Bartelings M M, Gittenberger-de Groot A C
Department of Anatomy and Embryology, University of Leiden, The Netherlands.
Int J Cardiol. 1989 Mar;22(3):289-300. doi: 10.1016/0167-5273(89)90270-2.
The separation process of the heart by which two great arteries and two outflow tracts are formed, was studied microscopically in 20 human embryos, ranging from 6 to 28 mm crown-rump length and macroscopically in eight hearts, ranging from 28 weeks of gestation to 80 years of age. The proximal (primary fold) and distal (ventriculo-arterial junction) borderlines of the outlet segment of the embryonic heart are important landmarks in this process. The remarkable, curved and twisted configuration of the ventriculo-arterial junction implies that the position of the arterial orifices, as well as the relative dimensions of the corresponding outflow tracts, are, already in a very early stage, similar to those in the fully developed heart. It furthermore implies that the separation by the aorto-pulmonary septum starts at this level and immediately involves the outlet segment where the two columns of the aorto-pulmonary septum mobilize the myocardium to form the posterior wall of the right ventricular outflow tract, rather than a septum between both outflow tracts. These findings make the morphology of the outflow tract of the normal heart comprehensible from a developmental point of view and throw a new light upon the morphogenesis of outflow tract malformations.
通过对20例人胚胎进行显微镜观察，研究了心脏形成两条大动脉和两个流出道的分离过程，这些胚胎的冠臀长为6至28毫米；还对8个心脏进行了宏观观察，这些心脏来自妊娠28周的胎儿至80岁的成年人。胚胎心脏流出段的近端（初级褶皱）和远端（心室 - 动脉交界处）边界线是这一过程中的重要标志。心室 - 动脉交界处显著的弯曲和扭曲形态表明，动脉口的位置以及相应流出道的相对尺寸在很早阶段就已与完全发育的心脏相似。这还意味着主动脉 - 肺动脉隔的分离始于这个层面，并立即涉及流出段，在该部位，主动脉 - 肺动脉隔的两柱带动心肌形成右心室流出道的后壁，而不是在两个流出道之间形成隔膜。这些发现从发育角度解释了正常心脏流出道的形态，并为流出道畸形的形态发生提供了新的线索。
