Clinical anatomy : head and neck Why tears in the eye completely stop when the palpebral portion of the lacrimal gland is surgically removed ?

 Why tears in the eye completely stop when the palpebral portion of the lacrimal gland is surgically removed ? 

The smaller palpebral and larger orbital portions make up the lacrimal gland. The lateral border of the levator palpebrae superioris is where the orbital and palpebral segments meet. Ten to twelve ducts (six from the orbital part and eight from the palpebral part) drain the secretions from these areas.
Since the orbital part's ducts also flow through the palpebral part, the orbital part's secretions cannot drain into the conjunctival sac if the palpebral part is surgically removed. Consequently, the removal of the palpebral portion occurs when there are no tears left in the eye.