cuticle

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Related to cuticula: cuticular

cuticle

1. dead skin, esp that round the base of a fingernail or toenail
2. another name for epidermis
3. any covering layer or membrane
4. the protective layer, containing cutin, that covers the epidermis of higher plants
5. the hard protective layer covering the epidermis of many invertebrates

Cuticle

 

(1) In animals, a solid formation on the surface of cells of epithelial tissue. In invertebrates, a derivative of cells of the single-layered integumental epithelium, or hypodermis. The functions of the cuticle are chiefly protective and supportive. In worms and arthropods, it forms a tough body covering. The composition of cuticle includes chitin (which, together with mineral substances and proteins, provides mechanical strength) and lipids (which make the cuticle impervious to water).

In vertebrates, which have a multilayered integumental epithelium to perform the protective function, the cuticle is found mainly on the surface of the epithelial cells that line the viscera (the intestines, the air passages of the respiratory organs, parts of the uriniferous tubules of the kidneys, and the urinary tracts). Each cell has its own cuticle, which is represented completely by the microvilli (the surface of a single cell of the small intestine in man having as many as 2,000). The activity of certain enzymes (for example, alkaline phosphatase, invertases, and maltases) has been discovered in the cuticle, testifying to the active participation of the cuticle in the functional activities of the organs.

(2) In plants, the cuticle is the thin protective film covering the epidermis of the leaves and stems and consisting of cutin. The cuticle is an unstructured formation, lacking corpuscular or fibrillar elements. It is resistant to chemical influences. It is absent in the underwater organs of aquatic plants, and it is poorly developed in plants that live in shade or damp soil. It is especially well developed in plants that must limit transpiration. The smooth, shiny cuticle of the leaves of tropical plants reflects some of the sunlight striking the plants and serves as a shield against excessive insolation. In many xerophytes, the protective properties of the epidermis are reinforced beneath the cuticle by a cuticular layer, which consists of a mixture of polysaccharides, cutin, and waxes. In the majority of xerophytes, the cuticular layer holds pale yellow pigments, which help make the cell wall impenetrable to ultraviolet rays.

M. E. ASPIZ

cuticle

[′kyüd·ə·kəl]
(anatomy)
The horny layer of the nail fold attached to the nail plate at its margin.
(biology)
A noncellular, hardened or membranous secretion of an epithelial sheet, such as the integument of nematodes and annelids, the exoskeleton of arthropods, and the continuous film of cutin on certain plant parts.
References in periodicals archive ?
Caption: FIGURA 1: Eletromicrografia de varredura da testa de sementes intactas de garapa (testemunha), apresentando rachaduras ([right arrow]) em forma de placas na cuticula.
anisopliae (figura 1), comienza con la adhesion de las conidias del hongo a la cuticula de la garrapata y su colonizacion inmediata, proceso que dura alrededor de 24 horas (Kurtti y Keyhani, 2008) y que consiste en la identificacion de un hospedero sensible para germinar y comenzar a formar hifas hasta crear una estructura denominada apresorio (Leemon y Jonsson, 2012).
Porque nao e o artista o responsavel pela missao que professa, mas a propria vida que o aprisiona nessa cuticula.
2009), analizaron el impacto del proceso de muda y las lesiones en la cuticula de los camarones sobre la susceptibilidad a WSSV, mediante las vias de infeccion intramuscular o por inmersion.
Cuticula toracica ocre, mesonoto con 3 fajas negras, la mediana se extiende desde el foramen occipital hasta el medio de la postsutura; las laterales desde la linea posthumeral hasta antes del callo post alar, ligeramente separadas de la mediana en la presutura y contiguas con esta en la postsutura.
It has been speculated that the function of the glands of gizzard was to form the cuticula, which replaced the defense function as the mucins in the proventriculus.
Los escleritos triangulares estan presentes solo en larvas afidofagas y en Microdontini y tienen como funcion anclarse en la cuticula de la presa durante el proceso de alimentacion evitando que escapen (Rotheray 1993).
El revestimiento del mesenteron de origen epitelial, presenta un aspecto irregular, digitiforme, principalmente debido a la ausencia de cuticula y secrecion de mucus que ayuda a la lubricacion del alimento durante su paso por el ventriculo, ademas de la proteccion de las celulas de sus paredes a traves de la membrana peritrofica (Bolognesi et al 2008).
1A, D, G, E, G y H); la cuticula y las paredes de las celulas epidermicas son gruesas y estas ultimas con contenido de origen fenolico en las cavidades (Figs.
por lo cual se hospitaliza para manejo antibiotico con cefepime ajustado a funcion renal, a la exploracion fisica campos pulmonares con fremito normal, murmullo vesicular disminuido, pectoriloquia infraescapular derecha, unas en miembros superiores con presencia de melanoniquia (Figura 1), unas en miembros inferiores de color amarillo-verdoso oscuro, con engrosamiento de la curvatura transversal y longitudinal, ausencia de cuticula y lunula (Figura 2).
Un dia antes de cosechar se extrajeron las jaulas, se contaron los camarones de cada lote, se pesaron las biomasas y se obtuvo la media de peso de cada lote, se procedio a inyectar solucion Davidson (33 por ciento de alcohol etilico al 95 por ciento, 22 por ciento de formalina al 100 por ciento, 11,5 por ciento de acido acetico glacial y 33,5 por ciento de agua destilada) a los camarones, en hepatopancreas, cefalotorax, 2, 4 y 6 segmentos abdominales (Lightner, 1996), se les realizo un corte longitudinal lateral a todo lo largo de la cuticula y se colocaron en frascos (uno para cada lote) con solucion Davidson, etiquetados para su identificacion (Lightner, 1996), se trasladaron al laboratorio, para realizar estudios histopatologicos y conteo de gregarinas.