Skin and Wound Healing Flashcards
Functions of the skin
Mechanical barrier/protection Immune system component Thermoregulation Fluid regulation Vit D production Sensory organ Appearance Storage
Epidermis layers
Stratum corneum Stratum lucidum (only in palms and soles) Stratum granulosum Stratum spinosum Stratum basale
Cell types in epidermis
Keratinocytes
Melanocytes
Langerhans cells
Merkel cells
Basement membrane
anchors the epidermis to the dermis
Primarily collagen fibers but also has some antigens
Genetic skin disorders sometimes occur in this layer
Loose CT (areolar)
Widely throughout body
Very haphazard arrangement with large amount of space
Fiber type dependent on location
Dense CT
Irregular - dermis, capsule, surrounding mm - collagen fibers with somewhat irregular arrangment
Regular - ligaments, tendons - collagen fibers packed and arranged in parallel fashion
Dermis - layers
Papillary dermis
Reticular dermis
Dermis -
primarily collagen with hyaluronic acid matrix
Interspersed with vessels (blood) and myelinated nerve endings
Also contains lymph vessels
Cells within dermis
Fibroblasts - major
Macrophages, other WBCs
Mast cells
Appendages with deneration from epidermal cells
Nails
Sebaceous glands
Hair follicles
Sweat glands
Subcutaneous tissue
mostly loose CT
Fat cells - cushion storage, insulation
Collagen - fascia
Blood vessels incluing lymph vessels
Blood and lymph - located in
the dermis and subcutaneous tissue
Epidermis has no blood vessels
Lymph vessels parallel blood vessels
Innervation of skin
Merkel cells Meissner corpuscles Pacini corpuscles Raffini corpuscles Free nerve endings
Appocrine glands (skin color)
increased number in dark skinned
Eccrine glands (skin color)
About the same across races
diet influences secretions
Macule
Flat lesion
Different color from surrounding tissue
Less than 1cm in diam
Patch
large macule - so also flat
larger than 1cm diam
Papule
Elevated lesion
firm, circumscribed (you can feel edges)
less than 1 cm
Nodule
elevated, firm lesion
deeper into dermis than papules (also in subQ tissue)
learger than 1 cm
plaque
elevated, firm
rough surface (maybe shedding)
greater than 1 cm
seen with psoriasis
Vesicle
elevated, serous, fluid filled
circumscribed
superficial (no deeper than upper layer, maybe to BM)
less than 1 cm
if cause is viral infection - the fluid inside has the active pathogen
Bulla
fluid filled vesicle
larger than 1 cm
blister
Wheal
Elevated, usually firm
may be irregular shaped but well demarcated
(insect bite)
Epidermal
Pustule
Pus filled vesicle
most often infected but not always
Cyst
Elevated
encapsulated
circumscribed
liquid or semisolid
Keloid
Irregular shaped
Elevated
Enlargement beyond the borders of the scar
Excessive collagen formation
Documenting lesions
characteristics
patttern
location and distribution
drainage/exudates
Striae
Areas that undergo progressive stretching
Dermal layer damage with thinning of the epidermis
Excessive mast cell degranulation
Collagen and elastin fiber damage
Spider veins (Telangiectasis)
Superficial venous system in that area is becoming insufficient
Intradermal nevi (mole)
Classic from epidermis
not always elevated - can be flat
Color is important - check consistency
Hyperkeratosis
verrucous cobblestone plaques
Inc proliferation of fibroblasts and keratinocytes due to tissue lymph stasis
very firm
non pitting
Warning signs
A - Asymmetry B - Border C - Color D - Diameter E - Evolving
