Morphological Features Of Left And Right Ventricular Muscular Bands In Goat Heart

Background: There are ventricular bands in hearts of kinds of animals, and the forms are various. But there are different forms between different species. Before there were many records about left ventricular bands, no right ventricular bands. Many results of clinical researchers are displayed: The existence of ventricular bands possibly caused cardiac murmur and arrhythmia. As a kind of animal frequently used, ventricular bands of goat were less reported until today. The purpose in experimental process was to investigate the anatomical and histological features and ultra-structures of ventricular bands, and to analyze quantitatively data by optical microscope, transmission electron-microscope (TEM) and computer image analysis, for discovering the morphological basis of how the ventricular bands can trigger ventricular arrhythmia and cardiac murmur.Methods:1.Eighty-six sound healthy adult goats were selected. Their weight range from 25-30kg, anatomic observation of ventricular muscular bands was performed. From 20 goat hearts, 23 left ventricular bands, 17 right ventricular bands and the subendocardial tissue 3mm 3mm of left surface of ventricular septum were obtained, paraffin section for HE and Masson staining and observed by light microscopy.2. Six left ventricular bands and 6 right ventricular bands were selected for observation of ultra-structure by TEM.3. The cytometric examination of Purkinje cells from the ventricular bands and the subendocardial were determined by using HPLAS-2000 computer imagine analysis system. The statistic data were managed by SPSS software.Results:1. The detectable rate of the left ventricular bands were more than that of the right bands . The morphology of more left ventricular bands was various, but that of right ventricular bands was simpler. And the vertical bands were more than the horizontal bands.2. Under light microscope it could be seen that ventricular bands were mostly oblate and few were perfectly round. The axis of the bands was mainly made up of Purkinje cells. There were much difference among the shapes and sizes of Purkinje cells. Compared with Purkinje cells under subendocardium, most were cells with stab or irregular forms besides round or oblate ones. The longer the bands, the more and the longer the stab form cells, and even polynuclear cells could be seen. In the ventricular bands, common cardiac muscle cells could also be seen and the cardiac muscle cells were lined parallel, and their direction was the same as that of the long axis. Collagen fiber tissues around the bands went deep into the bands and separated and covered the Purkinje cells into cells handle of different sizes.3. In ventricular bands Purkinje cells could be seen in groups under TEM, among Purkinje cells typical intercalated disk structure was formed in some parts .The nucleus of Purkinje cell mostly appeared round or long-shaped in vertical section. Muscular fibrin in cytoplasma was rich and regular. Myofilament was clear, in order and parallel. There were rich nerve twig occurred. Direct contact of nerve twig and Purkinje cells forming vesicles and numerous capillary vessels.Conclusion:1. Muscular bands of various size, shape and length existed in the right andleft ventricles, but those in right ventricles were less obviously. And the vertical bands were more than the horizontal bands.2. In the bands existed the similar Purkinje cells to those below subendocardium, the former entrapped and separated by collagen fiber tissues. There are rich special junctures among the cells.3.In ventricular bands there were rich nerve twig occurred. Direct contact of nerve twig and Purkinje cells forming vesicles and numerous capillary vessels.