Introduction to General Dermatology Flashcards
what is the largest organ in the body?
skin
the skin contains what adnexal structures?
(the parts adjoining an organ)
Hair, nails, glands, sensory structures
what are important roles that skin is involved in?
Important role in protection, homeostasis and transmission of sensations
what are the layers of the skin?
3 main layers
Epidermis is the outermost layer and made out of keratinocytes
Melanocytes are the cells that make pigment – everyone has same amount of melanocytes but different amount of melanosomes
Have acquired and innate immune system in the epidermis
Next you have junction attaching epidermis to the dermis
Collagen matrix
No blood vessels in the epidermis and all blood vessels in the dermis
Hair follicles
Erector papillae muscle aswell – Goosebumps for temperature control
Epidermis and dermis is different in different places in your body
It changes a you get older and don’t have same collagen and this is why you get pressure sores etc
Fat layer will be different in different places in the body
what are the layers of the epidermis?
study this picture showing the anatomy of the nail
what are the names of the different stages in the hair cycle?
Anagen
Catagen
Telogen
what happens in the anagen stage of the cell cycle?
active growing phase
80-90% of hair
what happens in the catagen stage of the cell cycle?
2–3 week phase growth stops/follicle shrinks
1–3% of hairs
what happens in the telogen stage of the cell cycle?
resting phase for 1–4 months
up to 10% of hairs in a normal scalp
what are the functions of skin?
Thermoregulation - Insulation, Heat transfer
Skin immune system - Innate and Adaptive functions
Barrier:
- Protects against Mechanical, Chemical, microorganisms, Ultraviolet light
- Keeps in water and Electrolytes, Macromolecules
Sensation - Temperature, touch and pain
Vitamin D synthesis - UV light converts 7-dehydrocholesterol to cholecalciferol
Interpersonal Communication - Physical appearance, smell, self-identity
what are the statistics relating to skin disease?
- 22-30% of Population affected
- 15% of consultations in general practice
- 6% of hospital referrals
- 50% skin cancer/lesions
- 25% require surgical procedure
- 10% require patch testing
what percentage of people with a skin problem seek care?
Why is skin disease important?
- Disfigurement
- Discomfort
- Disability
- Depression
- Death
what are the causes of skin disease?
- External - Temperature, UV, chemical (allergen or irritant), infection, trauma
- Internal - Systemic disease, genetics, drugs, infection