シャドーイング練習: SVINutes: Cerebral Venous Sinus Anatomy - 動画で英語スピーキングを学ぶ

Hi, thank you for tuning into this minute on venous sinus anatomy.

So we're going to jump right in.

And the most important thing to frame our discussion today is to really understand the circulation for the venous system.

So that starts with understanding that the cerebrospinal fluid is predominantly made in the choriole plexus of the lateral ventricles.

and then from there it's going to bathe the brain, flow through the cisterns, and then be absorbed through the arachnoid granulations.

So this really shows how those arachnoid granulations are jutting into each one of those venous sinuses,

and then from there the peripheral venous sinuses are predominantly going to drain from anterior to posterior,

then around the sides of the ears and down the jugular vein.

We're going to go through all of those details in the next slides.

So first we need to remember that the venous sinuses are not like arteries.

They are not pipes.

They are instead spaces that are created between the dural leaflets.

So between the periosteal layer aligning the skull and between the meningeal layer aligning the surface of the brain.

And so because of that, as this slide is showing, they end up being a series of trabeculated spaces.

They're not just one big open channel and they're not all created alike because of that.

Also, you'll note the arachma granulation is jutting into those channels, which also can change the shape and the size of each one of those sinuses.

Now that's true for the peripheral sinuses, like I just showed you, as well as for the deep sinuses.

So in this slide this is the cavernous sinus with both a diagram

and an angiogram side by side just to show that true trabeculation

and that when you're traversing these spaces they are not just one big open tube

but instead of more like finding the holes in Swiss cheese.

So let's get through the the sinuses and the venous drainage.

So starting with the peripheral anatomy what you can see at

the top of the slide here is the superior sagittal sinus

that's going to collect the venous drainage from the cortical veins starting anteriorly

and then draining posteriorly back to the confluence of sinuses from

the confluence you're going to drain both sides down the transverse sinuses out laterally

and then down the sigmoid sinus into the jugular vein now those peripheral

that peripheral drainage is going to be met by the deep venous drainage as well.

So we're going to introduce that on this slide and then go into some details.

So you're going to have the inferior sagittal sinus that's going to be lining the corpus callosum, so again that same c-shape going from anterior to posterior.

When it gets down to the inferior border it's going to connect to that confluence by the straight sinus,

again draining by the sigmoid sinuses and down the jugular vein.

The other deep venous structures, which you can see here in the diagram we'll look at on this next slide.

So predominantly we're talking about the internal cerebral veins and those are bilateral, the paired structures as well as the basal vein of Rosenthal, again bilateral.

They're going to converge to create the great cerebral vein of Galen

and then that is also going to empty into the straight sinus.

So let's look at those individually.

So for the internal cerebral vein, you want to think of that as draining all of the midline deep structures.

So things like the fornix,

the amygdala, the hippocampus, and of course the thalamus are all going to drain into those internal cerebral veins bilaterally,

as opposed to the basal vein of Rosenthal, which is going to start collecting blood as anterior as the anterior cerebral veins,

and then it's going to migrate back and around the cisterns

and connect to that internal cerebral vein to create the vein of Galen.

Now, it's important to note that each one of these sinus systems, both the deep sinus system and the superficial sinus system, both have anastomosis.

So what I'm showing on this slide is the convergence of the superficial anastomosis.

So that's going to be the superior cerebral vein, which is going to come in from the anterior surface.

And it's going to anastomose with the vein of Trollard, which is going to be your predominant cortical vein that goes to the superior sagittal sinus.

And with the vein of which is going to be your predominant venous drainage going into the transverse sinus.

Now it's important to note that this is very uncommon pattern that I've shown here on the angiogram or the venogram, where all three are about the same size.

They're all co-dominant truly.

Usually one is much larger, another smaller, and just remember that that flow can go anterior

and posterior through each of those channels to either drain through the more anterior deep drainage or more superficial posterior drainage.

Now those variations

we see every day and so this is an example of the transverse sinuses

which in panel C are truly co-dominant

but more commonly one is going to be dominant

and the other one not and so that's what you're seeing in A

and B where A the left transverse sinus is going to be the dominant drainage

and and be the right transverse sinus is going to be the dominant drainage.

And so we see this on imaging every day, but the key is to note that it can actually create pathology.

So if you couple that with, for instance, an arachnid granulation at the transverse sigmoid junction, like in this slide, what you can see is that in this person,

the left transverse sinus was the non-dominant sinus.

The dominant drainage was through the right transverse sinus, and then you got this pinch point from that arachnoid granulation.

So the pressures are shown on this slide and you can see

that this person had intracranial hypertension with a pressure of 45 in the spherosagittal sinus

but then we were able to stent that sinus to release

that pressure and the pressure did normalize on the right side of the screen as soon as that stent was placed.

So just to summarize what I've shown you, hopefully everybody can recognize some of the major cerebral veins and

and the venous sinus drainage for both the superficial and deep venous sinus systems.

There's much more complicated anatomy involved, but this gives you a kind of a high level overview.

And so I thank you for taking the time and I hope you've enjoyed this minute.

シャドーイングとは？英語上達に効果的な理由

シャドーイング（Shadowing）は、もともとプロの通訳者養成プログラムで開発された言語学習法で、多言語習得者として知られるDr. Alexander Arguelles によって広く普及されました。方法はシンプルですが非常に効果的：ネイティブスピーカーの英語を聞きながら、1〜2秒の遅延で声に出してすぐに繰り返す——まるで「影（shadow）」のように話者を追いかけます。文法ドリルや受動的なリスニングと異なり、シャドーイングは脳と口の筋肉が同時にリアルタイムで英語を処理・再現することを強制します。研究により、発音精度、抑揚、リズム、連音、リスニング力、そして会話の流暢さが大幅に向上することが確認されています。IELTSスピーキング対策や自然な英語コミュニケーションを目指す方に特におすすめです。

シャドーイング練習: SVINutes: Cerebral Venous Sinus Anatomy - 動画で英語スピーキングを学ぶ

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シャドーイングとは？英語上達に効果的な理由