annul-, anul-

(Latin: ring)

1. Shaped like or forming a ring.
2. In mining engineering, the space between the casing and a wall of a hole or between a drill pipe and casing.
Pertaining to the aorta and the fibrous ring of the heart at the aortic orifice.
annuloplasty, anuloplasty
A plastic repair of a cardiac valve by shortening the circumference of its annulus.
annulus (s), annuluses, annuli (pl)
A ringlike structure, or any body part that is shaped like a ring; which is applied to many small ring-shaped structures; such as, parts in a plant or animal, for example, a growth ring on fish scales.

The base of a heart valve that supports the valve's leaflets is called the annulus and a ring-shaped pancreas that encircles the duodenum is an annular pancreas.

Annulus is a misspelling of the Latin anulus, "a little ring", the diminutive of the Latin anus, "a ring of more substantial size"; so, keep in mind that anulus is now the preferred spelling for any "ringlike structure" reference.

anular cartilage, cricoid cartilage
The lowermost of the laryngeal cartilages; it is shaped like a signet ring, being expanded into a nearly quadrilateral plate (lamina) posteriorly.

The anterior portion is called the arch (arcus).

anular ligament
One of a number of ligaments encircling various parts; the principal anular ligaments are those of the stapes, radius, and trachea.
1. A general anatomic nomenclature for a circular or ringlike structure; also written as annulus; however, some sources state that the spelling anulus is currently preferred.
2. In zoology, a ring-shaped structure; such as, any of the external segments of an annelid worm.
anulus ciliaris, ciliary body
A thickened portion of the vascular tunic of the eye between the choroid and the iris.

It consists of three parts or zones: orbiculus ciliaris, corona ciliaris, and ciliary muscle.

anulus iridis minor
The lesser ring of the iris; the more coarsely striated inner concentric circle on the anterior surface of the iris; also called "lesser circle of iris".
anulus iridis, border of iris, ring of iris
Either of two zones on the anterior surface of the iris, separated by a circular line concentric with the pupillary border.
anulus lymphaticus cardiae
A cardiac lymphatic ring which is a chain of lymph nodes (paracardial lymph nodes) around the cardiac opening of the stomach.
anulus ovalis, limbus fossae ovalis
A muscular ring surrounding the fossa ovalis in the wall of the right atrium of the heart.