Levator Labii Superioris

The levator labii superioris is a facial muscle that raises and everts the upper lip. In Anatomy and Physiology I, it is one of the muscles of facial expression innervated by CN VII.

What is the Levator Labii Superioris?

The levator labii superioris is a muscle of facial expression in Anatomy and Physiology I that lifts the upper lip. It sits just lateral to the nose, with its origin on the maxilla above the infraorbital foramen and its insertion into the skin of the upper lip.

When it contracts, the upper lip moves upward and slightly outward, a motion called eversion. That movement exposes the upper teeth and changes the shape of the mouth, which is why this muscle shows up in expressions tied to disgust, contempt, or a sneer. It is not a chewing muscle, and it does not move the jaw. Its job is purely to change facial expression.

This muscle is part of the facial expression group, so it works with nearby muscles instead of acting alone. The zygomaticus major may pull the corners of the mouth upward, while orbicularis oris shapes the lips themselves. The levator labii superioris adds the specific upper-lip lift that gives a face a more detailed expression than a simple smile or frown.

In lab, you usually identify it by its position and action. If a model or diagram shows a slender muscle running from the upper maxilla to the upper lip, near the side of the nose, that is the levator labii superioris. If you are tracing facial movements, think of the sequence as nerve signal from CN VII, then muscle contraction, then visible upper-lip elevation.

A common mistake is to confuse it with muscles that move the mouth corner or the lower lip. The levator labii superioris affects the upper lip only, so its visible effect is higher on the face than muscles such as zygomaticus major or depressor labii inferioris.

Why the Levator Labii Superioris matters in Anatomy and Physiology I

This muscle matters because it shows how Anatomy and Physiology I connects structure to visible movement. You are not just memorizing a name on a diagram, you are learning how a tiny facial muscle changes expression by pulling on skin rather than bone.

The levator labii superioris also helps you see how facial expression muscles are organized around function. Some muscles lift the lip, some draw the mouth corners sideways, and some tighten or compress the lips. When you compare them, you start to notice that each muscle contributes a small, specific action that becomes a recognizable expression only when combined with other muscles.

It also fits into the bigger rule that all muscles of facial expression are innervated by the facial nerve, CN VII. If your instructor asks about nerve supply, a facial paralysis case, or a Bell's palsy example, this muscle is one of the structures you would expect to be affected.

In practical course work, this term helps you read muscle charts, identify structures on models, and explain how an expression is produced from muscle action. It is a small muscle, but it is a good example of the course theme that anatomy and function are inseparable.

How the Levator Labii Superioris connects across the course

Zygomaticus Major

Zygomaticus major works with the levator labii superioris in facial expression, but it pulls the mouth corner upward and laterally instead of lifting the upper lip. If you compare the two, you can separate a smile-like motion at the corner of the mouth from a more localized upper-lip lift near the nose. That distinction matters on diagrams and muscle ID questions.

Orbicularis Oris

Orbicularis oris surrounds the mouth and changes lip shape by closing, puckering, and compressing the lips. The levator labii superioris does the opposite kind of action at the upper lip, lifting it away from the teeth. These muscles often work together to create complex expressions, so knowing which one moves the lip up and which one shapes the mouth helps you read facial movement more accurately.

Corrugator Supercilii

Corrugator supercilii is another facial expression muscle, but it acts near the eyebrows, not the mouth. Pairing it with levator labii superioris shows how different small muscles create expression in different zones of the face. If a question asks you to identify a muscle from its location, this contrast helps you avoid mixing up the brow region with the upper-lip region.

Depressor Labii Inferioris

Depressor labii inferioris moves the lower lip downward, which makes it a useful comparison for levator labii superioris. One muscle lifts the upper lip, while the other pulls the lower lip down, so the two are easy to confuse if you do not anchor them to the correct lip. This kind of paired comparison is common in muscle identification and labeling.

Is the Levator Labii Superioris on the Anatomy and Physiology I exam?

A quiz image ID or lab practical may ask you to point to the muscle near the side of the nose that lifts the upper lip. You would identify levator labii superioris by location, origin on the maxilla above the infraorbital foramen, and action on the upper lip. If the question gives a facial expression case, you should connect the movement to a facial nerve, CN VII, and to facial expressions such as disgust or contempt. On diagrams, the safe move is to separate it from muscles that move the mouth corner, the brow, or the lower lip. In written responses, use both structure and function: where it is, what it does, and how it contributes to expression.

The Levator Labii Superioris vs Zygomaticus Major

These are often confused because both help with facial expression near the upper cheek area. Levator labii superioris lifts the upper lip, especially beside the nose, while zygomaticus major pulls the corner of the mouth upward and outward. If the movement is centered on the upper lip, think levator labii superioris. If the movement is centered on the smile line or mouth corner, think zygomaticus major.

Key things to remember about the Levator Labii Superioris

• Levator labii superioris is a facial muscle that raises and everts the upper lip.

• Its origin is on the maxilla above the infraorbital foramen, and it inserts into the skin of the upper lip.

• The muscle helps create expressions such as disgust and contempt by changing the shape of the upper lip.

• It works with other facial muscles, but its specific action is upper-lip elevation, not jaw movement or lip closure.

• In Anatomy and Physiology I, you should recognize it by location, action, and its innervation from the facial nerve, CN VII.

Frequently asked questions about the Levator Labii Superioris

What is levator labii superioris in Anatomy and Physiology I?

Levator labii superioris is a facial expression muscle that lifts the upper lip. It runs from the maxilla to the upper lip and is part of the group of muscles controlled by the facial nerve, CN VII. In class, you usually meet it when labeling facial muscles or explaining how expressions are formed.

Where is the levator labii superioris located?

It is located just lateral to the nose and medial to the infraorbital foramen. That placement matters because it helps you distinguish it from nearby facial muscles on a model or diagram. If you can find the side of the nose and upper lip, you are in the right region.

What does levator labii superioris do?

Its main action is elevating and everting the upper lip. That means the lip moves upward and slightly outward, which can expose the upper teeth and change the shape of an expression. The motion is subtle, but it is part of the face's detailed emotional vocabulary.

How is levator labii superioris different from zygomaticus major?

Levator labii superioris lifts the upper lip, while zygomaticus major pulls the corner of the mouth upward and laterally. They can work together during facial expression, but they do not produce the same movement. If the question is about the lip itself, think levator labii superioris. If it is about the mouth corner, think zygomaticus major.