The coefficient of the lung, thymus and thyroid were significant difference between the young and the middle age group, especially the difference of thymus coefficient was very significant.

• 中年组雌性和雄性的肺、胸腺和甲状腺与青年雌性和雄性的对应脏器系数有差异,其中胸腺脏器系数差异极显著。