Editing Tears (section)

=== Types ===
There are three basic types of tears: basal, reflex and emotional.<ref name="onlinelibrary.wiley.com" />
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!Category
!Description
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| Basal tears
|In healthy [[mammal]]ian eyes, the [[cornea]] is continually kept wet and nourished by ''basal tears''. They lubricate the eye and help keep it clear of [[dust]]. Tear fluid contains water, [[mucin]], [[lipids]], [[lysozyme]], [[lactoferrin]], [[lipocalin]], [[lacritin]], [[immunoglobulin]]s, [[glucose]], [[urea]], [[sodium]], and [[potassium]]. Some of the substances in lacrimal fluid (such as lysozyme) fight against [[bacteria]]l [[infection]] as a part of the [[immune system]]. Lysozyme does this by dissolving a layer in the outer coating, called peptidoglycan, of certain bacteria. It is a typical body fluid with salt content similar to blood plasma. Usually, in a 24-hour period, 0.75 to 1.1&nbsp;grams (0.03–0.04-ounce avoirdupois) of tears are secreted; this rate slows with age.<ref name="ReferenceA" /> 
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| Reflex tears
|The second type of tears results from irritation of the eye by foreign particles, or from the presence of irritant substances such as [[onion]] vapors, [[perfume]]s and other fragrances, [[tear gas]], or [[pepper spray]] in the eye's environment, including the cornea, conjunctiva, or nasal mucosa, which trigger [[TRP channels]] in the [[ophthalmic nerve]].{{Citation needed|date=December 2019|reason=removed citation to predatory publisher content}} It can also occur with bright light and hot or peppery stimuli to the tongue and mouth. It is also linked with vomiting, coughing, and yawning.<ref name="ReferenceA" /> These ''reflex tears'' attempt to wash out irritants that may have come into contact with the eye.
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|Emotional tears (psychic tears)
|The third category, in general, referred to as ''crying'' or ''weeping'', is increased tearing due to strong [[emotional stress]], pleasure, [[anger]], [[suffering]], [[mourning]], or [[Pain|physical pain]]. This practice is not restricted to negative emotions; many people cry when extremely happy, such as times of intense humor and laughter. In humans, ''emotional tears'' can be accompanied by reddening of the face and sobbing—cough-like, convulsive breathing, sometimes involving spasms of the whole upper body. Tears brought about by emotions have a different chemical makeup than those for lubrication; emotional tears contain more of the protein-based hormones [[prolactin]], [[adrenocorticotropic hormone]], and [[Leu-enkephalin]] (a natural painkiller) than basal or reflex tears. The [[limbic system]] is involved in the production of basic emotional drives, such as anger, fear, etc. The limbic system, or, more specifically the hypothalamus, also has a degree of control over the autonomic system. The [[parasympathetic]] branch of the [[autonomic nervous system]] controls the lacrimal glands via the neurotransmitter [[acetylcholine]] through both the [[nicotinic]] and [[muscarinic]] receptors. When these receptors are activated, the lacrimal gland is stimulated to produce tears.<ref>Skorucak A. [http://www.scienceiq.com/Facts/ScienceOfTears.cfm "The Science of Tears."] ScienceIQ.com. Accessed September 29, 2006.</ref>
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