The hypodermis, also called the hypoderm, subcutaneous tissue, or superficial fascia's the lowermost layer of the integumentary system in vertebrates. Types of cells that're found in the hypodermis are fibroblasts, adipose cells, and macrophages. It's derived from the mesoderm, but unlike the dermis, it isn't derived from the dermatome region of the mesoderm. In arthropods, the hypodermis's an epidermal layer of cells that secretes the chitinous cuticle. The term also refers to a layer of cells… (More on Hypodermis)