Physiological Changes of Ageing

Question 1

Why is it important to understand the physiological changes of ageing? (4))

Answer 1

Promote healthy ageing
Developing effective healthcare plan
Improvement of QoL
Reducing cost of healthcare

Question 2

Body Composition Changes per decade/year (2)

Answer 2

Loss of muscle mass after 30, 3-8% per decade, after 60 it’s 3% per year.
Muscle strength declines by 10-15% per decade.

Question 3

MSK Changes (4)

Answer 3

Atrophy:
↓ Type 2 (fast) fibers -> ↓ muscle mass -> ↓ strength and velocity of muscle contraction (↓ force generation) -> ↓ aerobic capacity.
↑ % of type 1 (slow) fibers.
↑ fat around muscle -> ↓ appearance of toned muscles.
↑ Non-contractile structures (fat + connective tissue) -> ↓ muscle cross sectional area -> ↓ potential muscle strength.

Question 4

Connective Tissue Changes (3)

Answer 4

Skin collagen and elastin synthesis declines
Fibers get thicker
Increased proteolysis of connective tissue

Question 5

Effect of Connective Tissue Changes (4)

Answer 5

Vessels and organs get rigid -> ↓ circulation -> longer recovery time / slower healing.
Contractile properties of tendons decrease.
Skin loses padding and elasticity due to ↓ thickness, ↓ elastin and ↑ collagen crosslinking.
↓ capillaries in skin -> Loss of blood supply -> sensitivity to touch, pain and temp.

Question 6

Skeletal System Changes - Articular Cartilage (2)

Answer 6

↓ nr of proteoglycans -> ↑ friction ↓ hydration.
Degeneration, thinning/damage and loss of water leads to OA.

Question 7

Skeletal System Changes - Bone (2)

Answer 7

↓ Bone density, ↑ crosslinking between collagen fibers - ↑ risk of fracture, stiffer joints.
Slow, limited movement with ↑ risk of fractures due to falls.

Question 8

Nervous System Changes - Key Changes (3)

Answer 8

↓ Nr of motor neurons -> ↓ strength and production of muscle force, ↓ muscle innervation -> ↓ strength and sensation.
↓ Action potential speed (info transport) -> ↓ fine motor control, slow reaction time (↑ risk of falls), slow initiation of movement.
↓ Axon/dendrite branches -> fine motor control.

Question 9

Peripheral Nervous System Changes

Answer 9

Motor and sensory autonomic fibers lost -> ↓ nr of innervated muscle cells -> muscle atrophy and denervation.

Question 10

Autonomic Nervous System Changes

Answer 10

↑ Sympathetic nervous system activity -> ↑ systemic vascular resistance, ↑ arterial BP.

Question 11

Endocrine System Changes (3)

Answer 11

↑ Body fat due to ↓ thyroid hormone -> ↓ metabolic rate & ↓ growth hormone -> ↓ muscle mass -> ↑ adipose tissue deposition.
↓ Bone density due to ↓ parathyroid hormone -> ↑ osteoclast activity.
Sleep disturbances due to ↓ melatonin.

Question 12

Endocrine System Changes - Risks (4)

Answer 12

Increased risk of insomnia, fractures, type 2 diabetes (↓ pancreatic activity -> insulin resistance -> ↑ glucose), Cognitive changes (sleep?)

Question 13

Temperature Control Changes (5)

Answer 13

Loss of thermoregulation:
↓ sweat glands, ↓ blood flow to skin surface -> overheating.
Thin skin -> loss of insulation, ↓ muscle mass, ↓ production of internal heat -> hypothermia

Question 14

Digestive System Changes (3)

Answer 14

Dysphagia (swallowing) -> malnutrition, aspiration pneumonia.
↓ hydrochloric acid -> ↓ absorption of nutrients + medication.
Slower peristalsis -> constipation.

Question 15

Urinary System Changes (3)

Answer 15

↓ Renal blood flow -> ↓ filtration rate.
↓ kidney size and nr of functional glomeruli -> ↓ filtration rate and and ability of excretion.
↓ elasticity and muscle strength of bladder and urethra -> ↑ frequency of urination, inability to fully empty bladder.

Question 16

Taste and Smell Changes

Answer 16

Eating becomes less interesting.
Affects QoL, malnutrition?

Question 17

Vision Changes (5) and Effect

Answer 17

Presbyopia (seeing up close)
↓ glare tolerance, color discrimination, attentional visual field -> affects driving, reading, balance, risk of fall, depression, social isolation, dependency.
↓ pupil diameter: needs more light -> increased risk of fall at night.

Question 18

Hearing Changes

Answer 18

↓ function and nr of neurons in semicircular canal -> vestibular system dysfunction -> balance impairment -> increased risk of falls.