Basic skin terminology Flashcards
What are the layers of the skin
Skin has 3 layers: epidermis, dermis, subcutaneous fat (hypodermis, subcutis)
What are the layers of the epidermis from superficial to deep
“Come, Lets, Get, SunBurned”
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosim
Stratim basale
Dermis
What are the epithelial cell junctions
Tight, adherens, desmosome, hemidesmosome, gap, and integrins
Function and composition of tight junctions
Also called zonula occludens, prevents paracellular movement of solutes
Composed of claudins & occludins
Function of adherens junction + loss
Aka belt desmosome/zonula adherens, forms “belt” connecting actin cytoskeletons of adjacent cells with cadherins (Ca2+ dependent adhesion proteins)
Loss of E-cadherin promotes metastasis
Function and disease in loss of desmosomes
Aka spot desmosome/macula adherens, structural support via intermediate filament interactions
Autoantibodies to desmoglein 1 and/or 3 = pemphigus vulgaris
Function of gap junctions
Channel proteins called connexons permit electrical and chemical communication between cells
Function & disease hemidesmosome
Connects keratin in basal cells to underlying basement membrane
Autoantibodies = bullous pemphigoid
Function of integrins
Membrane proteins that maintain integrity of basolateral membrane by binding to collagen, laminin, and fibronectin in basement membrane
What are exocrine glands and types
Glands produce substances other than hormones (vs endocrine glands, which secrete hormones) that are released through ducts to the exterior of the body
Can be merocrine (eg, salivary and sweat glands), apocrine (eg, mammary glands), or holocrine (eg, sebaceous glands)
Characteristics and examples of a macule
Macroscopic, flat lesion with well-circumscribed change in skin colour < 1 cm
Ex. freckle (ephelis), labial macule
Characteristics and examples of a patch
Macule > 1 cm
Ex. large birthmark (congenital nevus)
Characteristics and examples a papule
Elevated solid skin lesion < 1 cm
Ex. Mole (nevus), acne
Characteristics and examples of plaques
Papule > 1 cm
Ex. Psoriasis
Characteristics and examples of vesicles
Small fluid-containing blister < 1 cm
Ex. Chickenpox (varicella), shingles (zoster)
Characteristics and examples of bullas
Large fluid containing blister > 1 cm
Ex. Bullous pemphigoid
Characteristics and examples of pustules
Vesicle containing pus
Ex. Pustular psoriasis
Characteristics and examples of wheal
Transient smooth papule/plaque
Ex. Hives (uriticaria)
Characteristics and examples of scale
Flaking off of stratum corneum
Ex. Eczema, psorasis, SCC
Characteristics and examples of crusts
Dry exudate
Ex. Impetigo
Characteristics and examples of dyskeratosis
Microscopic, abnormal premature keratinization
Ex. squamous cell carcinoma
Characteristics and examples of hyperkeratosis
Increased thickness of stratum corneum
Ex. psoriasis, calluses
Characteristics and examples of parakeratosis
Retention of nuclei in stratum corneum
Ex. psoriasis, actinic keratosis
Characteristics and examples of hypergranulosis
Increased thickness of stratum granulosum
Ex. Lichen planus
Characteristics and examples of spongiosis
Epidermal accumulation of edematous fluid in intercellular spaces
Ex. Eczematous dermatitis
Characteristics and examples of acanthylosis
Separation of epidermal cells
Ex. Pemphigus vulgaris
Characteristics and examples of acanthosis
Epidermal hyperplasia (increased spinosum)
Ex. acanthosis nigricans, psoriasis
