http://zh.wikipedia.org/wiki/%E8%84%BE%E8%84%8F
有學者認為中醫理論的「脾」其實對應的是現代醫學的胰臟
and
http://en.wikipedia.org/wiki/Spleen
In China, the spleen '脾 (pí)' counts as the seat of one's temperament and is thought to influence the individual's willpower. Analogous to "venting one's spleen", "發脾氣" is used as an expression for getting angry, although in the view of Traditional Chinese Medicine, the view of "脾" does NOT correspond to the anatomical "spleen".