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stratum malpighii(1) Basal layer of epidermis; stratum basale epidermidis [NH3].
(2) Germinative layer of epidermis, see there.
The inner layer of the epidermis. It was first seen with low magnification and described in the 1600s by Marcello Malpighi. It includes both the stratum germinativum and stratum spinosum of today's nomenclature.
See also: stratum
stratum granulosum; stratum malpighii enzymically active, partly keratinized cells; forms the suprabasal epidermal layer, between stratum spinosum and stratum corneum Table 1
|Epidermis||Stratified squamous epithelium formed from keratinocytes|
Basal layer: keratinocytes linked by desmosomal and hemidesmosomal and filamentous connections (cytoskeleton; prevents shear)
Spinous layer: keratinocytes shrink, retaining contact only at desmosomes and hemidesmosomes
Granular layer: keratinocytes secrete complex lipids which act as a semipermeable skin barrier
Corneal layer: cell and contents have become keratin to form squames moved towards the exterior
Melanocytes: lie between keratinocytes; secrete pigment and protect keratinocyte nuclei from ultraviolet radiation
Merkel cells: sensory cells
Langerhans cells: within spinous layer; antigen-presenting cells
|Basement membrane zone||Collagen, hemidesmosomes, laminin which aid adhesion of epidermis to dermis; dysfunctional in disease such as epidermolysis bullosa|
|Dermis||Mesodermal tissue containing blood vessels, nerve, muscle, skin appendages (sweat glands, sebaceous glands, hair follicles), immune cells (histamine-releasing mast cells) in a matrix of collagen, elastin and hyaluronic acid|
|Subcutaneous layer||Adipose tissue, blood vessels and nerves, acting as an insulating layer|