Ductus of Arantius - Ductus of Arantius

…On the other hand, in the fetus, both nutritional intake and gas exchange are carried out through the placenta, which is located outside the body, so the state of blood circulation is significantly different from that of an adult. The main differences between fetal blood circulation and postnatal blood circulation are: (1) the heart has a foramen ovale that connects the left and right atria, (2) the pulmonary artery connects to the aorta through the duct of Bothales, so the large and small circulations are not separated, and the blood circulation in the lungs is extremely incomplete, with only enough blood circulating to supply the nutrients necessary for the development of the lungs, and (3) the umbilical vein (which has arterial blood) opens directly into the inferior vena cava through the duct of Arrantius, sending fresh blood to the heart (Figure 8). In the fetal circulatory system, only the duct of Arrantius and its branches contain pure arterial blood, and in other parts, venous blood is mixed in various proportions, but the blood circulating in the upper body is more arterial than that in the lower body. …

*Some of the terminology explanations that mention the "ductus venosus of Arantius" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…一方，胎児では栄養摂取もガス交換も体外に存在する胎盤で行われるために，血液循環の状態は成人に比べて著しく異なっている。胎児血行と出生後の血行との差異の主要点は，(1)心臓には卵円孔が存在して左右の心房が交通し，(2)ボタロ管によって肺動脈が大動脈に連絡するため，大循環と小循環とは分離されず，肺の血行はきわめて不完全で，肺の発育に必要な栄養を供給するに足る血液が循環するにすぎず，(3)臍静脈(動脈血を有する)はアランティウス静脈管によって直接に下大静脈に開口し，心臓に新鮮血を送る，という3点である(図8)。胎児循環系のなかで純粋な動脈血を有するのはただわずかにアランティウス静脈管とその分枝のみで，その他の部分では種々の割合に静脈血を混ずるが，上半身を巡る血液は，下半身のものに比べて動脈血の割合が多い。…

※「アランティウス静脈管」について言及している用語解説の一部を掲載しています。

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