part of has part adipose tissue hypodermis vertebrate hypodermis subcutaneous tissue Lowermost layer of the integumentary system in vertebrates. Types of cells that are found in the hypodermis are fibroblasts, adipose cells, and macrophages. It is derived from the mesoderm, but unlike the dermis, it is not derived from the dermatome region of the mesoderm. The hypodermis is used mainly for fat storage[WP]. sub-tegumental tissue subcutis superficial fascia tela subcutanea hypoderm subtegumental tissue integument mesoderm-derived structure loose connective tissue integumentary system layer