A mycorrhiza (Greek: Î¼ÏÎºÏÏ, mykÃ³s, fungus, and ÏÎ¯Î¶Î±, riza, root, pl. mycorrhizae or mycorrhizas) is a symbiotic association between a fungus and the roots of a vascular host plant. The term mycorrhiza refers to the role of the fungi in the plants' rhizosphere, its root system. Mycorrhizae play important roles in soil biology and soil chemistry.
The dermis consists of a papillary and a reticular layer which serve to protect and cushion the body from stress and strain. Differentiate among the regions of the dermis and the hypodermis. The dermis is divided into a papillary region and a reticular region.
These have two functions. First, they help adhesion between the dermal and epidermal layers. Second, in areas of thick skin like this, they provide a large surface area, to nourish the epidermal layer. Don't forget the epidermis is a stratified squamous epithelium, so it does not have its own blood supply.