The ageing skin and GI tract Flashcards
What are the functions of the skin?
Protect Barrier Thermoregulation Perception (touch, vibration, temperature, pain) Vitamin D production
What happens to old age skin?
epidermal and dermal layer atrophy
less blood vessels in dermis
loss of collagen fibres
How does the old age skin affect the function of the skin acting as a barrier?
decreased sebum production
epidermal thinning
How does the old age skin affect the function of the skin acting as a thermoregulator?
dermal thinning
less moisture retention
less ability to vasodilate= so heat retention
How does the old age skin affect the function of the skin acting as a protector?
UV damages skin
loss of telomere ends (which removes damaged DNA)
reduce nail growth by 50%
How does the old age skin affect the function of the skin acting as a pain receptor?
dermal thinning- less nerve endings
How does the old age skin affect the function of the skin acting as an endocrine?
less ability to synthesise vit D
less ability to synthesise melanin ➔ prone to skin cancers (in addition to photodamage done in previous years)
What is xerosis/xerdoderma?
dryness of the skin or cracking
What does dry skin affect?
the barrier of the skin
In old age, there is flattening of the junction between what and what does this cause?
between dermis and epidermis (no rete ridges and dermal papillae)
causes
1. less nutrient transfer to epidermis bc smaller surface area
2. protective lipids not transferred into stratum corneum of epidermis
What happens to the number of sweat glands in the ageing skin?
reduces
causes dry skin
What related to immunity is reduced in the epidermis of the ageing skin?
langerhan cells so there is less protction
What is pruritis?
chronic itching of the skin- can be caused by dry skin
What causes wrinkling of the skin?
epidermis thins
decline in elastin synthesis (after 40 years)
decrease in subdermal fat skin
What factors lead to increased susceptibility to trauma?
dermis and epidermis junction is weaker
so more likely to get tears here
and more bleeding comes into this gap
What leads to delayed wound healing?
dermis thins because of less vascularity and less collagen and elastin synthesis
longer transit time for keratinocytes to reach upper stratum corneum
What are external factors that lead to pressure ulcers?
- excessive pressure on a part of the skin
- friction and shear forces
- impact injury
- heat
- moisture
- posture
What are the internal factors that lead to pressure ulcers?
- immobility (lack of movement)
- sensory loss (so the patient will not be able to sense pain)
- age
- diseases such as diabetes
- body type
- poor nutrition
- infection
- incontinence
How many grades are pressure ulcers classified into?
4
1= calm
4= worst
Why is thermal regulation impaired in ageing skin?
loss of dermal capillaries
less subdermal fat (less insulation)
less sweat glands produced
Why is there impaired sensory perception in ageing skin?
Less meissner’s corpuscles= LIGHT TOUCH
Less pacinian corpuscles= LOW FREQUECY VIBRATION
Why can’t ageing skin produce Vitamin D as effectively?
UV converts 7 dehydrocholestrol to pre vitamin D3 in the epidermis
in older skin, 7 dehydrocholestrol levels are less= so less vitamin D production
What can prolonged vitamin D deficiency lead to?
- less Ca and phorphorus absorption in intestines
- hypocalcaemia= can lead to secondary hyperparathyroidism
= that leads to phosphate secretion in urine, demineralization of bones etc
= leads to osteopenia (less mineral in bones) and osteomalacia (softening of the bones)
= can lead to fractures, muscle weakness, and bone pain
What is photoageing?
sun exposure affects the skin
What does photoageing lead to?
cellular dysplasia (wrong cells in wrong place)
atypical (abnormal) cells
epidermis disorganized
less collagen content
What is achromotrichia?
greying of hair in the elderly
Why does achromotrichia take place?
less melanocytes in epidermis and hair