Skin

Thin Skin

Covers most of the body, contains hair follicles.

Thick Skin

Found on palms and soles of feet, hairless, contains the stratum lucidum.

Epidermis

Multi-layered, mainly composed of keratinocytes; the body's protective layer.

Dermis

Connective tissue layer rich in collagen and elastic fibers; provides strength and elasticity.

Hypodermis

Anchors skin to underlying tissue, allows skin movement, contains subcutaneous fat.

Stratum Basale

Deepest layer of the epidermis, site of keratinocyte production.

Stratum Spinosum

Prickly layer of the epidermis, where daughter cells from the basale layer form connections.

Stratum Granulosum

Granular layer of the epidermis where keratin formation begins and lipid release creates a waterproof barrier.

Stratum Lucidum

Layer present only in thick skin, consisting of dead flattened cells.

Stratum Corneum

Outermost layer of the epidermis containing dead cells packed with keratin.

Papillary Layer

Superficial layer of the dermis made of loose connective tissue; contains capillaries and sensory nerve endings.

Reticular Layer

Deep layer of the dermis made of dense irregular connective tissue; contains blood vessels, nerves, hair follicles, and glands.

Keratinocytes

Main epidermal cell type that produces keratin for strength and waterproofing.

Melanocytes

Cells that produce melanin mainly found in the stratum basale, providing UV protection.

Bulb (Hair)

Site of cell division in hair follicles.

Papilla (Hair)

Contains blood vessels that provide nutrients and growth signals to hair.

Sebaceous Glands

Glands associated with hair follicles, produce sebum to lubricate hair and skin.

Merocrine (Eccrine) Sweat Glands

Most abundant sweat glands, secrete sweat directly onto the skin surface.

Apocrine Sweat Glands

Sweat glands located in specific body areas that empty into hair follicles and produce a thicker secretion.