Basic Skin Biology Flashcards
(33 cards)
What are the functions of the skin?
- Protective barrio against environmental insults
- Temperature regulation (thermoregulates)
- Sensation
- Vit D synthesis
- Immunosurveillance
- Cosmesis
What is the most severe emergency presentation?
- Erythematous (Redness)
- Extensive (covering majority of skin)
- Exfoliative: Upper layer of skin is sliding of
Erythematous extensive exfoliative rash
What is erythroderma?
A presentation which results from several skin conditions as a complication
- Total skin failure
What are the complications of erythroderma?
- Hypothermia (loss of thermoregulation)
- Infection (loss of protective barrier) -> sepsis
- Renal failure (insensible losses)
- High output cardiac failure (dilated skin vessels)
- Protein malnutrition (high turnover of skin as loss of top layer of skin)
How much of the body can be affected by erythroderma?
> 90% of body surface area
erythematous and exfoliative
What are causes of erythroderma?
- Psoriasis
- Eczema
- Secondary complication of drugs
- Cutaneous T cell lymphoma (cancer)
What are some symptoms of erythroderma?
- Pruritus
- Fatigue
- Anorexia
- Feeling cold
What some signs of erythroderma?
- Erythematous
- Thickened
- Inflamed
- Scaly
- No sparing (superficial and deep affected)
What are the layers of skin?
Epidermis
Dermis
What are the 4 types of cells in epidermis?
- Keratinocytes - protective barrier
- Langerhan cells- antigen presenting cells
- Melanocytes- produce melanin which provides pigment to the skin and protects cell nuclei from UV DNA damage
- Merkel Cells - contain specialised nerve endings for sensation
What are the 4 layers of the epidermis?
- stratum corneum
- stratum lucidum (in areas of thick skin like palms)
- stratum granulosum
- stratum basale
What stages of maturation do the-epidermal layers represent and what is cell turnover time?
Each layer represent different stage of maturation of keratinocyte
Average epidermal turnover time is 30 days
What can pathology in epidermis cause?
- a) Change in epidermal turnover
- b) Change in surface of the skin
- c) Changes in pigmentation of the skin
Give 2 examples of pathology of the epidermis
- Psoriasis
- Vitiligo
What are common presentation of psoriasis?
- Erythematous
- Scaly
- Plaques
What are common presentation of psoriasis?
- Erythematous
- Scaly
- Plaque
What causes the appearance of psoriasis?
Increased cell turnover
What is vitiligo?
Patches of make skin
Autoimmune disorder
Hypopigmentation in certain parts of the body
Give 2 examples of pathology of the epidermis
- Psoriasis
- Vitiligo
What is the dermis?
Made of collagen, elastin and glycosaminoglycans
Provides strength and elasticity
What is contained in the Dermis?
immune cell
nerve cells
skin appendages
lymphatics
blood vessels
hair bulbs
sweat glands
Give some examples of pathology of the dermis
- Dermatographia
- Acne vulgaris
What is dermatographia?
- raised bumps when touched - wheel
- Oedema in dermal layer causing the bump
What is the role of sebaceous glands?
- Produce sebum through hair follicles (pilosebaceous unit)
- Secretes sebum to skin for lubrication
- Active post puberty
- Stimulated by conversion of androgen to dihydrotestosterone
