Introduction to Dermatology Flashcards
What is the largest organ in the body?
Skin
What are some skin adnexal structures?
Hair
Nails
Glands
Sensory structures
What are important functions of the skin?
- Protection
- Homeostasis
- Transmission of sensation
What are the layers of the skin from superficial to deep?
Epidermis
Dermis
(then below but not part of the skin is the hypodermis)
What are the layers of the skin from superficial to deep (invidividual layers)?
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
What forms the stratum corneum?
Dead cells with a hard protein envelope
Cells contain keratin and are surrounded by lipids
What forms the stratum lucidum?
Dead cells lie within despersed keratohyalin
What forms the stratum granulosum?
Keratohyalin and a hard protein envolope
Lamellar bodies release lipids
Cells die
What forms the stratum spinosum?
Keratin fibres and lamellar bodies accumulate
What forms the stratum basale?
Cells divide by mitosis and some of the newly formed cells become the cells of the more superficial streta
What within the skin releases lipids?
Lamellar bodies
What is A?
What are the 3 different stages of the hair cycle?
Anagen
Catagen
Telogen
What is the anagen phase of hair cycle?
Active growing phase
What is the catagen phase of hair cycle?
2-3 week phase growth stops/follicles shrink
What is the telogen phase of hair cycle?
Resting phase for 1-4 months
How long does the telogen phase of hair cycle last?
1-4 months
How long does the catagen phase of hair growth last?
2-3 weeks
During what phase of the hair cycle is most hair in?
Anagen (80-90% hair)
Telogen (up to 10% of hair)
Categen (1-3% of hair)
What are some functions of the skin?
- Thermoregulation
- Insulation, heat transfer
- Skin immune system
- Innate and adaptive functions
- Barrier
- Protects against mechanical, chemical, microorganisms, UV light
- Keep 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
The skin acts as a barrier to protect against what?
Mechanical, chemical, microorgasms and UV light
What kinds of sensations does the skin transmit?
Temperature
Touch
Pain
How does the skin perform vitamin D synthesis?
UV light converts 7-dehydrocholesterol to cholecalciferol
How much of skin disease is skin cancer/lesions?
50%
Why is skin disease important?
- Disfigurement
- Discomfort
- Disability
- Depression
- Death
What are some causes of skin disease?
- External
- Temperature
- Cold injury
- Frostbite, chilblains
- Skin necrosis
- Cold urticaria
- Cold injury
- UV
- Called photosensitivity
- Commonly caused by medications
- Exposed sites affected
- Can be sensitive to UVA, UVB, visible light or a combination
- Chemical
- Infection (allergen or irritant)
- Trauma
- Dermatitis artefacta (skin lesions solely produced by patients own actions)
- Temperature
- Internal
- Systemic disease
- Genetics
- Drugs
- Think of OTC drugs
- Infection
- Autoimmune
- Bullous pemphigoid