3D Body Cavities Embryology Part 1: Embryonic Folding - Pericardioperitoneal canals

In this video Dr. Aizaz from MedicoVisual talks about Embryogeneiss of Body cavities using 3D graphics. Body cavities include pericardial cavity, pleural cavity and peritoneal cavity
00:00 What is intraembryonic celom and how it develops during second and third week of early embryogenesis?
08:03 Craniocaudal folding of the embryo
10:03 Transverse folding of the embryo
13:26 How u-shaped intraembryonic celom is transformed to body cavities viz., pleural cavity, pericardial cavity and peritoneal cavity
16:20 Why is peritoneal cavity connected with extraembryonic celom at the umbilicus
18:46 What happens to septum transversum during embryonic folding
21:45 Complete overview of body cavities
22:54 Pericardial cavity, Peritoneal cavity and pericardioperitoneal canals
26:25 Origin of Septum Transversum
During the third week of development, the three germ layers are formed, viz., Ectoderm, mesoderm, and endoderm. The mesoderm is not a homogenous layer, but it gets divided into different components. The medial most is paraxial mesoderm, the lateral most is lateral plate mesoderm and in between them is the intermediate mesoderm.
Small spaces arise within the lateral plate mesoderm. These spaces then coalesce to form a larger, continuous cavity called intraembryonic celom. Thus, splitting the lateral plate mesoderm into two layers. The layer that underlies the ectoderm is intraembryonic somatopleuric mesoderm and the layer that covers the endoderm is intraembryonic splanchnopleuric mesoderm.
As you must be knowing, from the lecture of 2nd week of development (and if you don’t know please watch that lecture first), that the embryo with its amnion and yolk sac cavity is surrounded from the outside, by a mesoderm. Since this mesoderm is outside of the embryo proper, it is called EXTRA-Embryonic mesoderm. This mesoderm too, develops spaces that coalesce to form the celomic cavity termed as extraembryonic celom. No such space develops at the connecting stalk. Please note that the extraembryonic mesoderm that underlies that chorion is extraembryonic somatic mesoderm. The extraembryoic mesoderm’s layer that covers the amnion is also the somatic layer. However, one that covers the yolk sac is splanchnic layer.
Now the intraembryonic splanchnopleuric mesoderm is continuous with the extraembryonic splanchnopleuric mesoderm and similarly the intraembryonic somatopleuric mesoderm is continuous with the extraembryonic somatopleuric mesoderm.
The intraembryonic celom is an inverted U-shaped cavity that is peripherally continuous and connected to the extraembryonic celom, except at the cranial midline where the intraembryonic mesoderm is not split. Here, there is a block of tissue called septum transversum. There are two hypotheses for its origin. One is simple that here that intraembryonic mesoderm is not split between splanchnic and somatic and the other is that intraembryonic splanchnic mesoderm proliferates to form the septum transversum.
So intraembryonic and extraembryonic celom have wide communication peripherally except at the site of septum transversum. It is worth mentioning here that according to some well-known embryologists, it is only the distal part of the limbs of inverted U-shaped intraembryonic celom that is in direct connection with extraembryonic celom. The midline and the proximal part of the limbs are not connected to the extraembryonic celom. The midline part of the intraembryonic celom is the primordium of pericardial cavity while it’s limbs are the primordium of pleural and peritoneal cavities. And if you are wondering how is that so? Don’t worry it will make sense in a few minutes.
With the craniocaudal and lateral folding of the embryo, this intraembryonic celom is drastically remodeled.
With the cranial folding the, the central midline of inverted U-shaped intraembryonic celom is bend cranially in such a way that it lies in front of (or, you can say, ventral to) the foregut.
With the transverse of lateral folding, lateral margins of the intraembryonic celom comes to meet at the ventral midline. Here the fuse, except at the region of midgut. At the region of midgut, they cannot fuse due to presence of vitelline duct.

[@MedicoVisual]

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[@antonyshigin4977]

Evertime you start any embryology lecture, you often revise from the beginning... I find it really useful sir... It helps me to recall what I have learnt before...Thank you so much Sir...❤ from 🇮🇳

[@ashiqhussain6956]

Excellent lecture Dr Aizaz 👌

[@tahiraaslam6075]

Best ever animation and explanation..

[@prachijaiswal9233]

This is the best way to teach embryology These videos had clear all my doubts😊😊

[@MedicoVisual]

Glad to hear that

[@abdoudjender1785]

these videos saved my life!!! thank you doctor. mashallah

[@naijawhatis]

Thank you sir ❤

[@Kimia-vu3hv]

Thank you ❤ Love from Iran ❤

[@achritam]

Nice illustrations

[@user-lr5bm5gz2o]

Nice Presentation

[@evchenbaumi5054]

excellent video

[@rafihadar5286]

Thx

[@deepgaming1360]

You are a LEGEND!!!!!!

[@MedicoVisual]

Thank you so much.

[@shreyasph1272]

Most effective way of teaching

[@MedicoVisual]

Thanks a ton

[@oleg_prikhodko]

Thank you, Dr. Aizaz!

[@OmusawoGeraldMassa]

Thanks for this lesson

[@MedicoVisual]

Always welcome

[@EzeKidochukwu]

Intrembryonic mesoderms are continuous with the splanchnic of extraembryonic mesoderm. Since the somatic extraembryonic mesoderm is only continuous to the splanchnic extraembryonic mesoderm by connecting stock. Please check this out

[@MedicoVisual]

Thank you so much for pointing it out. Can you please share a relevant reference?

[@vicktorshushackov3074]

Hello. I'm a medical student from Russia, and I love your videos. Thanks you so mutch, you're a wonderful lector

[@agersolt818]

о, я тож из России

[@vicktorshushackov3074]

@@agersolt818 я из Омска, лечфак, 3 курс

[@agersolt818]

@@vicktorshushackov3074 Я из Москвы, леч, 4 курс

[@agersolt818]

@@vicktorshushackov3074пытаешься тоже вникнуть в эмбриологию?

[@vicktorshushackov3074]

@@agersolt818 ага, для себя. Мы уже сдали её, но на парах не очень понял

[@chineduokafor6763]

Genius even better than the texts

[@jessicasandhu1858]

@Medicovisual sir this means at 7.37 min mesoderm is invaginating buccopharyngeal membrane also

[@MedicoVisual]

Actually this is not the perfect model. At buccopharyngeal membrane and cloacal membrane, there is little to no mesoderm. Thank you so much for pointing this out. I should have fixed it in the model. But since this was not the main topic, it was overlooked. I am sorry.

[@the_hellfire7581]

Thank you very much 😊 I also wanna become a doctor.

[@MedicoVisual]

Most welcome 😊

[@henryunachukwu3232]

❤

[@osamarao7699]

❤❤❤

[@tomcruise9317]

🤩

[@tamilspeaker2507]

Sir at 8:12 , the cranial part of embryo ( near oropharyngeal memb ) have paraxial mesoderm , intermediate mesoderm and lateral plate mesoderm at midline of cranio-caudal axis . So ,this means the intra embryonic mesoderm will be lateral upto presence of notochord . Then , it move towards midline covering notochord cranially . Am I correct sir

[@MedicoVisual]

Yes that correct. There are right and left limbs of mesoderm that converge in the cranial midline to form unfused cranial midline part.

[@preciousibom7484]

Did you do a graphics design degree before the medical degree dr? 😮

[@MedicoVisual]

No. I do not have a graphics design degree. I self-learned blender from KZbin and Udemy.

[@houriak848]

Hello sir in which lecture u discussed about septum transversum ?

[@MedicoVisual]

In this lecture from 26:26 onward and in GIT Embryology course with development of liver.

[@RyanKoh-tv2rj]

Is it possible to share the blender file, this is too amazing to miss out on

[@MedicoVisual]

Thanks for watching and leaving a comment! Please let me know for what purpose do you need the .blend file? Feel free to contact me directly via any one of the following channels: 1. Live chat at www.medicovisual.com 2. WhatsApp text at [phone]. Email at [e-mail] 4. Contact us form at www.medicovisual.com Best regards, Dr. Aizaz

[@prof.dr.naseemahmed6050]

10.45: transverse section or coronal section?

[@MedicoVisual]

Transverse section

[@akbashirahmad]

How's it possible that in a longitudinal section all the three portion of mesoderm i. e., The paraxial mesoderm, the intermediate mesoderm and lateral plate mesoderm are visualized???

[@MedicoVisual]

I am sorry, I didn't quite understand your question. Can you please elaborate how and why all three portions of mesoderm cannot be visualized. Also please include the timestamps of the video and if necessary, references from a book.

[@akbashirahmad]

@@MedicoVisual I'm saying in midline is notochord, slightly lateral to it's paraxial mesoderm, then intermediate mesoderm and lateral most is lateral mesoderm,,, so if we take longitudinal section of Embryo will we be able to see all the three division of mesoderm in longitudinal section? It's not possible... But, it's possible to see 8n transverse section

[@akbashirahmad]

During 8-9 minutes.... During craniocaudal folding

[@MedicoVisual]

@@akbashirahmad okay I got you. But why do you think it's not possible to visualize different parts of mesoderm in this section?

[@akbashirahmad]

@@MedicoVisual Sir, I might be wrong...But the reason why I'm saying we can't visualize all the three mesodermal portions in longitudinal section is that they're not all present in some longitudinal plane... Paraxial mesoderm being medial most, slightly lateral to it's intermediate mesoderm, while lateral most is Lateral mesoderm,,,, so if I think a longitudinal section I can't see all the three.... Please do correct me if I'm wrong!

[@mirshahanmehsud7727]

Sir how can we get your 3d sofmodels🥺

[@MedicoVisual]

I am sorry. These 3D models aren't available, as of now.

[@7atwkhod519]

This program name please?❤

[@MedicoVisual]

Blender 3D

[@waelsp584]

What is name of this app ?😮

[@MedicoVisual]

It's a software called "Blender 3D"

[@user-fy6so2xb4p]

What that app you have used?!

[@MedicoVisual]

It's a software called "Blender"

[@MuthuThala-ih2wu]

Not at all intuitive.. Messed up everything Ur just complicating that topic Dont zoom past, no clear visual of coleomic cavities during folding, no ecto, endoderm and extra embryonic mesoderm during folding......

[@MedicoVisual]

Dear @MuthuThala-ih2wu, Thank you for your feedback on my lecture. I apologize if the explanations and visuals were not clear or intuitive enough. Your input helps me identify areas for improvement. I will review the sections you mentioned and work on providing more detailed and understandable explanations in future lectures, particularly regarding the coelomic cavities, embryonic folding, and the roles of the germ layers. If you have any specific suggestions or questions, please feel free to share them. I appreciate your engagement and am committed to supporting your learning journey. Best regards, Dr. Aizaz

[@MuthuThala-ih2wu]

@@MedicoVisual include extra embryonic mesoderm, ectoderm, endoderm during embryonic folding. After 20 mins video got too complicated bcoz of u not explaining about it properly. All ur videos are Intuitive, except these embryonic foldings...

[@MedicoVisual]

@@MuthuThala-ih2wu Thank you for your comments. I will try to create separate lectures specifically on the Embryonic folding that will include all the structures in the animation.