Unsourced material may be challenged and fuller dental anatomy pdf. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. The upper and lower lips are referred to as the “Labium superius oris” and “Labium inferius oris”, respectively.
The skin of the lip, with three to five cellular layers, is very thin compared to typical face skin, which has up to 16 layers. With darker skin color this effect is less prominent, as in this case the skin of the lips contains more melanin and thus is visually darker. Therefore, it does not have the usual protection layer of sweat and body oils which keep the skin smooth, inhibit pathogens, and regulate warmth. It supplies not only the upper lip, but much of the skin of the face between the upper lip and the lower eyelid, except for the bridge of the nose. This artery supplies both lips by its superior and inferior labial branches.
Because they have their own muscles and bordering muscles, the lips are easily movable. Lips are used for eating functions, like holding food or to get it in the mouth. In addition, lips serve to close the mouth airtight shut, to hold food and drink inside, and to keep out unwanted objects. Lips can also be used to suck in other contexts, such as sucking on a straw to drink liquids. Lips are very sensitive to touch, warmth, and cold. It is therefore an important aid for exploring unknown objects for babies and toddlers.
A woman’s lips are also a visible expression of her fertility. In studies performed on the science of human attraction, psychologists have concluded that a woman’s facial and sexual attractiveness is closely linked to the makeup of her hormones during puberty and development. It has been shown that the more oestrogen a woman has, the larger her eyes and the fuller her lips, characteristics which are perceived as more feminine. A woman’s lips are therefore sexually attractive to males because they serve as a biological indicator of a woman’s health and fertility.