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Related to lachrymation: lacrimation


Normal secretion of tears.
Excessive secretion of tears, as in weeping.



in mammals, including man, the secretion of tears by the lacrimal gland. A continuous process that ceases only during sleep, lacrimation is a reflex that occurs when the cornea becomes irritated or dry. Blinking causes tears to be conducted to the inner canthus, where the lacrimal points and canaliculi, lacrimal sac, and nasolacrimal canal commence.

Man normally secretes 0.5–1 milliliters of tears daily. Lacrimation may intensify (hypersecretion) when an individual experiences such emotions as pain, anger, and joy, and when irritation occurs at the branching of the trigeminal nerve. Lacrimation decreases sharply (hyposecretion) with certain eye diseases, for example, trachomatous xerosis.


Odintsov, V. P. Kursglaznykh boleznei, 5th ed. Moscow, 1946.
Tikhomirov, P. E. Patologiia i terapiia slezootvodiashchikh putei. Leningrad, 1949.
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Nat mur Weakness, photophobia, itchy eyes, lachrymation, swelling of the eyes and migraine headaches that are worse from sunrise to sunset, numbness and tingling of the tongue, sneezing and coryza may be seen here.
Because they are powerful inhibitors of carboxylic ester hydrolases, including acetyl-cholinesterase (AChE; found in nerve tissues and erythrocytes) and butyrylcholinesterase (plasma or pseudocholinesterase), individuals exposed to high levels of OPs can develop acute cholinergic syndrome, which is characterized by a variety of symptoms including rhinorrhea, salivation, lachrymation, tachycardia, headache, convulsions, and death (Karalliedde et al.