stratum lucidum

{{Short description|Thin layer of dead skin cells}}

{{for|the layer in the brain|Stratum lucidum of hippocampus}}

File:Epidermal layers.svg. Stratum lucidum labeled near center.]]File:Skinlayers.png

The stratum lucidum (Latin, 'clear layer') is a thin, clear layer of dead skin cells in the epidermis named for its translucent appearance under a microscope. It is readily visible by light microscopy only in areas of thick skin, which are found on the palms of the hands and the soles of the feet.{{cite book|title=Acute and Chronic Wounds: Current Management Concepts|url=https://books.google.com/books?id=80rSnSZWFhMC&pg=PA41|year=2007|publisher=Mosby Elsevier|isbn=978-0-323-03074-8|pages=41}}{{cite book|last=Narayan|first=Roger|title=Biomedical Materials|url=https://books.google.com/books?id=wyFYTCus8OgC&pg=PA376|date=20 June 2009|publisher=Springer Science & Business Media|isbn=978-0-387-84872-3|page=376}}

Located between the stratum granulosum and stratum corneum layers, it is composed of three to five layers of dead, flattened keratinocytes.McGrath, J.A.; Eady, R.A.; Pope, F.M. (2004). Rook's Textbook of Dermatology (Seventh Edition). Blackwell Publishing. Pages 3.8. {{ISBN|978-0-632-06429-8}}.Tortora, Gerard; Derrickson, Bryan; Principles of Anatomy and Physiology (2009)152 John Wiley & Sons Inc, Hoboken, NJ {{ISBN|978-0-470-08471-7}}. The keratinocytes of the stratum lucidum do not feature distinct boundaries and are filled with eleidin, an intermediate form of keratin. They are surrounded by an oily substance that is the result of the exocytosis of lamellar bodies accumulated while the keratinocytes are moving through the stratum spinosum and stratum granulosum.{{citation needed|date=May 2012}}

The thickness of the stratum lucidum is controlled by the rate of mitosis (division) of the epidermal cells. Melanosomes in the stratum basale determine the darkness of the stratum lucidum.