関連ワード:  what is circulatory system in humans    what is vascular system in humans    what is double circulatory system in humans    what is blood circulatory system in humans    what is circulatory system in man    what is circulatory system in body    what is vascular system in body    what is the role of circulatory system in humans    what is the function of circulatory system in humans    what is the circulatory system in man can be compared with