|Budget Amount *help
¥2,300,000 (Direct Cost : ¥2,300,000)
Fiscal Year 1996 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1995 : ¥1,900,000 (Direct Cost : ¥1,900,000)
1) Development of the vagal cardiac branches (VCB) in chick embryos By tracing the growth of the VCB at earlier stages of chick embryos, we found that the VCB are divided into 2 groups, those destined for the arterial site and those for venous site of the heart. Most important findings in this study that these VCB reveals a simple symmetrical, but not a complex, arrangement in contrast to the description in the leading anatomical as well as the embryological textbooks. Especially, the VCB destined for the venous site were found to follow the developing the superior vena cava and the pulmonary veins, reaching the sinuatrial node and the interatrial septum, the site of location of the atrioventricular node.
2) Unfortunately, the terminology of the VCB of humans and of vertebrates are greatly confused. Every author has applied the same terms to different branches arising from the vagal nerve. For clearing this confusion, we have performed macroscopical studies on the VCB in the chicken, rats, house shrews, and in human adults, and elucidated the morphological features of these branches in a more exact and detailed than ever manner. The results obtained in this study provide us with suff icient evidence to support a confident statement that the fundamental features of the VCB in humans are the same as those in vertebrates, including chicken.