tear duct and gland
Structures that produce, distribute, and carry away tears. An almond-shaped gland above the outer corner of each eye secretes tears between the upper eyelid and the eyeball. Tears moisten and lubricate the conjunctiva (the membrane that lines the eyelid and covers the white of the eye) and then flow into the barely visible openings (near the inner corners of the eyelids) of the tear ducts, which lead to the nasal cavity. Oil (from sebaceous glands on the edge of the eyelid) keeps tears from spilling out unless secretion increases because of crying or a reflex triggered by stimuli such as eye irritation, bright lights, or spicy foods.
Variants of TEAR DUCT AND GLAND
tear duct and gland or lachrymal duct and gland
This entry comes from Encyclopædia Britannica Concise.
For the full entry on tear duct and gland, visit Britannica.com.
Seen & Heard
What made you look up tear duct and gland? Please tell us what you were reading, watching or discussing that led you here.