Skin layers and the subcutaneous layer

Stratum lucidum (Descriprion)

2-3 layers of anucleate, dead cells; seen only in thick skin

Stratum granulosom (Description)

3-5 layers of keratinocytes with distinct keratohyaline granules

Dermis (Specific Layers)

Papillary layer Reticular layer

Epidermis (Specific Layers)

Stratum Corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale

Subcutaneous layer (Specific Layers)

no specific layers

Reticular layer (Description)

Deeper layer of dermis; dense irregular connective tissue surrounding hair follicles, sebaceous glands and sweat glands, nerves, and deep plexus of blood vessels extending into subcutaneous layer

Stratum basale (Description)

Deepest, single layer of cuboidal to low columnar cells in contact with basement membrane; mitosis occurs here; melanocytes and merkel cells also

Papillary layer (Description)

More superficial layer of dermis; composed of areolar connective tissue; forms dermal papillae; contains subpapillary vascular plexus

Stratum corneum (Description)

Most superficial layer; 20-30 layers of dead, flattened, anucleate, keratin-filled keratinocytes; protects against friction and water loss

Subcutaneous layer (Description)

Not considered a part of the integument; deep to dermis; composed of areolar and adipose connective tissue

Stratum spinosum (Description)

Several layers of keratinocytes all joined by desmosomes; Langerhans cells present