Why Do People's Noses Run When They Cry?

There is a lachrymal gland at the upper comer of the eye, and inside the comer of each eye there is a lachrymal dud connecting the eye and nose. When a person cries, his or her lachrymal gland produces a lot of tears. Some of the tears run down from the comer of the eye and the others go into the nasal cavity through the lachrymal duds. When the mucous membrane is stimulated by the tears, a lot of mucus is secreted. The mucus and tears run out of the nose. That is why people have running noses when they cry.