點解人傷心會流眼淚既???

呢個係一個關於心理學既問題
其他動物一樣有淚腺, 用作保濕同消毒, 但係佢地唔會因為唔開心而喊WO!
所以因傷心而喊都可以話係我地人類獨有既行為
至於點解我地傷心時喊呢? 仲未有人可以明確地比到答案!
有待心理學家再繼續做研究lu!

Tears released from the lacrimal glands in the upper eyelid moisten the conjunctiva and keep the eye clean.
Emotion would produce some hormone that stimulate the lacrimal glands to release tears in order to show emotion and relieve stress and anxiety.