Retraction Ring: From 1 Different Sources
a depression in the uterine wall marking the junction between the actively contracting muscle fibres of the upper segment of the uterus and the muscle fibres of the lower segment. This depression is not always visible and is normal. In obstructed labour (e.g. contracted pelvis or malposition of the fetus resulting in shoulder presentation), the muscle fibres of the upper segment become shorter and thicker; the muscle fibres of the lower segment, on the other hand, become elongated and thinner. The junction between the two becomes more distinct as it rises into the abdomen from the pelvis. This abnormal ring is known as Bandl’s ring and is a sign of impending rupture of the lower segment of the uterus, which becomes progressively thinner as Bandl’s ring rises upwards. Immediate action to relieve the obstruction is then necessary, usually in the form of Caesarean section.
A local anaesthetic agent (see ANAESTHESIA) injected into the circumference of the base of a digit. It numbs the nerves of the ?nger or toe and so permits minor surgery to be performed. Care must be taken to avoid damage to local blood vessels which can lead to GANGRENE.... ring block
Colloquial term for Hapalochlaena spp.... blue-ringed octopus
Reserving money to be spent for a particular service, such as grants to local authorities.... ring-fencing
See tinnitus.... ringing in the ears
see retraction ring. [L. Bandl (1842–92), German obstetrician]... bandl’s ring
a ring designed to be inserted into the peripheral tissue of the cornea in order to alter the curvature of the corneal surface. It is undergoing trials to assess its ability to correct errors of refraction. In myopia (short-sightedness), for example, the ring would be required to stretch the corneal tissue peripherally and thus flatten the central corneal curvature in order to correct the myopia.... corneal ring
a deposit of iron in the form of a ring in the epithelium of the cornea, which is seen, for example, around the base of the ‘cone’ of the cornea in *keratoconus. It is best visualized using cobalt blue light. [B. Fleischer (1848–1904), German physician]... fleischer ring
a watertight adherent ring placed around an intestinal *stoma and incorporating a flange to which a disposable plastic bag could be attached. It was the forerunner of modern disposable stoma bags.... hollister ring
a brownish-yellow ring in the outer rim of the cornea of the eye. It is a deposit of copper granules and is diagnostic of *Wilson’s disease. When well developed it can be seen by unaided observation, but faint Kayser-Fleischer rings may only be detected by specialized *slit-lamp ophthalmological examination. [B. Kayser (1869–1954), German ophthalmologist; B. Fleischer (1848–1904), German physician]... kayser–fleischer ring
n. 1. (in obstetrics) the state of uterine muscle fibres remaining shortened after contracting during labour. This results in a gradual progression of the fetus downwards through the pelvis. The basal portion of the uterus becomes thicker and pulls up the dilating cervix over the presenting part. 2. (in dentistry) the drawing back of one or more teeth into a better position by an *orthodontic appliance. 3. (in dentistry) the stretching of facial tissues to expose only the teeth during dental photography.... retraction
n. (in anatomy) see annulus.... ring
(Ringer’s mixture) a clear colourless *physiological solution of sodium chloride (common salt), potassium chloride, and calcium chloride prepared with recently boiled pure water. The osmotic pressure of the solution is the same as that of blood serum. Ringer’s solution is used for maintaining organs or tissues alive outside the animal or human body for limited periods. Sterile Ringer’s solution may be injected intravenously to treat dehydration. [S. Ringer (1835–1910), British physiologist]... ringer’s solution
a ringlike constriction in the lower part of the gullet (oesophagus). The cause is unclear. Patients may be asymptomatic or experience episodic difficulty in swallowing. Diagnosis is made at gastroscopy or *barium swallow. Antisecretory agents and endoscopic balloon dilatation are reserved for symptomatic patients. [R. Schatzki (20th century), German-born US physician]... schatzki ring
the ring of lymphoid tissue formed by the *tonsils. [H. W. G. von Waldeyer (1836–1921), German anatomist]... waldeyer’s ring
a ringlike opacity on the posterior vitreous surface, arising as a result of a posterior *vitreous detachment. It is seen as a ring-shaped *floater.... weiss ring
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