system Test Questions and Solutions
Skin ✅Largest body organ, variable thickness (1.5-4mm) 7% body weight (9-11
pounds)
Epidermis ✅Superficial layer, stratified squamous epitheilium - 30-50 layers thick,
superficial cells are dead, contains keratin.
Dermis ✅Inner layer of the skin, thicker than epidermis, increased collagen and elastic
fibers, increased vascularity, contains nerves, glands, hair follicles.
Papillary layer ✅Dermal layer. Connects to epidermis - has dermal papillae, capillary
loops, Meissner corpuscles. Fingerprints formed from here.
Reticular layer ✅Deeper, thicker, flexible - extensible
Tension lines:***
Flexure lines: ***
Linea albicans: Stretch marks
Tearing of the dermis due to overstretching - mark is increased collagen repaired
dermis
Hypodermis ✅Subcutaneous tissue, binds dermis to underlying tissue, primarily
connective tissue, adipose, vasculature, varies with body region, sex, age, nutritional
state
Stratum corneum ✅Epidermal layer, flat, keratinized, cornified.
Stratum lucidum ✅Epidermal layer. Extra layer found in palms, soles of feet only
Stratum granulosum ✅Epidermal layer. Granular cells, produces keratin. Contains
keratinocytes which produce keratin
Stratum spinosum ✅Epidermal layer. Limited mitosis. Contains Langerhans cells -
activate immune response.
Stratum basale ✅Deepest epidermal layer. Highly mitotic. Contains
Melanocytes - produces melanin
Merkel cells - sensory nerve ending
Cornification ✅The flattening and drying of cells at the corneum. Friction stimulates an
increase in stratum basale mitosis and keratin production causing callus formation