science

Transversus thoracis muscle

Transversus thoracis muscle 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 Transversus thoracis muscle rather than just read about it. In short: The transversus thoracis muscle (), also known as triangularis sterni, lies internal to the thoracic cage, anteriorly. It is usually a thin plane of muscular and tendinous fibers, however on athletic individuals it can be a thick 'slab of meat', situated upon the inner surface of the front wall of the chest.

Key takeaways

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

Reference excerpt

The transversus thoracis muscle (), also known as triangularis sterni, lies internal to the thoracic cage, anteriorly. It is usually a thin plane of muscular and tendinous fibers, however on athletic individuals it can be a thick 'slab of meat', situated upon the inner surface of the front wall of the chest. It is in the same layer as the subcostal muscles and the innermost intercostal muscles.

Structure It arises on either side from the lower third of the posterior surface of the body of the sternum, from the posterior surface of the xiphoid process, and from the sternal ends of the costal cartilages of the lower three or four true ribs. Its fibers diverge upward and lateralward, to be inserted by slips into the lower borders and inner surfaces of the costal cartilages of the second, third, fourth, fifth, and sixth ribs. The lowest fibers of this muscle are horizontal in their direction, and are continuous with those of the transversus abdominis; the intermediate fibers are oblique, while the highest are almost vertical. This muscle varies in its attachments, not only in different subjects, but on opposite sides of the same subject. The muscle is supplied by the anterior rami of the thoracic spinal nerves (intercostal nerves).

Function Contraction of transversus thoracis aids in forced expiration. Examples of forced expiration include laughing, coughing, and sneezing. It acommoplishes this action by decreasing the transverse diameter of the thoracic cage.

Additional images

References This article incorporates text in the public domain from page 403 of the 20th edition of Gray's Anatomy (1918)

External links Anatomy photo:18:05-0104 at the SUNY Downstate Medical Center - "Thoracic Wall: Removal of Intercostal Muscles" thoraxmuscles at The Anatomy Lesson by Wesley Norman (Georgetown University)

Illustrations

Worked examples

Example 1 — a first encounter with Transversus thoracis muscle

Start with the simplest possible case. Write down what Transversus thoracis muscle 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 Transversus thoracis muscle 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 Transversus thoracis muscle 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 Transversus thoracis muscle

In research: Transversus thoracis muscle 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 Transversus thoracis muscle 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: Transversus thoracis muscle is common in secondary-school and first-year university syllabi. It links to neighbouring topics Muscle stubs, Muscles of the torso, so understanding it makes those chapters shorter.
In everyday life: Look for Transversus thoracis muscle 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 Transversus thoracis muscle in 20 minutes

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

Frequently asked questions

What is Transversus thoracis muscle in simple terms?

Why does Transversus thoracis muscle 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 Transversus thoracis muscle?

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 Transversus thoracis muscle.