what is the skin that grows under the nail
Nail (anatomy) The nail bed is the skin beneath the nail plate.[8][unreliable source?] Like all skin, it is made of two types of tissues: the deeper dermis, the living tissue which includes capillaries and glands,[9][unreliable source?] and the epidermis, the layer just beneath the nail plate, which moves toward the finger tip with the plate. The epidermis is attached to the dermis by tiny longitudinal "grooves"[5] called matrix crests (cristae matricis unguis).[3][9] In old age, the nail plate becomes thinner, and these grooves become more visible.[5]
Subcutaneous tissue The subcutaneous tissue (from Latin subcutaneous, meaning 'beneath the skin'), also called the hypodermis, hypoderm (from Greek, meaning 'beneath the skin'), subcutis, or superficial fascia, is the lowermost layer of the integumentary system in vertebrates.[2] The types of cells found in the hypodermis are fibroblasts, adipose cells, and macrophages. The hypodermis is derived from the mesoderm, but unlike the dermis, it is not derived from the dermatome region of the mesoderm. In arthropods, the hypodermis is an epidermal layer of cells that secretes the chitinous cuticle. The term also refers to a layer of cells lying immediately below the epidermis of plants.