thermoregulatory response lead to?
Higher hypothermia, hyperthermia
What does a reduced cardiac reserve lead to?
Fluid overload
What does reduced thirst lead to?
Dehydration
What does a reduced dark adaptation lead to?
Night driving hazards
Host Defense Against Infection
Skin, mucous membranes Mucociliary defenses Gastric BPH Absence of fever PMN's altered, t-cells altered
Most Common Early Sign of Aging
Difficulty staying up all night & working the next day
Early Signs of Aging in the 30’s
Easier weight gain Graying hair, thinning hair Wrinkling forehead & eyes Concern about biologic clock, financial security, family obligations Injuries "weekend warrior"
Signs of Aging in the 40s
Reflection on mortality, life’s limitations, unreached dreams & goals
Skin changes
Vision Changes
Osteoarthritis
Skin Changes in the 40’s
Sagging Wrinkling Thinning Benign & malignant issues Sweat glands
Vision Changes in the 40’s
Presbyopia
Require reading glasses
Signs of Aging in the 50’s & Early 60’s
Sense of aging Menopause Becoming a grandparent Death of parents, friends Oldest at work Physical limitations, medical problems Senior citizen discounts AARP membership
Signs of Aging in the 70’s & 80’s
1+ chronic disabling condition
Arthritis, HTN, hearing loss, heart conditions, visual problems, bone problems
Psychologic & social losses
Psychologic & Social Losses in the 70’s & 80’s
Retirement
Death of spouse or close family member
Children moving away
Friends dying or moving
Moving into apartment or retirement living
Inability to socialize from sensory or physical impairments
Aging & the Rule of Thirds
1/3 disease
1/3 inactivity
1/3 aging itself
Theories of Aging
Programmed phenomena Error theory Repair theory Redundancy failure Killer hormone theory
Describe the Programmed Phenomena
All cells bear specific “death” genes
Describe the Error Theory
Cellular DNA & RNA error
Accumulation of inappropriate proteins & enzymes
Unable to support cellular metabolism
Describe Repair Failure Theory
Failure of DNA repair
Describe Redundancy Failure
As cell ages, supply of redundant genes exhausted
Describe Killer Hormone Theory
Pituitary produces “killer” hormone destroying cell function
Advantages of Adaptation to Disability & to Role Losses
Greater independence
Fewer responsibilities
Reduces concern about day to day inconveniences
Financial security: SS, retirement programs
Hematologic Aging Changes
Slight decrease in RBC, Hgb, Hct WBCs increase in lobulation & decrease in granulation Changes in subsets of lymphocytes ESR increases slightly Physiologic anemia of aging Decreased reserve of RBCs
Musculoskeletal Changes in Aging
Height: lose 2-4”
Weight: men peaks in 50s & women in 60s
Increase in density, decrease in the water content of connective tissues
Calcification of connective tissue
Decreased bone mineral content
Decrease in muscle mass
Results of a Decrease in the Water Content of Connective Tissues
Loss of skin elasticity
Joint stiffness
Result of Calcification of Connective Tissue
Atherosclerotic changes
DJD
Bone Loss in Women Due to
Decreased estrogen production
Vitamin D absorption declines
Skin Changes with Aging
Decreased tone & elasticity Decline in subQ adipose tissue Yellowing of nails, rigid nails Hair loss after 30 in men Decrease in pigment
Respiratory Changes with Aging
Decrease in alveolar size
Vital capacity decreases progressively
Elastic recoil decreases due to changes in collagen
Forced residual capacity increases
Reduce expiratory flow velocities
All timed pulmonary functions decrease with age
CV Changes with Aging
Increased collagen in vascular smooth muscle Decreased elastic tissue Cardiac output decreases Slight reduction in resting heart rate Decreased organ perfusion Increased peripheral resistance Decreased vascular compliance Increased systolic BP
Renal Changes with Aging
Decrease in nephron units GFR & CrCl decline Peak bladder capacity reduced Residual urine increases Blood flow best at night Prostate gland doubles in size
Why the decrease in nephron units?
Kidney loses mass
Renal blood vessels thicken, lose elasticity
Medullary connective tissue increases, replaces interstitial cells
Loss of juxtamedullary glomeruli
Alimentary Canal Changes with Aging
Loss of teeth occurs secondary to bone & connective tissue changes
Periodontal disease
Poor nutritional status
Lack of dental care & poor hygiene contributes
LES fails to relax with peristaltic waves
Atrophic gastritis & pernicious anemia
Gastric secretions reduced (Achlorhydria)
Colon Changes with Aging
Decreased motor function
Depression of defecation reflex
Decreased colonic muscle tone
Decreased perfusion of GI tract secondary to vascular changes
Pancreatic Changes with Aging
Decrease in pancreatic lipase activity
Increased incidence of cholelithiasis
Aging Changes in Men
Increase fibrous tissue of interlobular spaces of testes
Thickening of the basement membrane around the seminiferous tubules
Sperm production decreases
Parathyroid Hormones & Changes in Aging
Levels decrease in women at 40 and men at 60
Changes in Miscellaneous Organ Systems with Aging
Decreased cerebral blood flow
Decreased vibratory sensation
Decreased hand grip, strength, coordination, writing
Changes within the Brain with Aging
Reduction in cerebral hemisphere mass
Decreased neurotransmitters
Delay in monosynaptic reflex arc
Motor time increases with aging
Sleep Complaints in the Elderly
Altered sleep patterns
More time in bed, less time sleeping
Frequent night time urination
Arthritic pain
Difference Between Memory Loss & Alzheimer’s Disease
Memory: worry about memory loss
Alzheimer’s: unaware of any mental impairment
Special Senses Changes with Aging
Cataracts
Macular degeneration
Decrease in visual receptors
Presbyopia
Decreased number of retinal rods, dark vision
Decreased hearing
Decreased vestibular function
Decreased number of tongue papillae & taste buds
Olfaction declines leading to poor nutrition
Weight loss
Psychological Aspects of Aging
Role changes: retirement Coping with medical illness Loss of spouse Friends dying Children are adults & far away or occupied with their own families
Laboratory Value Changes
ESR increases CrCl decreases Blood glucose rises Cholesterol risses Albumin falls T3 falls
Define Healthy Aging
Adaptation to the changes associated with the aging process that is acceptable to the individuals
3 Factors with Healthy Aging
Low probability of disease & disability
Higher cognitive & physical functioning
Active engagement in life
Define Disengagement Theory
Voluntary cutting back on work, social, & family ties
More satisfied with vicarious activities & reminiscing
Comes to terms with & accepts past failures
Describe the Prototypical Disengaged Person
Well known
Loved by neighbors
Happily spends all day rocking on the front porch
Define Activity Theory
Staying as active as possible
Continued professional or volunteer work
Social activities, family, hobbies
Define Continuity Theory
Allowing personal preferences from earlier years to manifest themselves as the individuals responds to the stress & challenges of older age
