The lacrimal apparatus consists of the lacrimal gland, conjunctival sac, lacrimal puncta and canaliculi, lacrimal sac, and nasolacrimal duct. The lacrimal gland secretes tears which drain through the puncta and canaliculi into the lacrimal sac and then nasolacrimal duct into the nose. Obstruction of this drainage system can cause epiphora or excessive tearing. The nose has functions of respiration, olfaction, air conditioning, and protection and is formed externally by skin, cartilage, and bone and internally by three nasal cavities with vestibules, respiratory and olfactory regions.