Intro to Dermatology and Epidermis Flashcards
What is the most prevalent condition for people seeing their doctor?
skin disorders
What is the most common global skin disease?
Dermatitis (by a lot). Then Acne
What type of epithelium is the most superficial epidermis?
stratified squamous
What are all the components of skin? (layers, etc.)
Epidermis Dermis Adnexal structures subcutaneous fat Regional thick skin layer (on palms, feet)
What are the different adnexal structures?
- Apocrine glands
- Eccrine glands
- Hair
- Nails
- Sebaceous glands
Name the two layers of the dermis
- the papillary layer (loose connective tissue) lies immediately under the epidermis
- a deeper reticular layer (dense connective tissue)
Where do you find keratinocytes?
Epidermis (stratum basale)
They are the stem cells
List the five layers of epidermis from superficial to deep
- stratum corneum
- stratum lucidum (only present in thick skin)
- stratum granulosum
- stratum spinosum
- stratum basale
“california loves girls- stupid and blonde”
“can lovers go (to) second base?”
What do you find in the granules of stratum granulosum
Inside Keratohyalin granules, you find profilaggrin = precursor to filaggrin
What does filaggrin do?
Filaggrin cross-links keratin tonofilaments and is important in the barrier function of the skin
Becomes NMF to moisturize skin
Which layers lost their nuclei and organelles?
corneum and lucidum
What is the important structural characteristic of the stratum spinosum?
Desmosones attach cells together!
Has a “prickly” or spiny appearance due to desmosome attachments between cells
• intercellular adhesion depends upon the tonofilament desmosome interaction in the distribution of stress
What type of epithelial layer is the stratum basale?
Single layer of cuboidal or columnar
How is the stratum basale attached to the dermis?
Hemidesmosomes: attach basal cells are firmly to the basal lamina of the dermal epidermal junction
Where do you find the stem cells of the epidermis?
Stratum basale
Basal keratinocytes are the stem cells of the epidermis (the source of new keratinocytes and thus a site of intense proliferation)
What are tonofilaments?
protein structures (keratin filaments) that insert into the dense plaques of desmosomes on the cytoplasmic side of the plasma membrane
What are the functions of the skin?
- Decoration/Beauty
- Barrier
• Physical
• Light
• Immunologic - Vitamin D synthesis
- Water Homeostasis
- Thermoregulation
- Insulation/Calorie Reservoir
- Touch/Sensation
What cell acts as a light barrier? Where is it found?
melanocyte > epidermis
What cell acts as a physical barrier?
keratinocyte
What cell does vitamin D synthesis
keratinocyte
What cell acts a immunological barrier and where is it found?
Langerhans cells > epidermis
These are the antigen presenting cells (dendrites) of the skin
What cell gives your skin strength and elasticity? Where is it found?
Fibroblast in the dermis (Produces collagen and elastin)
How are the Fitzpatrick skin types classified?
Type I: Never tans, always burns- white
Type II: Tans with difficulty, usually burns- fair
Type III: Average tanning, sometimes burns- light brown
Type IV: Easily tans, rarely burns- moderate brown
Type V: Very easy to tan, very rarely burns- dark brown
Type VI: Never burns- black
T/F: skin color variation is due to number of melanocytes?
False
Due to the type of melanin produced
– Eumelanin: black to brown pigment
– Pheomelanin: yellow to red-brown pigment
Due to the distribution melanosomes
– Light Skin: melanosomes distributed in clusters above the nucleus
– Dark Skin: melanosomes distributed individually throughout the cytoplasm
