Chapter 1 Skin Flashcards
From where does apocrine sweat units and sebaceous gland originate?
Apocrine frim upper follicular epithelium
Sebaceous from midregion of follicle
What is the pattern of merkel cell when with poly and monoclonal keratin 20 staining?
Paranuclear dot
Mutation in keratin 5,14 and 1,10 result to?
Epidermolysis bullosa simplex
Epidermolysis keratosis
Respectively
What regulates epidermal differentiation?
Histones
3 manifestations of abnormal keratinization?
Parakeratosis (retained nuclei) Corps ronds (rounds, clear to pink abN keratinized cells) Grains (elongated, basophilic, abN keratinized)
What are the phases of keratinization?
Synthetic
Degradative
What are responsible for desmosomal adhesion?
Cadherins
Desmogleins and desmocollins (Calcium dep)
Responsible for keratin filament aggregation
Filaggrin
Melanocyte:keratinocyte ratio?
1:10
Appearance of melanocyte in H&E stain?
Cell with ample amphophilic cytoplasm or as a clear cell in the basal layer of epidermis
Where are melanosomes produced?
Golgi bodies
Reason for red head?
LOF mutation in melanocortin 1 receptor (MC1R) –> eumelanin to pheomelanin
Reason for vitiligo and albinism?
Vitiligo - destruction of melanocyte
Albinism - N # of melanocyte, unable to fully pigmented melanosomes
Layer of epidermis where langerhan cells are found?
Spinosum
Stain for langerhans? How do they appear?
Gold chloride, CD1 alpha, S-100
Dendritic cells in sections, with folded nucleus and distinct intracytomplasmic organelles and birbeck granules
Where does langerhans originate
Bone marrow
Monocyte-macrophage lineage
Function of langerhans
In the afferent limb of immune response by providing for recog, uptake,processing and presentation of antigens to sensitized T lympho; impt in induction of delayed type hypersensitivity
Components of dermoepidermal junction
Plasma membranes of basal cells with hemidesmosomes; lamina lucida; lamina densa (basal lamina); fibrous comp (anchoring fibrils, dermal microfibrils, collagen)
2 major hemidesmosomal proteins
BP230 bullous pemphi antigen 1
BP180 bullous pemphi ant 2, type XVII collagen
Origin of eccrine apocrine glands ducts and pilosebaceous units
Ectodermal
What is acrosyringium
Intraepidermal spiral duct opens directly onto skin surface
Excretion of sweat is mediated by what innervation
Cholinergic (biphasic)
Decapitation secretion can be found in?
Apocrine glands
Apocrine secretion mediated by?
Adrenergic and circulating catecholamines
Sites of apocrine glands
Axillae areola anogenital EAC(ceruminous glands) eyelids (glands of moll) stroma of sebaceous nevus of Jadasshon
Phases of haur growth
Anagen, active, 3-5y, 85-90%, 0.37mm/day
Catagen, involution, 2wks
Telogen, resting, 3-5mos
What is telogen effluvium
Result of early release from anagen induced by fever surgery weight loss
Hair shape partially controlled by what gene
Trichohyalin gene
Growth of nail
0.1mm/day, 4-6mos to complete a nail plate
12-18m for toe nail
Infant vs adult dermis
Infant - small collagen bundles staib deep red, many fibroblast
Adult - few fibroblast, thick collagen bundles stain pale red
2 dermal dendritic cells in adult dermis
Factor XIIIa positive
CD34+
Major structural protein for the body
Collagen
Downregulation of which collagen mrna in photoaging
Coll I and III mrna
Type of collagen in BMZ
IV
Type of collagen in anchoring fibrils
VII
2 components of elastic fibers
Protein filaments
Elastin
Ground substance of dermis components
Sulfated acid mucopolysaccharide (chondroitin, dermatan sulfste), neutral mps, electrolytes
Minor component of dermis, accumulates in pathologic states
Hyaluronan
Vasculature in between papillary and reticular dermis
Subpapillary plexus (postcapillary venules)
Vasculature at dermal-subcutaneous interface
Lower horizontal plexus
