Layers of the Integument and Subcutaneous layer

Stratum lucidum

2-3 layers of anucleate, dead cells; seen only in thick skin (palms of hands and soles of feet)

Stratum granulosum

3-5 layers of keratinocytes with distinct granules in the cytoplasm: keratinization begins in this layer

Subcutaneous layer

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

Layers of the Dermis

Papillary layer Reticular layer

Reticular layer

Deeper layer of dermis; dense irregular connective tissue surrounding blood vessles, hair follicles, nerves, sweatglands, and sebaceous glands

Stratum basale

Deepest , single layer of cuboidal to low columnar cells in contact with basement membrane; mitosis occurs here; contains keratinocytes. Melanocytes, and tactile cells

Layers of the Integument and Subcutaneous layer

Integument: Epidermis & Dermis No specific layers in the Subcutaneous layer

Papillary layer

More superficial layer of the dermis; composed of areolar connective tissue; forms dermal papillae

Stratum corneum

Most superficial layer of the epidermis; 20-30 layers of dead, flattened, anucleate, keratin-filled keratinocytes

Stratum spinosum

Several layers of keratinocytes attached to neighbors by desmosomes; epidermal dendritic cells present

Layers of the Epidermis

Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale