scleral ring

scle·ral ring

the appearance of the sclera adjacent to the optic disc when the retinal pigment epithelium does not extend to the optic nerve.

scle·ral ring

(skērăl ring)

Scleral appearance adjacent to the optic disc when retinal pigment epithelium does not extend to the optic nerve.

ring

1. any annular or circular organ, structure or area.

2. in chemistry, a collection of atoms united in a continuous or closed chain.

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abdominal ring (external)

an opening in the aponeurosis of the external oblique muscle for the spermatic cord or round ligament. Called also external inguinal ring.

abdominal ring (internal)

an aperture in the transverse fascia for the spermatic cord or round ligament. Called also internal inguinal ring.

Bandl's ring

see bandl's rings.

ring cell

an immature granulocyte, intermediate between the myelocyte and metamyelocyte, found in the bone marrow of rats. There is a 'hole' in the nucleus.

ciliary ring

the posterior part of the ciliary body of the eye, a continuation of the choroid.

conjunctival ring

a ring at the junction of the conjunctiva and cornea.

constriction ring

a contracted area of the uterus, where the resistance of the uterine contents is slight, as over a depression in the contour of the fetus, or below the presenting part.

deep inguinal ring

an aperture in the transverse fascia for the spermatic cord or the round ligament.

docking ring

see elastrator.

femoral ring

the abdominal opening of the femoral canal through which the femoral nerve and blood vessels pass from the peritoneal cavity to the limb.

inguinal ring

see abdominal ring (above).

pancreatic ring

the ring in the pancreas that accommodates the portal vein.

ring precipitin test

see precipitin reaction.

preputial ring

the rim of the external orifice of the prepuce proper, the internal prepuce, on the penis of the horse.

retraction ring

the demarcation between the upper, contracting portion of the uterus in normal parturition and the lower, dilating part.

retraction ring (pathological)

a complication of prolonged labor marked by failure of relaxation of the circular fibers at the internal opening of the cervix, obstructing delivery of the fetus.

Schwalbe's ring

see schwalbe's ring.

scleral ring

see ring of ossicles.

stallion ring

a rubber ring fitted over the glans penis of the stallion which discourages erection and masturbation.

superficial inguinal ring

a fissure-like opening in the aponeurosis of the external abdominal oblique muscle for the spermatic cord or the round ligament.

ring test

see ascoli test.

tympanic ring

the bony ring forming part of the temporal bone at birth and developing into the tympanic plate.

umbilical ring

the orifice in the abdominal wall of the fetus for transmission of the umbilical vein and arteries.

ring vaccination

vaccination of all animals in a zone around an area in which the subject disease occurs. A preventive strategy that contains the infected population so that the eradication team has a finite target.

vascular ring

any of a number of congenital anomalies of the aortic arch and its branches, the vessels forming a ring about the trachea and esophagus that cause varying degrees of compression, vomiting and esophageal dilatation. See also persistent right aortic arch.