epidérmicos

Epidérmicos is a term used in biology and medicine to describe structures, tissues, or processes related to the epidermis, the outermost layer of the skin in animals and, in plants, the outer protective layer of aerial organs. The word derives from epi- “upon” and derma “skin.”

In animals, the epidermis is a stratified squamous epithelium carried by a basement membrane; keratinocytes predominate, with melanocytes, Langerhans cells and Merkel cells interspersed. It comprises layers such as basale, spinosum, granulosum and, in thick skin, lucid and corneum. Its main functions are to form a barrier, minimize water loss, provide immune defense, and mediate sensation. In plants, the epidermis is the outer protective layer of leaves, stems, and fruits, usually covered by a cuticle; specialized cells include guard cells and trichomes that regulate gas exchange and deter herbivory.

Development and pathology: Epidermal cells arise from the embryonic ectoderm in animals; renewal is by basal cell proliferation and differentiation. Disorders affecting the epidermis include dermatitis, psoriasis, bullous diseases, and epidermal cancers such as basal cell carcinoma, squamous cell carcinoma, and melanoma. Diagnosis relies on histology, dermoscopy, and immunohistochemistry; treatment depends on the condition.

Plant epidermis: In plants, the epidermis is typically a single cell layer in non-woody tissues; the cuticle reduces water loss; guard cells regulate stomatal opening; and trichomes deter herbivory and contribute to microclimate regulation. Epidermal traits are used in botany and agronomy for taxonomy, physiology, and crop improvement.