Dermatology PDF

Dermatology General Skin: largest organ in the body Barrier against infection Prevents water loss Epidermis: keratinocytes (squamous epithelial cells) Stratum basale Stem cells Stratum spinous Desmosomes form spines Stratum granulosum...

Dermatology General Skin: largest organ in the body Barrier against infection Prevents water loss Epidermis: keratinocytes (squamous epithelial cells) Stratum basale Stem cells Stratum spinous Desmosomes form spines Stratum granulosum Keratohyalin granules > Form keratin filaments Stratum lucid Clear layer of dead skin cells Stratum corneum Anucleated cells, filled with keratin filaments Dermis: connective tissue, vessels – Connective tissue – Blood vessels Hypodermis: subcutáneanous fat Dermatopathology (skin biopsies) Term Definition Pathologies associated Hyperkeratosis Thickening of stratum Psoriasis, callus corneum (excess keratin) Parakeratosis Hyperkeratosis + Psoriasis, retained nuclei in malignancies stratum corneum (hyperproliferation) Hypergranulosis Increased thickness of Lichen planus stratum granulosum Spongiosis Fluid accumulation of Eczema  retained nuclei in malignancies stratum corneum (hyperproliferation) Hypergranulosis Increased thickness of Lichen planus stratum granulosum Spongiosis Fluid accumulation of Eczema epidermis Acantholysis Loss of connections Pemphigus vulgaris between keratinocytes (loss of desmosomes), rounded keratinocytes detached, floating freely Acanthuses Diffuse epidermal hyperplasia, elongated rete ridges (spinous layer thickening)