what is the upper most layer of skin
Epidermis The epidermis is the outermost of the three layers that make up the skin, the inner layers being the dermis and hypodermis.[1] The epidermis layer provides a barrier to infection from environmental pathogens[2] and regulates the amount of water released from the body into the atmosphere through transepidermal water loss.[3] The epidermis is composed of multiple layers of flattened cells[4] that overlie a base layer (stratum basale) composed of columnar cells arranged perpendicularly.
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.[3] 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.