isthmus


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isthmus

(ĭs`məs), narrow neck of land connecting two larger land areas. Since it commands the only land route between two large areas and is on two seas, an isthmus has great strategical and commercial importance and is a favorable situation for a city. In modern times many isthmuses have been cut through by canals to eliminate the necessity of land transport. The most important isthmuses are the Isthmus of Panama, connecting Central and South America, and the Isthmus of Suez, joining Asia and Africa. Canals were dug through both of these. The Isthmus of Corinth between the Morea peninsula and central Greece also has a canal.
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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Isthmus

 

a relatively narrow strip of land that connects larger land areas, such as two continents (Isthmus of Suez, Isthmus of Panama) or a peninsula and the mainland (Perekop Isthmus). Some isthmuses, such as the Karelian Isthmus, separate two bodies of water.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

isthmus

[′is·məs]
(biology)
A passage or constricted part connecting two parts of an organ.
(geography)
A narrow strip of land having water on both sides and connecting two large land masses.
(mathematics)
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

isthmus

1. a narrow strip of land connecting two relatively large land areas
2. Anatomy
a. a narrow band of tissue connecting two larger parts of a structure
b. a narrow passage connecting two cavities
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
The blood supply of the isthmus also has some variability: it may receive blood from the main renal artery, from the abdominal aorta (originating above or below the isthmus), the common iliac artery or the inferior mesenteric artery (Mano et al., 2016).
Europaeus-Ayrapaa presented in his work a three-part classification for the pottery of the Stone Age from Finland and the Karelian Isthmus. The system includes Early (Ka I or Sperrings), Typical (Ka II or TCW) and Late Comb Ware (Ka III or LCW).
Various locations of the base of pyramidal lobe generally require careful dissection of both the pretracheal and the prelaryngeal regions from the upper border of the isthmus up to the upper border of the thyroid cartilage in most of the patients and sometimes up to the hyoid bone.
Long-term outcomes after catheter ablation of cavo-tricuspid isthmus dependent atrial flutter: a metaanalysis.
Although the incidence of thyroid isthmus agenesis has been reported to range between 0.5% and 10%, the precise incidence rate is unknown (4, 5).
* Graft isthmus artery: End-to-end anastomosis to the recipient internal iliac artery.
With regard to unfilled parts of the root canal system, an unfilled isthmus (27.5%), an unfilled main canal (18.8%) or an unfilled isthmus with unfilled canals (11.5%) were the main findings (Table 3).
The clinical causes of failure were categorized as follows: (1) leaky canal: a gap between the previous root filling and the dentin or obvious leakage after methylene blue staining; (2) anatomical complexity: isthmus between the two canals filled or an apical ramification that had not been treated; (3) missing canal: untreated canal regardless of the presence of an isthmus; (4) underfilling: fillings more than 2 mm short of the apex in preoperative radiographs; (5) over-filling: excess root filling; (6) iatrogenic problem: perforation, transportation, or file separation; (7) calcified canal; and (8) calculus.
A hard lump of size 20 x 15 mm and unclear border could be seen on the isthmus of thyroid during surgery.
The winners of the categories 12.6 and 14 will have the unique opportunity to travel for free with Aegean Airlines and take part in the final race of the Seventh Hellenic SUP CUP 2017, the crossing of Isthmus of Corinth.
The 337-km highway and the rail line for the Ferrocarril del Sureste in the Isthmus of Tehuantepec are part of the Mexican government's grand plan to improve the country's transportation infrastructure, including port facilities.
The association between RAI treatment failure and various clinical parameters including age, sex, height, weight, body mass index (BMI), thyroid gland volume, and isthmus length on ultrasonographic images, thyroid function and thyroid autoantibody levels before treatment, dose of RAI, RAI uptake rate, and serum selenium and 25-hydroxycholecalciferol levels was analyzed.