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52 Cards in this Set
- Front
- Back
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Name the layers of epidermis from superficial to dermis
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stratum Corneum
stratum Granulosum stratum Spinosum stratum Basale |
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Which layer has Merkel cells & melanocytes
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stratum Basale
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how are cells attached to the basement membrane?
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Hemidesmosomes
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What cell layer do Langerhan cells live in?
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Stratum Spinosum
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In which epidermis layer does Vitamin D synthesis begin
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Stratum Spinosum
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What are Odland bodies and which epidermis layer are they found in?
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intracellular lipid membranes (eczema is result of abnormal odland bodies)
found in Stratum Granulosum |
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What is it called if there is a nucleus in the stratum Corneum?
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parakeratosis
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Which layer does Mitosis most frequently occur in?
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Stratum basale
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What binds cells in the stratum spinosum?
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Desmosomes
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What layer is Cytokeratin produced in?
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Cytokeratin: fibrillar protein, predominant protein made here
Made in stratum spinosum |
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What forms a heterodimer in the Stratum corneum?
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Acid & Base Keratin
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What ectopic layer does the dermis form from?
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mesoderm layer
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What is vernix caseosa?
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sebum plus periderm
Sloughed off exoderm greasy stuff that protects fetus from urine in amniotic fluid |
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What cells are found in the dermis layer?
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Fibroblasts (elastin, glycosaminoglycans, collagen), lymphocytes
mast cells macrophages |
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What is the collagen ratio (type I: III)
In a fetus? In an adult? |
Fetal 1:1
Adult: 4:1 |
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What % of dry weight of skin is collagen?
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70%
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Where does epidermis originate from?
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Ectoderm
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What is adnexae composed of and where does it originate from?
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hair, eccrine, apocrine, sebaceous glands
Ectoderm |
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What is Onycholysis? What two conditions do you see it
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separation of nail plate from nail bed, seen commonly w/ psoriasis and hyperthyroidism
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What is Papillary dermis?
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Superficial, thin layer just beneath epidermis, interlocks with rete ridge
Meissner's corpuscles present Small blood and lymphatic vessels arising from the vascular plexus Contains capillaries and unmyelinated nerves |
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What is Reticular dermis?
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Skin appendages: hair follicle with sebaceous, eccrine, apocrine glands Thicker, stronger, large compact collagen and elastic fibers Some arterioles, venules and nerves Elastin stains black against red staining collagen
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What is Hypodermis/Subcutis:
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Variable deep layer, mainly adipose tissue (fat lobules)
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What is Onychomycosis?
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Fungal infection of the nail
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What are the five concentric layers of epithelial cells in hair follicles?
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1) Medulla: Core of the hair shaft, moderate keratinization
2) Cortex: broad, highly keratinized layer, bulk of hair 3) Cuticle: hard, thin, keratinized surface, prevents matting of hair 4) Internal root sheath: lightly keratinized, leave space for sebum to enter 5) External root sheath: not part of hair formation, separated from follicle by glassy membrane (thick specialized basement membrane) |
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What causes goose bumps?
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Arrector pili muscle
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What are the three phases of hair Cycle?
How long is each stage and which determines hair length? |
anagen--> catagen-->telogen
anagen: longest cycle (3 years & 90% of hair), affected by chemotherapy, and its duration determines hair length; catagen: only 2 weeks long telogen: 3 months long |
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What are lanugo hairs?
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Baby hair
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What is the nutrient source for Propionibacterium acnes?
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Sebum from sebaceous glands
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What sort of secretion do sebacious glands do?
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Holocrine secretion
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Where do you not find Sebacious glands?
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Palms and soles!
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What is Miliaira?
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Clogged sweat glands
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Where doe you find apocrine secretion?
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Found in axilla, areola of nipples, genitals, perianal
region, external auditory canal |
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What is Hidradenitis Suppurativa?
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clogged, pus, sinus tracts +/- infected apocrine glands
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What is an Eccrine duct?
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hypotonic sweat relative to blood; merocrine secretion—no part of the
cell is secreted with sweat; cholinergic but sympathetic; not associated with hair |
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Why do ulcers leave scars?
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Because they involve the dermis and stimulate fibroblasts
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How does collagen progress in wound healing
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Collagen III first --> Collagen I
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How much strength can wounds gain?
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80% of unwounded skin
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What is the Koebner phenomenon?
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Disease occurring in areas of uninvolved skin after trauma (i.e. psoriasis and lichen planus)
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What are Rete ridges?
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junction between epidermis and dermis, downward folds of epidermis, offers resistance to
separation of epidermal surface due to shearing |
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What is a macule?
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flat, non-palpable circumscribed area of change in normal skin color, < 1cm
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What is a papule?
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superficially raised solid lesion, < 1cm, if shine light tangentially␣shadow
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Nodule?
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Rounded lesions, any size but usually < 1cm, regardless of depth but often said to be deeper than a papule (eg. a small inguinal LN)
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Pustule:
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small collection of pus in dermis/epidermis
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Petechiae
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pinpoint purpura (seen in thrombocytopenia)
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Purpura
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< 1 cm non-blanching red-purple macules—due to bleeding in skin (seen in leukocytoclastic vasculitis)
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Vesicles?
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Fluid-filled papule, superficial thin-walled: intraepidermal or subepidermal (but supradermal)
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Patch
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flat, non-palpable circumscribed area of change in normal skin color (macule but >1cm) (eg. depigmented patch of vitiligo)
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Plaque
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> 1cm elevation of the skin
Can be depressed or raised |
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Tumor
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"nodule" or "papule" > 1cm
Often a significant proportion of lesion is sub-epidermal ex Large and thick seborrheic keratosis, keloid, B-cell lymphoma |
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Ecchymosis:
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purpura >1cm (ex, DIC)
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Cyst:
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Closed cavity lined by epithelium
May contain fluid, water, pus, air, keratin, mucin, organisms etc. |
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Telangiectasis:
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Permanently ectatic (dilated) blood vessel in papillary dermis appearing as small, linear, red blanchable macules
dilation of the blood vessel ␣ not the skin lesion itself example spider spots in hepatic cirrhosis |
