Jan 24, 2019
Integumentary System | Biological Sciences
The integument or the skin forms the external covering of a vertebrate. It is continuous with the mucous membrane lining the mouth, rectum, nostrils, eyelids, and the opening of urinogential ducts. The skin comes in contact with the environment, and the type of environment whether terrestrial or equatic, influences the character of the skin. The vertebrate skin differs from that of invertebrates in having two layers, an outer epidermis derived from the ectoderm, an and inner dermis or corium formed from the mesenchyme of the dermatomes, the relative amount of the two layers veries with the environment.