Reticulaire Dermis

In the skin tissue, right below the papillary dermis lies the reticular dermis, which accounts for around 80% of the dermal thickness.

The arteries present in the lower subcutaneous region branch into the cutaneous plexus that supplies blood to the reticular dermis and appendages present in the region, such as hair follicles, sweat glands, and sebaceous glands.

Additionally, stem cells, fibroblasts, macrophages, and mast cells are also present in this layer.

The reticular dermis also contains sensory receptors such as Pacinian corpuscles that are sensitive to pressure, and the  Ruffini corpuscles that can detect skin stretching.

The extracellular matrix of the reticular dermis primarily consists of an interwoven network of thick bundles of collagen fibers and elastic fibers. Together they make the skin strong, extendable, and elastic.

Moreover, less dense regions in the extracellular matrix and separations between the collagen bundles form cleavage or tension lines on the skin.