biology

Nasolabial fold

Nasolabial fold is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Nasolabial fold rather than just read about it. In short: The nasolabial folds, commonly known as "smile lines" or "laugh lines", are facial features. They are the two skin folds that run from each side of the nose to the corners of the mouth.

Key takeaways

Nasolabial fold belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Nasolabial fold to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Nasolabial fold from memory before moving on to harder problems.

Reference excerpt

The nasolabial folds, commonly known as "smile lines" or "laugh lines", are facial features. They are the two skin folds that run from each side of the nose to the corners of the mouth. They are defined by facial structures that support the buccal fat pad. They separate the cheeks from the upper lip. The term derives from Latin nasus for "nose" and labium for "lip". Other people suggest the term melolabial fold, or the lip-cheek fold or groove. It is also known as the nasolabial sulcus.

Cosmetology With ageing the fold may grow in length and depth. Dermal fillings may be used to replace lost fats and collagen in this facial area.

See also Epicanthal fold Nasalis muscle Marionette lines

References

Illustrations

Worked examples

Example 1 — a first encounter with Nasolabial fold

Start with the simplest possible case. Write down what Nasolabial fold claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Nasolabial fold before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Nasolabial fold ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Nasolabial fold

In research: Nasolabial fold appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Nasolabial fold in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Nasolabial fold is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cosmetics, Facial features, Skin anatomy, so understanding it makes those chapters shorter.
In everyday life: Look for Nasolabial fold outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Nasolabial fold in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Nasolabial fold means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Nasolabial fold out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Nasolabial fold in simple terms?

The nasolabial folds, commonly known as "smile lines" or "laugh lines", are facial features. They are the two skin folds that run from each side of the nose to the corners of the mouth.

Why does Nasolabial fold matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Nasolabial fold?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Nasolabial fold.