Dermis

Dermis

Deep part of the skin

Houses the blood supply of the epidermis

Contains sensory receptors

Anchors the epidermis in place

Divided into 2 layers:

papillary and reticular

Papillary Layer

Superficial layer of the dermis

Makes up about 20% of the depth of the dermis

Made of loose connective tissue

At the dermis-epidermis junction, special collagen fibers extend into the basement membrane to anchor the epidermis

Repetitive trauma disrupts these fibers and causes a fluid-filled pocket called a blister

The surface of the papillary layer folds into projections that push into the epidermis called Dermal Papillae

Dermal Papillae

Provide blood supply to the epidermis

House Tactile (Meissner) Corpuscles, which respond to light touch, and distinguish shape and texture of objects (Numerous in fingertips, lips, face, and external genitalia)

Reticular Layer

Deep layer of the dermis

Made of dense irregular connective tissue, which strengthens the dermis and allows it to stretch, and pockets of adipose tissue

Blood vessels, sweat glands, hairs, sebaceous glands, and sensory receptors, including Lamellated (Pacinian) Corpuscles, which respond to deep pressure and vibration, are prominent

Skin Markings

Interactions between the epidermis and dermis are visible as small lines in the epidermis

Most obvious are on the thick skin because dermal papillae are prominent and arrange into Dermal Ridges

The epidermis then indents to produce Epidermal Ridges that occur in patterns unique to each individual

Sweat pores open along these ridges and leave a Fingerprint on surfaces

Gaps between collagen bundles in the reticular layer form Tension, or Cleavage Lines (Run in a circular pattern in the neck and trunk and longitudinally in the head and limbs)

Flexure Lines are deep creases found on areas such as the palms

Wrinkles

Result from age-related decreases in collagen and elastic fibers, proteoglycans, and adipose tissue in the dermis

Exposure to UV radiation and cigarette smoking accelerate formation of wrinkles

The appearance of wrinkles can be diminished by:

Botox®, fillers, peels, and topical creams

Botox

contains a bacterial toxin that paralyzes facial muscles for 4-6 months, causing the overlying skin to appear smoother

Fillers

Fillers containing adipose tissue, collagen, and/or proteoglycans are injected into wrinkles to temporarily “fill” them

Peels

use lasers, chemicals, or abrasion to remove the epidermis and superficial dermis to cause formation of new, hopefully firmer, skin

Topical Creams

contain ingredients that claim to reduce the appearance of wrinkles

however, most creams, particularly nonprescription products, have little effect on wrinkles