Annulus (or anulus) or annular indicates a ring- or donut-shaped area or structure. It may refer to:
Human anatomy Anulus fibrosus disci intervertebralis, spinal structure Annulus of Zinn, a.k.a. annular tendon or anulus tendineus communis, around the optic nerve Annular ligament (disambiguation) Digitus anularis, a.k.a. ring finger Anulus ciliaris, a.k.a. ciliary body Anulus femoralis, a.k.a. femoral ring Anulus inguinalis superficialis, a.k.a. superficial inguinal ring Anulus inguinalis profundus, a.k.a. deep inguinal ring Anuli fibrosi cordis, a.k.a. fibrous rings of heart Anulus umbilicalis , a.k.a. umbilical ring
Biology
Annulus (botany), structure on fern and moss sporangia Annulus (mycology), structure on mushroom Annulus (zoology), an external circular ring
Other Annulus (construction), outer gear ring in an epicyclic gearing Annular lake, a ring-shaped lake caused by meteor impact Annulus (mathematics), the shape between two concentric circles Annulus (firestop), site of construction issue Annular piston, a ring-shaped piston Annulus (well), void between concentric cylinders Annular blowout preventer, device for sealing oil and gas wells Annulation, type of ring-producing chemical reaction
See also
Annulet (disambiguation) Annular eclipse Annular tropical cyclone Annular combustor, design option in engine Ring (disambiguation)