Structure and Function of the Skin Flashcards
What are the 5 layers of the skin from basement mambrane to surface?
- Stratum Basale
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum
- Stratum corneum
What is the function of the stratum basale?
Cells divide by mitosis and some of the newly formed cells become the cells of the more superficial strata
What is the function of the stratum spinosum?
Keratin fibers and lamellar bodies accumulate
What is the function of the stratum granulosum?
Keratohyalin and a hard protein envelope form; lamellar bodies release lipids; cells die
What is the function of the stratum lucidum?
Dead cells lie within dispersed keratohyalin
What is the function of the stratum corneum?
Dead cells with a hard protein envelope; the cells contain keratin and are surrounded by lipids
What are the functions of the skin?
Thermoregulation
Skin immune system
Barrier
Sensation
Vitamin D synthesis
Interpersonal Communication
How does the skin provide thermoregulation?
Insulation through fat layer below dermis and hair follicles on surface
Heat transfer through sweating
How does the skin act as a barrier?
Protects against: Mechanical, Chemical, Microorganisms, Ultraviolet light
Keeps in water and Electrolytes, Macromolecules
How is the skin involved in Vitamin D synthesis?
UV light converts 7-dehydrocholesterol to cholecalciferol
How is the skin ivolved in interpersonal communication?
Physical appearance
Smell
Self-identity
How common is skin diseas?
22-30% of Population affected
15% of GP consultations
6% of hospital referrals
What is the majority of dermatology work made up of?
50% skin cancer/ lesions
25% require surgical procedure
10% require patch testing
What percentage of dermatology patients dont see a doctor about their problem?
80%
No need and can usually be dealt with at home.
What factors make skin disease important?
Disfigurement Discomfort Disability Depression Death
What are the external causes of skin disease?
- Temperature
- UV
- Chemical (allergen or irritant)
- Infection
- Trauma
What are the internal causes of skin disease?
- Systemic disease
- Genetics
- Drugs
- Infection
What is photosensitivity?
Abnormal reaction of the skin to sunlight
Burn when they have had an abnormally low level of UV exposure
What sites are effected in Photosensitivity?
Exposed sites around neckline and arms
Under chin usually spared
What causes photosensitivity?
Commoly caused by medications
What should you test in photosensitivity?
Patient can be sensitive to UVA, UVB, visible light or a combination of these.
Need to test different wavelengths of light
What are chilblains?
A painful, itching swelling on a hand or foot, caused by poor circulation in the skin when exposed to cold.