PHAR 303 Lecture Notes - Lecture 18: Lawsone, Malnutrition, Methylmercury
29 Mar 2017
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Phar 303 lecture 18: skin and eyes (zorychta) Epidermis: uppermost layer, high turnover of cells (continuous: has deep invaginations into the dermis rete ridges. Terminal differentiation from base to surface is about 4wks. Dead cells at surface are held together by lipids in between them. Melanocytes make melanin, packaged into granules and inserted in keratinocytes. Spinosum langerhans cells (dcs in the skin) and merkel cells (mechanoreceptors) Granulosum keratinocytes secrete lipids into the intercellular space moisture conservation. Corneum flattened dead cells, always shedding, 80% keratin content, forms physical barrier of the skin. Acid mantle: thin layer of acidic oils (ph 4-6) on skin surface which protects from alkaline compounds, bacteria and fungi. Compromised sc leads to enhanced uptake, can be caused by an abrasion or wound: leads to high water content. Thickness of sc affects penetration: thick sc on palms and soles of feet resistance to absorption of toxicants, thin sc behind ears and on the eyelids (upper arms too)
