Studies on the inferior phrenic vein of rats: the probability of its being a collateral route of blood from the lower portion of the body to the heart.
The principal aim of this study was to elucidate key features of the inferior phrenic vein (IPV) of adult rats to determine whether the IPV has the potential to function as a collateral return route conveying blood from the lower portion of the body to the heart, bypassing the subhepatic vein segment of the inferior caval vein. In rats, the IPVs on both sides were found to reveal a symmetric appearance. They were both composite vessels, being made up of two fellow subvessels, the sternocostal and the lumbocostal veins, which in turn anastomosed in tandem in their periphery with each other, formed a collateral route bridging the interval between the suprarenal and the hepatic vein segments of the inferior caval vein. In rat embryos of E17.5, the sternocostal and lumbocostal veins of the IPV were observed to have been well developed, forming tandem anastomoses more clearly than in adults, thus connecting the subcardinal vein to the hepatic vein segment of the inferior caval vein. This fact substantiates our supposition that the rat's IPV originally has the potential to act as a collateral returning route which allows blood to bypass the subhepatic vein segment of the inferior caval vein.
School of Nursing, Fukui Prefectural College, Japan.
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Mizukami
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Tanaka
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Moriya
D000818:Animals; D003097:Collateral Circulation; D005260:Female; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014680:Veins / Q000033:anatomy & histology; D014682:Vena Cava, Inferior / Q000502:physiology; D014781:Viscera / Q000098:blood supply*