Skin Flashcards
Layers of epidermis (deep to superficial)
Stratum Basale
Stratum Spinulosum
Stratum Granulosum
Stratum Corneum
Melanocytes and langerhans cells are found in ____
epidermis
____ make up of 90% of cells in epidermis.
Keratinocytes
Cells of the stratum basale are attached to the basement membrane by ____
hemidesmosomes
Keratinocytes of the stratum spinulosum and basale are attached to each other by ____
desmosomes
Cytoplasmic plaques of desmosomes composed of (2)
Plakoglobin
Desmoplakin
4 layers of basement membrane zone (superficial to deep)
Plasma membrane of basal keratinocytes
Lamina lucida
Lamina densa: type 4 collagen
Sub basal lamina
2 layers of dermis
Papillary dermis
Reticular dermis
Papillary dermis:
Made of ___
Contains (2)
Controlled by:
Loose connective tissue, mainly type 3 collagen
Meissner’s corpuscles, vascular networks
Sympathetic nervous system
Reticular dermis:
Made of ___
Function:
Contains:
Dense irregular connective tissue, mainly Type I collagen
Strength and elasticity
Glands and hair follicles
Vater-Pacini corpuscles
Mediate sense of pressure
Not affected by anesthesia
Tyrosinase
converts tyrosine to melanin within melanosomes in melanocytes
Found everywhere on skin except palms and soles
Sebaceous glands
Found mainly in axillae and genital regions
Apocrine glands
Sebaceous glands are under __ control
endocrine
Apocrine glands are under __ control
adrenergic sympathetic innervation
Eccrine glands
sweat glands
Pilosebaceous unit
Hair + sebaceous gland
3 cycles of hair growth
Anagen: active growth phase
Catagen: growth arresting phase
Telogen: resting phase/shedding phase
Hyponychium
skin underlying free end of nail
3 major protein components of cornified envelope
Enzyme that catalyzes the crosslinks
Loricrin Involucrin Keratolinin "LIK the envelope" Transglutaminase 1
Major membraine lipids of stratum corneum
Ceramides
Tightly packed and highly impermeable to water
Lamellar granule or keratohyalin granule?
Membrane bound
Lamellar granule
Lamellar granule or keratohyalin granule?
Not membrane bound
Keratohyaline granule
Lamellar granule or keratohyalin granule?
Location: upper spinous layers
Both
Lamellar granule or keratohyalin granule?
Primary site of activity: Granular-cornified layer interface
Lamellar granule
Metabolically inert, enucleated cells formed from keratinocytes in the viable lower layers of the epidermis
Corneocytes
Lamellar granule or keratohyalin granule?
Primary site of activity: granular layer & cornified layer
Keratohyaline granule
Lamellar granule or keratohyalin granule?
Deliver precursors of stratum corneum lipids into intercellular space
Lamellar granule
Lamellar granule or keratohyalin granule?
Deliver free amino acids to outer layers of stratum corneum (filaggrin monomers)
Keratohyaline granule
Lipid content of lamellar granule function:
Maintain vapor barrier and signaling cell turnover
Filaggrin in cornified cells function:
Matrix protein that promotes aggregation of keratin filaments
Sweat secretion controlled by ____
hypothalamus
UVC =
200-290 ozone layer
UVB =
290-320 Burning ray
UVA =
320 - 400 Tanning ray
Present in dermis and induce immediate hypersensitivity response
Mast cell
Produce pro-inflammatory cytokines (IL-1) and express MHC class II antigens and intracellular adhesion molecules
Keratinocyte
