Skin Correlates

Skin Correlates

• Epidermis (5 layers) • Dermis – Papillary dermis – Reticular dermis

• Subcutaneous (Hypodermis) –

• Epidermis

• •

– Stratified squamous epithelium, keratinizing type – Thick – found on palms and soles Thin - hairy

5 layers • Stratum basale (germinativum) – Continuous mitotic activity – Consisting of a wide layer of cuboidal or columnar cells in contact with the dermis – 1 layer

• Stratum spinosum – Consisting of several rows of polyhedral cells with round nuclei •

• Stratum granulosum – Consisting of 3-5 layers of polygonal cells that gradually become flattened – The cytoplasm contains KERATOHYALINE granules

• Stratum lucidum (eosinophilic) – Composed of a thin layer transparent flattened cells – More evident in thick skin

of

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• Stratum corneum (horny layer) – Consists of many layers of flattened non-nucleated keratinized cells

Dermis • Papillary layer – Superficial thin layer of loose connective tissue beneath the epithelium •

• Reticular layer – Deeper and thicker layer which contains skin appendages, blood vessels, and nerves

Skin appendages • Hair or Hair shaft – Elongated keratinized structure derived from invagination of epidermal epithelium •

• Hair follicle –A

•

tubular invagination of the epidermis which extends down into the dermis

• Sweat gland – Appears as group of ducts bound by cuboidal cells •

• Sebaceous gland – Connected to the hair follicle, compound of polygonal cells with clear cytoplasm and centrally located nucleus •

• Arrector Pili muscle – Obliquely arranged small bundle of smooth muscle – Attached to the lower portion of hair follicle – Produces the “gooseflesh”

• Meissner’s corpuscle (tactile) – Receptor for touch – Most abundant in hairless skin of palms and soles, the figertips, lips, and nipple – Elongated ovoid bodies found in the dermal papillae (papillary) – Base of epidermis

• Pacinian corpuscle – Detection of vibration and mediate deep pressure sensation – Sliced onion-like lamellar structure located in the deep dermis and subcutaneous tissue