中文摘要：

背景：对动物胚胎的活体标记试验表明鸡和小鼠胚胎心脏流出道及右心室来自心管外的咽部中胚层。人胚是否有相似情况作者经文献检索尚未见报道。 目的：观察并验证人胚心脏动脉端心肌的来源。 设计、时间及地点：单一样本观察，于2005-10/2006-10在山西医科大学组织胚胎学教研室完成。 材料：山西医科大学各附属医院药物流产后绒毛膜保存完好的早期人胚标本25例。 方法：体视显微镜下仔细分离出胚体。用Carnegie分期法对胚胎进行发育分期，其中C10期、c11期、C12期、C13期、C15期和C16期胚胎各3例，C14期胚胎7例。主要观察指标：应用免疫组织化学PAP法观察了α-平滑肌肌动蛋白和α-横纹肌肌节肌动蛋白在C10晚期至C16期人胚心脏及咽部中胚层的表达型，并用苏木精-伊红染色观察各期心脏及咽中胚层的形态学特征。 结果：C10晚期至C12，流出道远端的脏层心包和心包腔的背侧壁为复层上皮，向壁层心包内延伸逐渐变为单层扁平上皮。背侧心包于C13至C15变为单层上皮。C10晚期至C13流出道远端α-平滑肌肌动蛋白和α-横纹肌肌节肌动蛋白表达可延伸至脏层心包及咽部间充质细胞。C14至C15，流出道逐渐延长，其远端的脏层心包细胞增生并迁至流出道，在近流出道心肌细胞处表达α-平滑肌肌动蛋白和α-横纹肌肌节肌动蛋白。 结论：C10至C15，咽中胚层不断分化出心肌细胞添加至心脏的动脉端使流出道延长，为人胚的前心区；流出道远端心肌可诱导前心区细胞增殖分化为心肌细胞。人胚心脏动脉端心肌来自前心区。

英文摘要：

BACKGROUND： Labeling in chick and mouse embryo in vivo suggested right ventricle and outflow tract of the heart derived from pharyngeal mesoderm distal to the heart tube. It was unclear whether it was the same in human embryo. OBJECTIVE： To explore the origin of cardiomyocytes at the arterial pole of the human embryonic heart. DESIGN, TIME AND SETTING： A single sample experiment was performed at the Department of Histology and Embryology, Shanxi Medical University from October 2005 to October 2006. MATERIALS： A total of 25 cases of early human embryo samples with complete choriou after drug abortion at the Hospital Affiliated to Shanxi Medical University. METHODS： Embryonic plants were isolated under a stereomicroscope. According to Carnegie staging method, embryos were assigned to Carnegie stage 10 （C 10）, C11, C12, C13, C15 and C16 stages （3 cases each） and C14 stages （7 cases）. MAIN OUTCOME MEASURES： Immunohistoehemistry PAP was used to observe the expression patterns of α -smooth muscle actin and α -sarcomeric actin in the human embryonic heart and pharyngeal mesoderm from C10 to C16. Haematoxylin and eosin （HE） staining was employed to observe morphologic characteristics of heart and pharyngeal mesoderm at each stages. RESULTS： From C10 to C12, splanchnic pericardium distal to the outflow tract and dorsal pericardium were stratified epithelium, when extending into parietal mesoderm pericardium gradually transformed into simple squamous epithelium. During the following three stages, dorsal pericardium gradually changed into simple epithelium. During C10 to C13, expression of α -smooth muscle actin and α -sarcomeric actin reached splanchnic pericardium and pharyngeal mesenchymal ceils distal to the outflow tract. From C14 to C15, the outflow tract gradually elongated. Over these stages, splanchnic pericardial cells distal to the outflow tract proliferated and progressively migrated into the outflow tract, expressing α-smooth muscle actin and α-sarcomeric actin wh