GASTRULATION OF AMPHIBIANS (FROG)
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- Опубликовано: 20 окт 2024
- Gastrulation
INTRODUCTION
In frog development, a zygote undergoes a series of cell divisions that result in the formation of a blastula, a fluid-filled ball of cells. Based on the pattern of cleavage, the cells of the blastula, called blastomeres, contain cytoplasm with slightly different contents. Some of these blastomeres are essential in triggering the next phase of development, called gastrulation.
In gastrulation, the blastula rearranges, with sheets of blastomeres from the outside of the embryo entering the embryo’s interior. Cells move into contact with new cells, allowing unique intercellular communications that lead to cell determination and differentiation. By the end of gastrulation, three embryonic germ layers-endoderm, mesoderm, and ectoderm-take their positions in the embryo. These layers ultimately give rise to specific tissues and organs that make up the adult body plan.
1
If we look at a cross section of an embryo of the frog Xenopus, we can see that at this point it is a ball of cells with a fluid-filled cavity. The cavity is the blastocoel, and the embryo is in the blastula stage of development. A blastula contains large yolk-filled cells at the vegetal pole and smaller cells at the animal pole.
2
The three colors represent the three tissue layers that become defined early in embryogenesis. Yellow indicates endoderm, red indicates mesoderm, and blue indicates ectoderm.
3
At the beginning of gastrulation, a few surface cells, called bottle cells, move into the interior of the embryo, followed by other surface cells. We can track the movement of cells into the embryo if we add dye to a few surface cells.
4
The movement of cells into the embryo creates a lip, called the dorsal lip, over which sheets of cells continue to move inside. At the same time, the ectoderm extends around the embryo’s surface in a process called epiboly. As gastrulation proceeds, a cavity, called the archenteron, forms while the blastocoel shrinks.
5
The archenteron is the primitive gut and is completely surrounded by endodermal tissue. The endoderm at the roof of the cavity originated from the outside of the embryo. The cavity is continuous with the outside, via the blastopore, which eventually becomes the anus of the animal.
6
As the ectoderm extends around the embryo, another set of bottle cells forms. These cells migrate into the embryo, and other surface cells follow them, creating the ventral lip of the blastopore.
7
By the end of gastrulation, the ectoderm has surrounded the embryo, endoderm lines the inside, and mesoderm lies between the two. Additionally, the fates of specific regions have become determined.
8
The endoderm gives rise to the digestive and respiratory tracts and associated structures. The mesoderm gives rise to the skeleton, circulatory system, muscles, excretory system, and most of the reproductive system. The ectoderm gives rise to the skin, sense organs, and nervous system.
CONCLUSION
Developmental biologist Lewis Wolpert said about gastrulation, "It is not birth, marriage, or death, but gastrulation, which is truly the most important time of your life."
Although humans and frogs differ greatly in the structure of the blastula (called a blastocyst in humans) and in the process of gastrulation, in each case gastrulation sets the stage for the formation of the adult body. In gastrulation, the three embryonic tissue layers move into the positions where they begin to develop into the adult’s organs and tissues.
In the accompanying animation, we examined gastrulation in the frog. In this process, endodermal tissue migrates from the surface of the embryo to the interior. Ectodermal tissue extends around the embryo by the process of epiboly. Mesodermal tissue extends from a band of tissue to take its place between the endoderm and ectoderm. The primitive gut-the archenteron-forms while the blastocoel recedes. In frogs and other animals of the deuterostomate lineage, the blastopore eventually develops into the anus of the animal.
The following is a list of the adult tissues and organs that develop from the three embryonic tissue layers:
Ectoderm
Brain and nervous system; lens of the eye; inner ear; lining of mouth and nasal canal; epidermis of skin; hair and nails; sweat glands; oil glands; milk secretory glands
Mesoderm
Skeletal system (bones, cartilage, notochord); gonads; muscle; outer coverings of internal organs; dermis of skin; circulatory system (heart, blood vessels, blood cells); kidneys
Endoderm
Inner linings of gut; respiratory tract (including lungs); liver; pancreas; thyroid; urinary bladder
it's well made bro, thank you a lot for this animated video. It helps a lot understanding the phenomenon
It's been so many years. Still the best video on RUclips ever.
Best Video On RUclips.
Well Explained.
Short and Easy To Understand.
Best video ever
I understand in few minutes what i didn't understand it in 1 hour thank you⭐⭐
Thank You Nancy.
People Like You Made My Day ☀️
Thank you for the video!!!
I finally understood!
Thank you, perfect and simple explanation!
GOATED thank you so much for this video!
Muchas gracias ❤ Está muy bien a animado y explicado el proceso. Mi profe me pasó a mi y a mis compañeros varios links para nuestras exposiciones.
Gracias por ver a Lady Random 🥰
Extremely well explained! Kudos
sr if u ll make futher little more about frog complete development.very understood
If we looked at the cross section of embryo of fray, a ball of cell with fluid filled carly. Lan See pasto coel, and emriyo is in blastula stage of development.
Blastula contain large yolk filled cells at vegetal pole and small cell on animal pole
At the begining of gastrulation a few surface cells called bottle
cells, move into the embryo, followed by anterior of the other surface cells..
We can track the movement of cells into the embryo, It we have died a few surface cells. The movement of the cells into the emayo creat a lip called the dorsal lip, over which the sheet of cells continue to move inside. At same time ectoderm extends around the embryo Surface in a process called epiboly. As the gastrulation proceed a cavity called the archenteron formed, and blastocoel Progressively shrinks.
Archenteron is primitive gut and
surrounded by endodermal tissue The
Cavity continues with the outside. where the blastopore, which eventually become the annus of the animal. As the endoderm extend around the embryo, another set of bottle cells formed - These calls migrate to the embryo, another surface cells
follow them creating ventral lip of the blastopore.
At the end of the gastrulation the "ectoderm Surrounded the embryo. endoderm surrounds the inside. mesoderm lines b/w two. Additionally the fate of
specific regions become determined.
Endoderm give rise-digestive respiratory tract and associated structures.
Mesoderm...give rise to Skeleton, Circulatory system muscles & excretory syste. and most of Reproductive system. Endoderm-) give rise to Skin, Sense
organ & nervous system.
Hi, I come from Thailand! this video makes me understand the lesson. Thank you!
ขอบคุณมาก. คนอย่างคุณทำให้วันของฉัน 💥
Keep uploading more!
So fruitful..
Love from nepal🇳🇵💗
I'll After My Exams. Studying Right Now.
An awesome explanation of gastrulation ❤❤❤❤thank u sooo soo much it was really very helpful ❤❤❤❤#Love from Pakistan 🇵🇰🇵🇰
Thanks to you for watching and commenting on this video. ❤️
Very Good Explanation ❤
Precise and crisp... Thanku
Happy2Help 😊
찐이다.... 감사합니다 이해가 아주 잘 됐어요ㅎㅎ
Can You Please Translate Your comment in English ?
The Optimized Brain Awesome... Thank you. This video is very helpful for understanding.
Thanks
Thank you so much man
Thanks sir for the video and notes 📝
Nice video
Shukriya ❤️
😍It's a nice vedio. Easily understandable. Thank you 😘
Happy Learning ❤️
At which of these cell stage of frog blastula a blastocoel is formed?
Everything is Explained in Description 😅
What is the secondly-made space under the ventral lip? is it aslo protogastor? I thought there’s only one protogastor in the embryo
Thank you !🙏🏼
😊
short but useful 👍
thank you!
Thisis great! Thanks
🤗
Wooow thanks
Zetta Crest
Verry nice..
Understood
Bro, amazing video.. made me understand within no time...
what's the source of this video?
It's a Paid Content. Providing You Guys for free.
How can i get it if i want it by paying??
@@SHADOW_GAMINGrtx4060 those animation content makers should upload it free on youtube actually. In this way, they can edycate the whole world for free! Nothing can be more philanthropic than that!
Thankss
I came here looking for an Amphibia map
and then you find something Beautiful 😍
Mesoderms come from micro or macromere ?!
Looks like micromers
From macromeres
The mesoderm comes from the marginal zone of the blastula.
If the blastopore was an anus, then where is the origin place that mouth has developed? is it ventral lips or at another end of the archenteron? (sorry for my bad English)
Read Description Please and Then watch video again.
Казалось бы, причём здесь Украина
Cô ơi em xem rồi nha ạ!
Can You Please translate this comment to English.
Thank You.
@@SHADOW_GAMINGrtx4060 Dear teacher! I saw this video! Thanks you!
Also Write this video down with your hands if u want to learn this concept for lifetime.
Thank You.
Plz explain in hindi
Soon Mam.... Right now I'm busy. #exams
I'll be Uploading Videos in Hinglish Language... So Stay Tuned.
#HappyLearning
Do you need hindi translation of this video notes ??
Who's is here from St Mary's College ❤
Biologists shouldn't even be allowed the job of naming things IMO. The naming NEEDS to be done by physicists because it has really gotten out of hand...
thats what im saying
what is hard in the names? it actually has a meaning, ectoderm = ecto + derm (ecto = εκτος (greek word for outside)) derm = δερμα (derma) greek for skin/tissue, meso = middle, endo = inside
how so?
Yeah and doctors shouldn't be allowed to operate on humans, astronomers should do that.
🇺🇦🥚 )))
Thanks
Thanks!
Thanks for watching 👆