Lips are the body parts seen in the mouths of humans and many animals.
The lips are soft, moveable, and serve as an opening for food intake and in the articulation of sounds and speech. Human lips are sense organs of touch, and can be a sensitive zone when used in kisses and other intimacy acts.
Video Lip
Structure
The upper and lower lips are called "labium superius oris" and "Labium inferius oris", respectively. The point at which the lips meet the skin around the mouth area is the vermilion border, and the usually reddish area within the border is called the vermilion zone. The border of the upper lip vermilion is known as the cupid arc. The fleshy projection located in the center of the upper lip is a tubercle known by various terms including procheilon (also spelled prochilon), "superioris labii tuberculum", and "labial tuberculum". The vertical groove extending from the procheilon to the nasal septum is called philtrum.
The lip skin, with three to five layers of cellular, is very thin compared to typical facial skin, which has up to 16 layers. With light skin tone, the lip skin contains fewer melanocytes (cells that produce melanin pigment, which gives the skin a color). Therefore, blood vessels appear through the skin of the lips, leading to the famous red dye. With darker skin tones this effect is less prominent, because in this case the lip skin contains more melanin and thus is visually darker. The skin of the lips forms the boundary between the outer skin of the face, and the mucous membrane of the inside of the mouth.
Skin lips are hairless and do not have sweat glands. Therefore, it lacks a layer of protection of sweat and body oil that keeps the skin smooth, inhibits pathogens, and regulates warmth. For this reason, the lips dry out faster and more easily broken.
The lower lip is formed from the superiority of the mandible, the branch of the first pharyngeal arch. The lower lip covers the anterior body of the mandible. This is decreased by the inferioris liver muscle depressor and orbicularis oris limiting it inferiorly.
The upper lip covers the anterior surface of the upper jaw body. The upper half is plain-skinned and has depression at its center, just below the nasal septum, called philtrum, which is Latin for the lower nose, while the bottom is a very different red color, more similar to the inner color of the mouth, and the term vermillion refers to the colored part of the upper or lower lip.
It is raised by the superiorist labi levator and connected to the lower lip by a thin layer of the lips itself, which can be seen by opening the mouth wide in front of the mirror.
Depletion of upper lip vermilion and philtrum smoothing are two characteristics of fetal alcohol syndrome, lifelong defects caused by alcohol consumption during pregnancy.
Microanatomy
Lip skin is a stratified squamous epithelium. The mucous membrane is represented by a large area of ​​the sensory cortex, and is therefore very sensitive. The Frenulum Labii Inferioris is the lower lip frenulum. The Frenulum Labii Superioris is the upper lip frenulum.
Supply of nerves
- Trigeminal nerves
- The infraorbital nerve is the branch of the maxillary branch. It not only supplies the upper lip, but many of the facial skin between the upper lip and the lower eyelid, except for the bridge of the nose.
- The mental nerves are branches of the mandible branch (via the inferior alveolar nerve). It supplies the skin and mucous membranes of the lower lip and labial gingiva (gums) anteriorly.
Blood supply
The facial artery is one of the six non-terminal branches of the external carotid artery.
This artery supplies both lips by the superior and inferior labial branches. Each of the two branches bifurcation and anastomose with their counterpart from another terminal.
Muscle
The muscles that work on the lips are considered part of the muscles of facial expression. All facial expression muscles are derived from the mesoderm of the second pharyngeal arch, and are therefore given (motor supply) by the nerve of the second pharyngeal arch, the facial nerve (the 7th cranial nerve). The muscles of facial expression are special members of panniculus carnosus, which attaches to the dermis and so wrinkles, or attenuates the skin above it. Functionally, the muscles of facial expressions are arranged in groups around the orbit, nose and mouth.
The muscles that work on the lips:
- Buccinator
- Orbicularis oris (muscle complex, previously thought to be a sphincter or a single muscle ring)
- The anchor point for some muscles
- Modiolus
- Lip enhancement
- Levator labii superioris
- levator labii superioris alaeque nasi
- Levator anguli oris
- Zygomaticus minor
- Zygomaticus major
- Depressed lips
- Risorius
- Depressor anguli oris
- Depressor labii inferioris
- Mentalis
Maps Lip
Function
Food intake
Because they have their own muscles and limit the muscles, the lips move easily. Lips are used for eating functions, such as holding food or putting it in the mouth. In addition, the lips function to close the closed air tight mouth, to hold food and drink inside, and to prevent unwanted objects. Through making a narrow funnel with lips, the mouth suction increases. Suction is very important for breastfeeding babies. Lips can also be used to suck other contexts, such as sucking straws to drink fluids.
Articulation
Lips serve to create different sounds - especially the sound of labial, bilabial, and labiodental consonants as well as rounding vocals - and thus an important part of speech equipment. Lips allow whistling and performing wind instruments such as trumpets, clarinets, flutes, and saxophones. People who experience hearing loss may unconsciously or consciously read lips to understand the conversation without needing to see the actual sound.
tactile organ
Lips have many nerve endings and react as part of touch (touch) senses. Lips are very sensitive to touch, warmth, and cold. It is therefore an essential aid to explore unknown objects for infants and toddlers.
Erogenous Zone
Because of the high number of nerve endings, the lips are sexually sensitive zones. Therefore the lips play an important role in kisses and other intimacy acts.
The lips of a woman are also a real expression of her fertility. In research conducted on the science of human attractiveness, psychologists have concluded that the sexual and sexual attractiveness of a woman is closely related to her hormonal makeup during puberty and development. Contrary to the effects of testosterone on male facial structures, the effects of female estrogen levels function to maintain relatively young and "young boyish" facial structures at puberty and during late maturation. It has been shown that the more estrogen a woman possesses, the more her eyes and lips are getting fuller, the characteristics are considered more feminine. Surveys conducted by sexual psychologists also found that universally, men found lips full of women to be more sexually attractive than less lips. Therefore, a woman's lips are sexually attractive to men because they serve as a biological indicator of women's health and fertility. A woman's lipstick (or increased lip gloss) tries to capitalize on this fact by creating the illusion that a woman has more estrogen than she really is, and thus she is more fertile and attractive.
The size of the lips is associated with sexual attraction in both men and women. Women are attracted to men with masculine lips, which are more medium-sized and not too big or too small; they must be rude and sensual. In general, the researchers found that small nose, big eyes and lips excite sexually attractive both in men and women. Lips may swell temporarily during sexual arousal due to swelling with blood.
Facial expressions
Lips contribute greatly to facial expressions. Lips are seen expressing emotions such as smiles or scowls, iconically by the arches of the lips forming open or open-ended parabola, respectively. Lips can also be made sullen when whining, or eager to be provocative.
Clinical interests
As a body organ, the lips can be the focus of the disease or show symptoms of the disease:
- One of the most frequent lips changes is blue due to cyanosis; blood contains less oxygen, and thus has a dark red to blue color, which is visible through a thin skin. Cyanosis is the reason why corpses sometimes have blue lips. In cold weather cyanosis can appear, especially in winter, blue lips may not be an unusual sight.
- Inflammation of the lips is called cheilitis. It can be in several forms such as chapped lips (dry, lips peeling), angular cheilitis (inflammation of the corners of the mouth), herpes labialis (cold sore, herpes simplex form) and actinic cheilitis (chronic sun damaged lips).
- Cleft lip is a type of birth defect that can be successfully treated with surgery.
- Carcinomas (malignant cancers arising from epithelial cells) on the lips, mostly caused by tobacco use and excessive sun exposure. Alcohol seems to increase the risk of carcinoma associated with tobacco use. The most common are diffuse and often hyperkeratinised lesions, sometimes having nodular forms and growing infiltratively, and can also be a combination of two types. More common in the lower lip, where it is also much more defamatory. Lower lip carcinoma is exclusively a planocellular carcinoma, whereas in the upper lip, it can also be basocellular carcinoma.
Society and culture
Lips are often seen as symbols of sensuality and sexuality. It has many origins; especially, the lips are sensitive and sensitive organs that are very sensitive. Furthermore, in many cultures of the world, the mouths and lips of women are closed because of their association of representation with the vulva, and because of their role as a female secondary sexual organ.
As part of the mouth, the lips are also associated with the symbolism associated with the mouth as the orifice where food is taken. Lips are also associated symbolically with neonatal psychology (see eg the oral stage of psychology according to Sigmund Freud).
Lip piercing or lip enlargement is sometimes done for beauty reasons. Products designed for use on lips include lipstick, lip gloss and lip balm.
Other animals
In most vertebrates, the lips are relatively unnecessary tissue folds located outside the jaw. However, in mammals, they become much more prominent, separated from the jaw by a deep cleft. They are also more mobile in mammals than in other groups, because only in this group they have inherent muscles. In some teleost fish, lips can be modified to carry sensitive barbels. In birds and turtles, their lips are hard and keratin, forming a strong beak. Clevosaurids such as Clevosaurus are noted for the presence of bone "lips"; in this species the jaw-like general projection tooth for all sphenodontians forms the edge like a beak around the jaw, protecting the inner teeth.
See also
- Upper stiff lips
References
Further reading
- Tomiyama N, Ichida T, Yamaguchi K; Ichida; Yamaguchi (2004). "The activity of lower lip muscle electromyography while chewing with lips in contact and separated" (abstract) . Angle Orthod . 74 (1): 31-6. doi: 10.1043/0003-3219 (2004) 074 & lt; 0031: EAOLLM & gt; 2.0.CO; 2 (off 2017-01-16). PMIDÃ, 15038488 CS1 maint: Multiple names: list of authors (links)
- Bisson M, Grobbelaar A; Grobbelaar (2004). "The aesthetic properties of the lips: model and nonmodel comparison" (abstract) . Angle Orthod . 74 (2): 162-6. doi: 10.1043/0003-3219 (2004) 074 & lt; 0162: TEPOLA & gt; 2.0.CO; 2 (off 2017-01-16). PMIDÃ, 15132441
- McMinn, R. M. H.; Finally, R. J. (1994). Last, regional and applied anatomy . Edinburgh: Churchill Livingstone. ISBNÃ, 0-443-04662-X Ã,
External links
- ent/7 in eMedicine
- hednk-030 - Embryo pictures at the University of North Carolina
- Anatomy at oralhealth.dent.umich.edu
Source of the article : Wikipedia
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