Physiology of Ageing Flashcards
Life span
The potential maximum to which a species can live from a given age
Life expectancy
The average number of years a person may live from a given age
Healthy life expectancy
The average no. of years a person may live in good health from a given age
Age related change must
- Be deleterious
- Be progressive
- Be intrinsic
- Be universal
General changes of ageing
- Loss of height
- Loss of fat free and lean body mass
- Gain and redistribution of adipose tissue
Skin Aging involves:
- Slowing of keratinocyte generation
- Loss of elasticity in dermis
- Thinning epidermis
- Lumps and bumps
- Pathology: ulcers, skin cancer (BCC, SCC)
- Blotchiness
- Wrinkles
Sun damage/photoaging leads to
- Solar elastosis - ultraviolet radiation breaks down elastic tissue in skin
- Solar lentigines - dark brown spots that appear with age
- Melama - dark patches of skin usually on the face and related to female hormones
- Actinic keratoses - rough, scaly areas of skin
Solar aging process
- UVB can cause DNA mytation directly by creating compounds that affect pyrimidine bases
- UVA penetrate into dermis and damage leads to smaller dermis and damage to blood vessels. Damages DNA directly through production of Reactive Oxygen Species
- UV, inflammation and production of cytokines that attract neutrophils and can lead to free radical generation
- UV can lead to vitamin A deficiency in the skin
What are Langerhans?
Dendritic cells which, on infection of an area of skin, take up and process microbial antigens to become fully-functional APCs - these reduce as we age
Repairing damaged skin with retanoids
These are related to Vitamin A and can alter the structure of skin, partly reversing or slowing the process of photoaging
Effects of Aging on Musculoskeletal system
- Sarcopenia
- inactivity
- loss of motor neuron innervation
- Bone resorption begins to exceed bone formation, can –> osteoporosis
- Change in physical properties of cartilage
- Loss of muscle mass and strength
- reduction in baseline protein production rate
- activity related
- fat infiltrating muscle plays a role
- reduction in baseline protein production rate
Ageing on the CV system
- Stiffening, widening of large arteries
- Reduced ability to contract and dilate smaller arteries
- Cardiomegaly
- Reduced responsiveness to exercise
- Postural hypertenstion
Pathology:
- Arteriosclerosis
- Atherosclerosis
- Coronary Heart Disease
- Ability of aorta to expand under pressure decreases with age –> increased blood pressure
Systolic pressure increase
>75yo reduced baroreceptor sensitivity
Ageing on the respiratory system
- Intercostal and diaphragm muscles weaken
- Lung tissue becomes less elastic
- Reduced cilliary function
- Impaired ventilation
Pathology
- lung cancer
- bronchitis
Ageing on GI system
- Reduced absorption
- Reduced mucus secretion –> increased risk of trauma and infection
- Reduced motility
- Reduced hepatocytes
Pathology
- Diverticulosis
- Gallstones
- Cancer
Ageing on GU system
- GFR decreases with age
- Adaptability to change slows
- Reduced ability to postpone bladder voiding
- Cannot completely void bladder contents
- Prostatic hypertrophy
Pathology
- Urinary incontinence
- Prostate hyperplasia
- Prostatic cancer
