Customer Support. Busey Holidays Observed New Year's Eve all facilities close at 5 p.m. New Year's Day all facilities closed Martin Luther King Day customer support available 8 a.m. - 1 p.m. CST Presidents' Day customer support available 8 a.m. - 1 p.m.
Orbicularis oris muscle. In human anatomy, the orbicularis oris muscle is a complex of muscles in the lips that encircles the mouth. Until recently, it was misinterpreted as a sphincter, or circular muscle, but it is actually composed of four independent quadrants that interlace and give only an appearance of circularity.
The reason can be found in the structure of the lips themselves. The lips' structure is actually different than other skin. As shown in the diagram to the left, lips do not have the same protective outer layer, or stratum corneum, found in other skin; nor do lips have the same amount of oil and sweat glands. Sweat glands add moisture to skin, but the lips' only source of moisture is saliva inside the mouth. Thus, harsh winter wind, cold, sun and dryness--indoors and outdoors--make lips more susceptible to dryness and a vulnerable target for chapping.