ABSTRACT
E. Hair follicles, sebaceous glands, and eccrine sweat glands derive from ectoderm. The ectoderm forms the epidermis and the epidermal appendages. This has clinical relevance to the healing process in partial-thickness wounds as the ectodermally derived skin appendages such as hair follicles, eccrine and apocrine sweat glands, and sebaceous glands are epithelial lined and provide a source of keratinocytes for reepithelialization. This knowledge also helps to understand how certain conditions present. For example, the fact that skin and neural tissue share embryologic origin explains why patients with neurofibromatosis develop both skin and nerve tissue tumors. The mesodermal derivatives are also clinically relevant to plastic surgery as this embryologic layer forms bone, cartilage, muscle, connective tissue, and blood vessels. The endoderm has less applicability to plastic surgery as it forms the lining of the gastrointestinal and respiratory tracts and the digestive organ parenchyma.
