noun
Medical term referring to the heart and blood vessels. Synonymous with 循環系 (じゅんかんけい).
See also: 循環系
循環器系の病気は生活習慣と深く関係している。
Diseases of the circulatory system are closely related to lifestyle habits.
Synonym; 循環器系 is slightly more common in medical contexts, while 循環系 is a broader term that can also refer to non-biological circulation systems.
Compound of 循環器 (じゅんかんき, 'circulatory organ') + 系 (けい, 'system').