science

Nasal septum

Nasal septum is a science 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 Nasal septum rather than just read about it. In short: The nasal septum (Latin: septum nasi) separates the left and right airways of the nasal cavity, dividing the two nostrils. It is depressed by the depressor septi nasi muscle.

Key takeaways

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

Reference excerpt

The nasal septum (Latin: septum nasi) separates the left and right airways of the nasal cavity, dividing the two nostrils. It is depressed by the depressor septi nasi muscle.

Structure The fleshy external end of the nasal septum is called the columella or columella nasi, and is made up of cartilage and soft tissue. The nasal septum contains bone and hyaline cartilage. It is normally about 2 mm thick. The nasal septum is composed of four structures:

Maxillary bone (the crest) Perpendicular plate of ethmoid bone Septal nasal cartilage (i.e., quandrangular cartilage) Vomer bone The lowest part of the septum is a narrow strip of bone that projects from the maxilla and the palatine bones, and is the length of the septum. This strip of bone is called the maxillary crest; it articulates in front with the septal nasal cartilage, and at the back with the vomer. The maxillary crest is described in the anatomy of the nasal septum as having a maxillary component and a palatine component.

Development

At an early period, the septum of the nose consists of a plate of cartilage, known as the ethmovomerine cartilage. The posterosuperior part of this cartilage is ossified to form the perpendicular plate of the ethmoid; its anteroinferior portion persists as the septal cartilage, while the vomer is ossified in the membrane covering its posteroinferior part. Two ossification centers, one on either side of the middle line, appear about the eighth week of fetal development in this part of the membrane, and hence the vomer consists primarily of two lamellae. About the third month, these unite below, and thus a deep groove is formed in which the cartilage is lodged. As growth proceeds, the union of the lamellae extends upward and forward, and at the same time, the intervening plate of cartilage undergoes absorption. By the onset of puberty the lamellae are almost completely united to form a median plate, but evidence of the bilaminar origin of the bone is seen in the everted alae of its upper border and in the groove on its anterior margin.

Clinical significance The nasal septum is the wall between the left and right sides of the nose. It is firm but bendable, and it is covered by skin that has a rich supply of blood vessels. Ideally, the nasal septum lies exactly in the center so that the left and right sides of the nose are of equal size. In about 80% of the population, this nasal septum is a little off-center but not noticeable. However, if this off-centering is more pronounced, it is known as a deviated septum. An operation to straighten the nasal septum is known as a septoplasty. A perforated nasal septum can be caused by an ulcer, trauma due to an inserted object, long-term exposure to welding fumes, or cocaine use. There is a procedure that can be of help to those suffering from the perforated septum. A silicone button can be inserted in the hole to close the open sore. The nasal septum can be affected by both benign tumors such as fibromas, and hemangiomas, and malignant tumors such as squamous cell carcinoma.

Cosmetic procedures A nasal septum piercing is usually carried out through the fleshy columella close to the end of the nasal septum.

References

This article incorporates text in the public domain from page 993 of the 20th edition of Gray's Anatomy (1918)

External links

Anatomy figure: 33:02-01 at Human Anatomy Online, SUNY Downstate Medical Center – "Diagram of the skeleton of the medial (septal) nasal wall" Diagram at evmsent.org lesson9 at The Anatomy Lesson by Wesley Norman (Georgetown University)

Illustrations

Nasal septum: Vomer of infant — Vomer of infant

Worked examples

Example 1 — a first encounter with Nasal septum

Start with the simplest possible case. Write down what Nasal septum claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 Nasal septum 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 Nasal septum 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 Nasal septum

In research: Nasal septum appears in science 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 Nasal septum 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: Nasal septum is common in secondary-school and first-year university syllabi. It links to neighbouring topics Nose, Otorhinolaryngology, so understanding it makes those chapters shorter.
In everyday life: Look for Nasal septum 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 Nasal septum in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Nasal septum 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 Nasal septum out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Nasal septum in simple terms?

The nasal septum (Latin: septum nasi) separates the left and right airways of the nasal cavity, dividing the two nostrils. It is depressed by the depressor septi nasi muscle.

Why does Nasal septum matter?

Because it connects several science 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 Nasal septum?

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 Nasal septum.