以下は「Wikipedia」の解説文となる。
Meibomian glands (also called tarsal glands, palpebral glands, and tarsoconjunctival glands) are sebaceous glands along the rims of the eyelid inside the tarsal plate. They produce meibum, an oily substance that prevents evaporation of the eye's tear film. Meibum prevents tears from spilling onto the cheek, traps them between the oiled edge and the eyeball, and makes the closed lids airtight. There are about 25 such glands on the upper eyelid, and 20 on the lower eyelid.
Dysfunctional meibomian glands is believed to be the most often cause of dry eyes. They are also the cause of posterior blepharitis.
【 語 句 】
・sebaceous gland：皮脂腺 ・eyelid：眼瞼 ・tarsal plate：瞼板 ・meibum：マイバム（マイボーム腺分泌物の総称)） ・evaporation：蒸発 ・tear film：涙膜 ・dysfunctional：機能障害性の ・blepharitis：眼瞼炎
【History】
The glands were mentioned by Galen in 200 AD and were described in more detail by Heinrich Meibom (1638–1700), a German physician, in his work De Vasis Palpebrarum Novis Epistola in 1666. This work included a drawing with the basic characteristics of the glands.
【Anatomy 】
Although the upper lid have greater number and volume of meibomian glands than the lower lid, there is no consensus whether it contributes more to the tearfilm stability. The glands do not have direct contact with eyelash follicles. The process of blinking releases meibum into the lid margin.
【 語 句 】
・consensus：一致、総意 ・eyelash：まつ毛 ・follicle：濾胞 ・lid margin：眼瞼縁
【Function】
【Meibum】
〈Lipids〉
Lipids are the major components of meibum (also known as "meibomian gland secretions"). The term "meibum" was originally introduced by Nicolaides et al. in 1981.
The biochemical composition of meibum is extremely complex and very different from that of sebum. Lipids are universally recognized as major components of human and animal meibum. An update was published in 2009 on the composition of human meibum and on the structures of various positively identified meibomian lipids
Currently, the most sensitive and informative approach to lipidomic analysis of meibum is mass spectrometry, either with direct infusion or in combination with liquid chromatography.
The lipids are the main component of the lipid layer of the tear film, preventing rapid evaporation and it is believed they lower the surface tension which helps to stabilize the tear film.
〈Proteins〉
In humans, more than 90 different proteins have been identified in meibomian gland secretions.
【 語 句 】
・lipid：脂質 ・secretion：分泌物 ・sebum：皮脂 ・mass spectrometry：質量分析法 ・infusion：注入 ・liquid chromatography：液体クロマトグラフィー
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