vascular ring — any of various developmental anomalies in which the aortic arches encircle the trachea and esophagus, sometimes compressing them … Medical dictionary
ring necrosis — noun : a browning of the vascular ring in stems or tubers (as that characteristic of fusarium wilt and a form of necrosis of the potato caused by frost) … Useful english dictionary
ring-canal — ringˈ canal noun 1. A circular canal within the rim of a jellyfish 2. A circular vessel of the water vascular system of echinoderms • • • Main Entry: ↑ring … Useful english dictionary
ring rot — noun disease of tomatoes and potatoes and tobacco etc caused by the bacterium Pseudomonas solanacearum • Syn: ↑ring disease, ↑tobacco wilt • Hypernyms: ↑brown rot * * * noun 1. : decay in a log following closely the annual rings 2 … Useful english dictionary
ring — 1. A circular band surrounding a wide central opening; a r. shaped or circular structure surrounding an opening or level area. SYN: anulus [TA]. 2. The closed ( i.e., endless) chain of atoms in a cyclic compound; commonly used for “cyclic” or… … Medical dictionary
ring rot — Plant Pathol. a disease of potatoes, characterized by wilted foliage and rotting of the ring of vascular bundles in the tubers, caused by a bacterium, Corynebacterium sepedonicum. [1900 05, Amer.] * * * … Universalium
ring block — a circumferential ring of local anaesthetic solution used to block the nerves of a digit for purposes of minor surgery (see nerve block). Precautions are necessary to avoid vascular damage leading to gangrene … Medical dictionary
ring block — a circumferential ring of local anaesthetic solution used to block the nerves of a digit for purposes of minor surgery (see nerve block). Precautions are necessary to avoid vascular damage leading to gangrene … The new mediacal dictionary
ring canal — 1. (CNIDARIA: Hydrozoa) A circular canal around the margin of the umbrella into which the radial canal join as part of the gastrovascular system. 2. (ECHINODERMATA) A circular part of the water vascular system encircling the esophagus … Dictionary of invertebrate zoology
lower vascular plant — ▪ biology Introduction formerly pteridophyte, also called vascular cryptogam, any of the spore bearing vascular plants, including the ferns, club mosses, spike mosses, quillworts, horsetails, and whisk ferns. Once considered of the… … Universalium
