lacunas

Lacuna, and its plural lacunae, is a term derived from Latin meaning "gap" or "hollow." In scientific usage it denotes a small space, cavity, or interval within a structure, organ, or text, as opposed to a solid, continuous mass.

In anatomy and histology, lacunae are microscopic cavities that house living cells. In bone, osteocytes sit in lacunae within the mineralized matrix and connect through canaliculi. In cartilage, chondrocytes occupy lacunae embedded in the extracellular matrix. The arrangement supports nutrient diffusion and mechanical function, and lacunar remodeling can occur with age or disease.

Lacunar infarct is a medical term for a small, deep ischemic stroke caused by occlusion of penetrating brain vessels. It commonly affects subcortical regions such as the internal capsule or thalamus and is associated with chronic hypertension and diabetes; the clinical presentation and prognosis vary depending on location and extent.

In textual criticism and archaeology, lacunae refer to missing portions in manuscripts, inscriptions, or archival records due to damage, loss, or decay. Editors document lacunae and may attempt reconstruction from context or related texts.

In geology and stratigraphy, lacunae describe hiatuses in the sedimentary record—intervals of non-deposition or erosion. Recognizing lacunae is important for dating, correlating layers, and interpreting site formation histories.