山羊心脏腔静脉肌袖大体解剖及超微结构研究

Study of Atrial Myocardial Extensions Into Goat Caval Veins in Gross Anotomy and Ultrastructure

目的对山羊心脏上下腔静脉肌袖进行大体观测及电镜观察,为研究上下腔静脉肌袖与局灶性房颤的关系提供形态学基础。方法采用大体解剖方法和电镜观察羊心的上下腔静脉及其表面的心肌纤维。结果羊的上腔静脉心肌袖的出现率是100%,肌袖的长度、宽度、厚度分别为(1.41±1.00)cm、(1.05±0.26)cm、(0.12±0.04)cm;羊的下腔静脉心肌袖的出现率是98%,肌袖的长度、宽度、厚度分别为(1.32±0.32)cm、(1.03±0.28)cm、(0.13±0.06)cm;肌纤维多数来源于右心房前后壁,也有来自于左心房或左右心房的。电镜下可见肌袖细胞之间存在特化连接。细胞核为椭圆形,细胞质内的肌原纤维和线粒体比较丰富。细胞之间存在丰富的神经末梢和毛细血管。心肌袖细胞的特征与心房心肌细胞无明显差异。结论①山羊心脏的上下腔静脉与右心房交界处普遍存在心肌袖组织,成为沟通左右心房的又一重要通道,可能是心电折返的形态学基础;②心肌袖细胞与心房心肌细胞之间无明显差异,提示肌袖与心房肌具有同源性。

Objective： By observing and measuring goat superior and inferior venacardiac muscle sleeve, studying the ultrastructure of vena cardiac muscle sleeveunder the electron microscope, this study aims at providing morphological basefor the study of the relationship between caval vena cardiac muscle sleeve and focal atria fibrillation. Methods The morphology of SVC and IVC and the morphological change of their myocardial fiber on goat hearts was observed and measured under the electron microscope. Results The emerging frequencyof goat superior vena cardiac muscle sleeve is 100% ,the length, width and thickness of myo-sleeve is （1.41 ± 1.00） cm, （1.05 ± 0. 26） cm, （0.12 ± 0.04） cm, respectively; the emerging frequency of goat inferior vena cardiac muscle sleeve is 98 %, the length, width and thickness of myo-sleeve is （ 1.32 ±0.32） cm, （ 1.03 ± 0. 28） cm, （0.13 ± 0.06） cm, respectively. Most muscle fibers came from the right atrium anterior and the posterior wall, and some from the left atrium or both the left and right atrium. Under the electron microscope, there is specialization conjunction among cells of myo-sleeves. Those cell nucleus is of oval-shap, much richer in intracytoplasmic muscle fibril and chondriosome. There are affluent nerve endings and blood capillaries. The cell character of myo-sleeve is not significantly different from that of atrium myocardium. Conclusions （1） There are widespread cardiac muscle sleeve tissues at the junctureof goat superior and inferior caval vein and the right atrium, which has been a passageway to link up left and right atrium and a possible morphological foundation of electrocardioreentry. （2） There is no significant difference between the cell of myo-sleeve and of atrium myocardi- urn. It suggests that myo-sleeveand atrial muscles are homological.