Dermis

Dermis

underlies the epidermis and is mostly strong, fibrous connective tissue (vascular)

Two layers of dermis

Papillary and Reticular

Dermal papillae

Areolar connective tissue in dermis sends projections into epidermis.

Dermal papillae contains

capillary loops, free nerve endings, and touch receptors

Friction ridges

Epidermal ridges lie on top of dermal ridges, which enhance gripping ability and touch sensation

fingerprint

Sweat duct openings along the crests of friction ridges

Reticular Layer of dermis

80% of the dermis consists of dense irregular connective tissue. With elastic and collagen fibers, it binds water and keeps skin hydrated.

Cutaneous plexus

network of blood vessels between reticular layer and hypodermis

Cleavage (tension) lines

Separations between collagen fiber bundles in the reticular dermis. Run circularly around the trunk and longitudinally in the limbs.

Flexure lines

Reticular layer dermal folds, visible on hands, wrists, fingers, soles, and toes, cause deep creases due to skin’s inability to slide easily.

striae “stretch marks”

Extreme stretching of skin can cause dermal tears, leaving silvery white scars

blisters

fluid-filled pockets that separate epidermal and dermal layers

The dermis contains

nerves, blood vessels, lymphatic vessels, epidermal hair follicles, oil glands, and sweat glands