Expansion
Papillary dermis is fine and vascular; reticular dermis is dense and strong
Expansion
Papillary dermis (superficial)
- Loose connective tissue with fine type III and I collagen
- Dermal papillae interdigitating with epidermal rete ridges, increasing adhesion and surface area for nutrition
- Rich capillary loops, and Meissner corpuscles for light touch
Reticular dermis (deep)
- Dense irregular connective tissue with thick type I collagen and elastic fibres
- Provides tensile strength; the layer used for leather
- Contains adnexae: hair follicles, sebaceous and sweat glands
- Pacinian corpuscles for vibration and pressure
Beneath lies the hypodermis (subcutis) of adipose tissue.
Clinical applications follow directly
- Burn depth: superficial partial thickness heals from surviving adnexae in days; deep partial thickness heals slowly with scarring; full thickness destroys all adnexae and requires grafting
- Split thickness grafts take epidermis and superficial dermis, so the donor site heals from remaining adnexae
- Striae result from reticular dermal collagen rupture
- Loss of rete ridges with ageing reduces adhesion, causing skin fragility and blistering