Lip: Soft, movable tissue forming the visible opening of the mouth in humans and many animals.

Lips are horizontal pairs of soft tissue attached to the jaws. They facilitate eating, speech articulation, and tactile sensation through dense nerve endings.

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Lips lack sweat glands and hair follicles.
Infraorbital and mental nerves provide sensation.
Vermilion border marks the edge of colored tissue.
Muscles enable speech and facial expressions.
Thin skin reveals underlying blood vessels.

What it is

Lips form the horizontal opening of the mouth in humans and other mammals. They consist of an upper part called the labium superius oris and a lower part known as the labium inferius oris. The boundary where lip tissue meets facial skin is the vermilion border, containing the distinctive red vermilion zone. This area lacks hair and sweat glands, making it thinner than surrounding skin. Nerve endings make lips highly sensitive to touch, temperature, and texture.

History and origin

Mammalian lips evolved from simple tissue folds into prominent, muscular structures. This development allowed for complex food handling, such as suckling and gulping. In humans, they also became essential for articulating sounds. Unlike birds or turtles that have hard beaks, mammal lips remain soft and mobile, connected directly to jaw muscles for precise control during feeding and communication.

What it means

Lips serve as primary tools for social interaction and expression. They convey emotions through smiles, frowns, and pouts. In human attraction, full lips are often perceived as indicators of health and youthfulness due to hormonal influences. Culturally, they symbolize sensuality and intimacy. Their sensitivity makes them central to kissing and non-verbal communication across various societies.

The science

Lip skin contains fewer melanocytes than face skin, allowing blood vessels to show through, creating a red appearance. The infraorbital and mental nerves supply sensation. Muscles derived from the second pharyngeal arch, innervated by the facial nerve, control movement. The thin epithelium lacks protective oils, leading to rapid drying. Cyanosis can cause blue discoloration due to low oxygen levels in the blood.

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Styling and care

No grooming is required beyond maintaining hydration to prevent chapping. Natural variations in size and shape occur across populations. Cosmetic products like lipstick may enhance color perception. Piercings or surgical augmentation exist but are optional personal choices. Natural lip function relies on muscle coordination for speech and eating without external aids.

In culture

Lips appear frequently in art and media as symbols of beauty and emotion. Literary references often highlight their role in speech and kiss. Psychological studies explore their link to perceived attractiveness. Medical conditions like cleft lip or cheilitis are documented in clinical literature. Cultural veiling practices sometimes associate lips with modesty or sexuality.

Questions people ask about Lip

Why do lips look red?

Lip skin has fewer melanocytes than surrounding face skin. This allows underlying blood vessels to show through clearly. The result is a reddish appearance known as the vermilion zone. Darker skin tones may show less redness due to higher melanin content.

What nerves control lip sensation?

The infraorbital nerve supplies the upper lip and surrounding face. The mental nerve provides sensation to the lower lip and gums. These branches of the trigeminal nerve allow lips to detect touch, temperature, and pain effectively.

How do lips help with speech?

Lips create consonant sounds like 'b', 'p', and 'm' by closing or rounding. They also shape vowels through rounding movements. This articulation is crucial for clear verbal communication and understanding spoken language visually.

Why do lips get dry easily?

Lip skin lacks sweat glands and oil-producing structures. Without these natural moisturizers, moisture evaporates quickly. Exposure to wind or cold accelerates drying, leading to chapping if not managed with external hydration.

Good reading and sources

BBC NEWS | HealthBBC, Article

Where this page comes from

The facts on this page come from the Wikipedia article "Lip", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). EveryFaceShape rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.

It may contain mistakes, and figures change over time. Nothing here is investment or buying advice. If something is wrong, tell us. Last refreshed 2026-11-15.

Lip