| 释义 |
ep·i·der·mis
\ˌepəˈdərmə̇s, -də̄m-, -dəim-\ noun
(-es)
Etymology: Late Latin, from Greek, from epi- + -dermis (from derma skin, from derein to skin) — more at tear
1.
a. : the outer epithelial layer of the external integument of the animal body that is derived from the embryonic epiblast; specifically : the outer nonsensitive and nonvascular layer of the skin of a vertebrate that overlies the corium, consists of numerous layers of squamous epithelial cells of which the outer are progressively more compressed and horny, and is often modified into specialized outgrowths (as hair, feathers, nails, and hoofs)
b. : any of various animal integuments; especially : periostracum
2. : a layer of primary tissue in higher plants that is commonly one cell thick, often cutinized on its outer surface, and continuous in young plants except over the stomata, that provides protection to underlying parts against mechanical injury and desiccation, and that is largely replaced (as by periderm or exodermis) in older plants except on leaves and herbaceous stems |