fissure
A fissure (medical term, from Latin fissura "column", "crack"; Pl. Fissurae ) is
- In anatomy, a natural groove or furrow on an organ surface, for example:
- in the brain ( Fissura Sylvii etc.), see cerebral cortex # folding (gyration)
- in the lungs between the lung lobes ( fissura obliqua and fissura horizontalis )
- on the liver ( Fissura ligamenti teretis and Fissura ligamenti venosi )
- Gap-shaped openings between the skull bones (e.g. orbital fissure in the orbit, petrotympanic fissure on the temporal bone)
- the grooves on the teeth, see fissure (tooth)
- in pathology:
- a tear in the skin or mucous membrane (e.g. as an anal fissure or rhagade )
- a malformation of the skin, such as the cutaneous fissure (indentation or fold over a sternum that has not grown together)
- a hairline crack in the bone ( fissura ossium , the lightest form of bone fracture )
