Our lips are very important in many ways:
- Visual look of face
- Food intake, drool prevention
- Speech articulation
- Playing musical instruments
- Tactile sensory organ
Read my lips--meaning "pay close attention to my words" (link)
Lip service--meaning "minimal compliance only" (link)
Hot Lips -- usually a nick name ; Major Margaret J. "Hot Lips" Houlihan (MASH); Oran Thaddeus Page (jazz trumpeter known as Hot Lips Page by the public and Lips Page by his fellow musicians).
Fat Lip--(idiom) A swelling on the lip
Don't give me any lip --meaning "insolent talk" (link)
My lips are sealed --meaning "one will reveal nothing, especially about a secret" (link)
The Upper (Labium superioris) extends from the base of the nose superiorly, to the nasolabial folds laterally, and to the free edge of the vermilion border inferiorly.
The upper lip is innervated by the terminal branch of the maxillary nerve. It supplies sensation to the lateral nasal sidewall, ala, columella, medial cheek, and upper lip.
The perioral musculature (link shows muscles and discusses phonetics) can be classified into 3 groups based on insertion.
- Group I -- insert into the modiolus (a tendinous thickening at each commissure that serves as an attachment site for several of the upper and lower lip muscles)
- Orbicularis oris --forms a sphincter around the mouth. This muscle purses the lips and presses them against the teeth upon contraction.
- Buccinator --functions to press the lips and cheek against the teeth
- Levator anguli oris -- acts to superiorly elevate the commissure
- Depressor anguli oris -- functions to depress and laterally move the commissure
- Zygomaticus major -- elevates and laterally moves the commissure
- Risorius -- draws the commissure laterally and produces the sardonic smile (Warren Oates, 1928-1982)
- Group II -- insert into the upper lip
- Levator labii superioris -- elevates the upper lip
- Levator labii superioris alaeque nasi -- dilates the nostril and elevates the upper lip
- Zygomaticus minor -- elevates and pulls the commissure laterally. Its contraction contributes to the nasolabial fold.
- Group III -- insert into the lower lip
- Depressor labii inferioris -- depress the lower lip and pulls it slightly laterally (outward)
- Mentalis is a paired central muscle of the lower lip. Since its muscle fibers pass in an inferior direction, the action of the mentalis upon contraction is to elevate the lower lip. The insertion site of the mentalis fibers into the dermis can be observed in the pout expression.
- Platysma is a lip depressor.
Lips and Perioral Region Anatomy; Babak Jahn-Oarwar MD, Keith Blackwell MD; eMedicine Article, October 9, 2007
Visualization of Talking Human Head; Martin Simunek; Department of Computer Science and Engineering, Czech Technical University, Prague / Czech Republic