Fibrillaire

Fibrillaire is an adjective used in French to describe anything Relatif to or composed of fibrilles, which are slender, thread-like filamentous structures. In biology, fibrils are polymeric filaments formed by proteins or other polymers and constitute many cellular and extracellular components. The term is applied across disciplines to convey a fibrous, elongated morphology rather than a homogeneous mass.

In histology and anatomy, fibrillar organization is common: muscle fibers are organized into myofibrils; neurons contain neurofibrils; connective tissues contain collagen fibrils arranged in networks. Descriptions such as architecture fibrillaire or dépôts fibrillaires indicate a tissue or lesion where filaments or filiform deposits predominate.

In medicine and pathology, fibrillaire deposits or formations may be noted in certain diseases, for example fibrillar protein aggregates such as amyloid fibrils, which adopt a filamentous morphology. The term can also appear in tumor description, as in stroma fibrillaire, indicating a fibrous, filamentous tissue component surrounding a lesion.

In materials science or botany, fibrillaire describes natural or synthetic fibrous structures, such as collagen fibrils, cellulose microfibrils, or other networks composed of nanoscale or microscale filaments. The word remains largely descriptive, distinguishing fibrous texture from amorphous or non-filamentous forms.

Etymology: derived from fibrille, fibril, from Latin fibra, fiber. The usage is widespread and primarily serves to emphasize a filamentous architecture or composition.