science

Lateral corticospinal tract

Lateral corticospinal tract 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 Lateral corticospinal tract rather than just read about it. In short: The lateral corticospinal tract (also called the crossed pyramidal tract or lateral cerebrospinal fasciculus) is the largest part of the corticospinal tract. It extends throughout the entire length of the spinal cord, and on transverse section appears as an oval area in front of the posterior column and medial to the posterior spinocerebellar tract.

Key takeaways

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

Reference excerpt

The lateral corticospinal tract (also called the crossed pyramidal tract or lateral cerebrospinal fasciculus) is the largest part of the corticospinal tract. It extends throughout the entire length of the spinal cord, and on transverse section appears as an oval area in front of the posterior column and medial to the posterior spinocerebellar tract.

Structure Descending motor pathways carry motor signals from the brain down the spinal cord and to the target muscle or organ. They typically consist of an upper motor neuron and a lower motor neuron. The lateral corticospinal tract is a descending motor pathway that begins in the cerebral cortex, decussates in the pyramids of the lower medulla (also known as the medulla oblongata or the cervicomedullary junction, which is the most posterior division of the brain) and proceeds down the contralateral side of the spinal cord. It is the largest part of the corticospinal tract. It extends throughout the entire length of the medulla spinalis, and on transverse section appears as an oval area in front of the posterior column and medial to the posterior spinocerebellar tract.

Function Axons in the lateral corticospinal tract weave out of the tract and into the anterior horns of the spinal cord. It controls fine movement of ipsilateral limbs (albeit contralateral to the corresponding motor cortex) as it lies distal to the pyramidal decussation. Control of more central axial and girdle muscles comes from the anterior corticospinal tract. Damage to different parts of the body will cause deficits, depending on whether the damage is above (rostral) or below (caudal) the pyramidal decussation. Damage to the body above the pyramidal decussation will cause contralateral motor deficits. For example, if there is a lesion at the pre-central gyrus in the right cerebral cortex, then the left side of the body will be affected. Whereas damage below the pyramidal decussation will result in ipsilateral motor deficits. For example, spinal cord damage on the left side of the lateral corticospinal tract at the thoracic level can cause motor deficits to the left side of the body.

Clinical significance Strokes, spinal muscular atrophy, Brown Sequard Syndrome, poliomyelitis and amyotrophic lateral sclerosis are all pathologies that could affect the lateral corticospinal tract. Damage to the lower motor neurons could pose a risk of muscle atrophy and other disorders.

Additional images

References This article incorporates text in the public domain from page 759 of the 20th edition of Gray's Anatomy (1918)

External links

hier-798 at NeuroNames Overview at thebrain.mcgill.ca Illustration and text: sc97/text/P4/intro.htm at the University of Wisconsin-Madison Medical school

Illustrations

Worked examples

Example 1 — a first encounter with Lateral corticospinal tract

Start with the simplest possible case. Write down what Lateral corticospinal tract 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 Lateral corticospinal tract 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 Lateral corticospinal tract 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 Lateral corticospinal tract

In research: Lateral corticospinal tract 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 Lateral corticospinal tract 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: Lateral corticospinal tract is common in secondary-school and first-year university syllabi. It links to neighbouring topics Motor system, Spinal cord tracts, so understanding it makes those chapters shorter.
In everyday life: Look for Lateral corticospinal tract 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Lateral corticospinal tract” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Lateral corticospinal tract in 20 minutes

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

Frequently asked questions

What is Lateral corticospinal tract in simple terms?

Why does Lateral corticospinal tract 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 Lateral corticospinal tract?

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 Lateral corticospinal tract.