Skin Flashcards
Skin functions
Sensation protection, thermoreguksgion, metabolic
What protects against UV light injury
Melanin
What part of the skin keeps water in and pathogens out
Epidermis
What is the dermis made of
CT
What type of cells is the epidermis made of
Stratified squamous
What are most of the cells in the epidermis?
Keratinocytes
Role of keratinocytes?
Form protective barrier
Where are basal keratinocytes found? What do they do?
In basal layer, give rise to new keratinocytes
Where are suprabasal keratinocytes found?
Anywhere above the basal layer, flattened, different differentiation markers
What are corneocytes?
Fully differentiated keratinocytes in cornified layer
As keratinocytes move up the skin, what do they accumulate?
Keratin
What are the key fibrous structural proteins in the epidermis
Keratin filaments
What part of the skin mitotically divides
Basil keratinocytes
What part of the skin moves up the strata
Suprabasal keratinocytes
Super Basil keratinocytes become highly organized and form what between each other
Desmosomes which are cellular junctions
What do desmosomal junctions appear as? What layer are the most easily seen in
Appear at spines and are seen in spinous layer
Corneocytes?
Fully differentiated keratinocytes that eventually shed from the surface
What is shedding from the surface of the skin called
Desquamation
Where are melanocytes found? What do the do
In the basal layer. Synthesize melanin granules
What do you Melanin granules do?
Provide pigment and photo protection (absorbs UV radiation)
What do dendritic projections do
Dispense melanin to keratinocytes
What are langerhans cells
A type of dendritic cell that is disbursed throughout the spinous layer
Where are Langerhans cells derived from? What do they do
Derived from bone marrow and they are antigen presenting cells. Because they are antigen presenting cells, they activate naïve T cells in the immune system
What does the basement membrane do?
Controls the traffic of cells and molecules between layers and structurally tethers the dermis and epidermis together
What is the dermis composed of and what does it support
Composed of matrix proteins and mucopolysaccharides. Supports the glands and follicles
What type of tissue is the dermis made of
Connective
What layer of the skin provide structural integrity and elasticity?
The dermis
How does the dermis provide structural integrity and elasticity?
Collagen, microfibrils, elastic fibrils
What are the five dermal appendages
Nails, hair, sebaceous glands, eccrine sweat glands,apocrine sweat glands
What are the two major categories of skin diseases
Growths and rashes
Name the four types of growths
Cyst, malformation, neoplasm, bumpy skin
What are the two types of rashes
Danielle plastic, inflammatory skin conditions
What is a patch or macule
Areas of discoloration without noticeable change in texture. Patches are over 1 cm and macules are less than 1 cm
What are plaques in papules
Elevated palpable skin lesions where the width exceeds the thickness. Plaques are over 1 cm and papules are less than 1 cm
What are bullae and vesicles
Fluid filled spaces in the skin. Bullae are over 1 cm and vesicles are less than 1 cm
What is perivascular dermatitis without epidermal change
Perivascular inflammation infiltrate without significant involvement of the epidermis
What is spongiotic dermatitis
Inflammatory infiltrate associated with intercellular epidermal Edema
what is psoriasiform dermatitis
Inflammatory infiltrate associated with epidermal thickening as a result of elongation of rete ridges
What is interface dermatitis
Set a toxic inflammatory reaction with prominent changes in lower epidermis, characterized by vacuolization of keratinocytes
What is vesiculobullous dermatitis
Inflammatory reaction associated with intra-epidural or sub epidural cleavage
What is small vessel vasculitis
Inflammatory reaction focused on the walls of cutaneous vessels
Folliculitis
Inflammatory reaction directed against folliculosebaceous units
What is nodular dermatitis
Inflammatory reaction with a nodular or diffuse dermal infiltrate in the absence of significant epidermal changes
What is panniculitis
Inflammatory reaction involving the subcutaneous fat
What happens to skin as it ages
Becomes thinner, dryer, wrinkled, changes in pigmentation, capillary loops shorten and decrease, fewer melanocytes and Langerhans cells, gland atrophy
