Annulus
Encyclopedia : A : AN : ANN : Annulus
Annulus, being the Latin for 'ring' is a term used to describe various ring-shaped objects:
- Annulus (heart), the ring-like structure on a heart valve where the valve leaflets are anchored.
- Annulus (spine), the outer wall of the invertebral disc.
- Annulus (entomology), an antennal unit in simple antennae, or a ring-like marking or structure surrounding a joint or segment.
- Annulus (ichthyology), the annual rings that form in fish scales or bone sections.
- Annulus (mycology), the "ring" on a mushroom stem.
- Annulus (astronomy), the ring of light from the visible part of the photosphere seen at the greatest extent of an annular eclipse.
- Annulus (mathematics), a ring-shaped geometric figure.
- Annulus (oil well), the tube shaped void between the drill string and the formation when drilling an oil well.
- More generally, any ring shaped object, structure, or pattern.
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