The study of the development of an embryo from fertilisation through to description as a foetus.

learn more… | top users | synonyms

0
votes
1answer
13 views

What is Saccus in Embryology?

The word seems to be of German origin. I have it here Saccus lymphaticus inguinalis, Saccus lymphaticus jugularis, Saccus lymphaticus posterior, Saccus lymphaticus retroperitonaealis. I ...
0
votes
0answers
8 views

What are things inside dorsal aorta in germ layers?

I am not sure if they are mesonephros. Mesonephros should be above dorsal aorta, not visible in this picture. What are those cells inside the red shaped circle?
0
votes
1answer
25 views

Development of vitreous humor

I have tried reading about development of vitreous humor but it is all very confusing. When does it first developed ? Does it renew itself ? Please provide reliable sources..
2
votes
1answer
20 views

Roles of creatine and bilirubin in foetus circulation

I think they are not inputs from maternal placenta. I think they are the results of foetus metabolism. However, I do not understand it how and where exactly. What are the roles of creatine and ...
4
votes
3answers
99 views

Does our eyeball increase in size as we grow?

Does the size of the eye increase as we develop from the stage the complete eye first forms to infancy and then to adulthood ?
0
votes
0answers
7 views

Does dark blastomere precede embryoblast?

I am thinking the stage from morula into blastocyst where the Zona pellucida dissolves and develops a cellular ring (trophoblast) around the blastocyst. Does dark plastomere develop into ...
0
votes
1answer
28 views

Manifestations of open foramen ovale in adults

I read that foramen ovale opens in 30% of adults. I do not know how much of these openings can then close again. Probably, none. It is not pathogenic if no symptoms. It allows blood to enter from ...
-1
votes
1answer
31 views

What is this abbreviation CT in female reproductive system

I have this sentence in my notes Ovary is surrounded by tunica albuginea and the cortex keeps the primordial follicles. The medulla containing CT and blood vessels develop from mesonephros. I ...
0
votes
0answers
7 views

What is CT of tertiary villus in placental barrier?

Context Placental barrier consists of CT of the tertiary villi. It something Chorionic ... I think it cannot be cytotrophoblast because it does not have tertiary villus. If it was, it would ...
1
vote
1answer
24 views

Mutated Sperm - What happens?

I saw on TV that not all sperm are the same. Some have mutations like 2 and 3 tails? There were other mutations as well. If one of these mutated sperm actually fertilized an egg, would the embryo ...
1
vote
2answers
25 views

Is there any bank of animations for Embryology?

I am trying to find animations which can anonymous or generalised for Embryology. However, I have not find any single good source. Is there any bank of animations for generalised embryos?
1
vote
1answer
12 views

Function and process of TCTE-1 receptor

I was wondering if anybody knew of the function and process of the TCTE-1 receptor during the binding of a sperm with an egg. The only think I know of TCTE-1 is that it is a species-specific receptor. ...
1
vote
1answer
11 views

Significance of prostaglandins in semen?

I am trying to figure out how prostaglandins in the semen relate to the female reproductive tract. More specifically, How does prostaglandins in semen help the female reproductive tract increase the ...
1
vote
0answers
26 views

Purpose of certain genes in embryonic development [closed]

(Please correct me if I'm wrong on any count here). As I understand it, development requires the action of numerous genes and proteins. My textbook has described it as being almost reminiscent of a ...
0
votes
0answers
8 views

To visualise the embryonic development of skeleton and muscles?

I am trying to find a visualisation for this topic, preferably a video. Some facts which I would like to have in the video(s)/visualisation Ossification starts usually with 3 primary centers: 1 ...
1
vote
1answer
28 views

What's the difference between an embryo and a fetus?

The most I've been able to come up with is that fetuses are embryos slightly farther along in their development. Is that correct? Thanks! evamvid
0
votes
1answer
16 views

Is endoderm visible in the germ layer?

This picture is my drawing about germ layer - not embryonic folding as I wrote initially. Where exactly is the endoderm here in the picture? The known things Ectoderm Neural tube Notochord ...
0
votes
1answer
50 views

Some trophoblast excreting digestive enzymes in implantation

I found this paragraph in my study materials about implantation Original Simplest trophoblast excretes trypsin related substances and embedding consists of 3 stages: The blastocyst ...
4
votes
1answer
95 views

Causes of monozygotic twins

Twins could be monzygotic i.e. identical twins and dizygotic i.e. non-identical twins.Well, monozygotic twins occur when a single egg is fertilized to form a zygote which later divide into separate ...
3
votes
1answer
64 views

Activation Of Embryonic Genome

Embryonic gene activation is a process by which the embryo begins to transcribe its newly formed genome.As the embryonic gene activation occurs during early stages the paternal genome may not have any ...
1
vote
2answers
35 views

Regulation of the replication of mtDNA at embryonic level

While reading an article on mitochondrial inheritance I came across this link. The results state that mitochondrial DNA replication is regulated in different cells of an embryo at different levels. ...
1
vote
0answers
12 views

Cytoplasmic determinants in amphibians

If cytoplasmic determinants are distributed before fertilisation then how can an amphibian's embryo, whose dorsal side is determined after fertilisation develop ?
4
votes
0answers
95 views

Cytoplasmic determinants - protostomes and deuterostomes

Cytoplasmic determinants are spread unevenly in the egg, and so when embryo starts forming (cells start dividing), the determinants are also unequally divided between cell. This unequal distribution ...
4
votes
0answers
35 views

Is telomere shortening consistant over consecutive cell divisions from zygote to a differentiated cell?

Considering the complexity of embryogenesis, a temporal referance would be helpful to coordinate the developmental sequences during embryogenesis and fetal development which is to be completed within ...
2
votes
1answer
167 views

How many consecutive cell divisions are required to form the adult human body from the single cell zygote?

The preferred question would have been what is the total number of cells in a full term human foetus and how many cell divisions are required to reach that number. However estimates of total cell ...
5
votes
2answers
88 views

There are linear and rotary molecular motors in the cells. Do any of them have a fixed or stable frequency or speed?

Are there any linear, rotary or oscillatory molecular motors in the cells which can have fixed frequeny and which can be used as a reference for elapsed time timer? This question is with relevence to ...
6
votes
1answer
148 views

evolutionary reason behind sharing the same path for food and air?

What is the evolutionary reason behind sharing the same path for food and air? For example, we have a nose and lungs, yet they are linked by the pharynx, which is shared with the mouth and ...
1
vote
2answers
38 views

Which part of the genome are the developmental sequences of embryogenesis located?

Which part or parts of the the genome are the sequences located. Are they spread across the chromosomes? If so how are they accessed sequentially with precision during embrygenesis?
1
vote
0answers
49 views

Is there a realtime molecular clock within the genome to co-ordinate the developmental sequences in an embryo?

It is difficult to assume that the massive number of co-ordinated developmental sequences in a developing embryo is controlled by molecular signalling alone. Is anyone aware of a molecular or ...
0
votes
1answer
174 views

When can a virus modify DNA in every cell of a living organism?

I've recently heard about experiments with brain tissue, where a virus is introduced in a rats brain, causing a "glow when electric charge is present" protein to be created. This protein then helps to ...
1
vote
1answer
59 views

What is a zygote?

During fertilization, the nuclear membrane of the pro-nucleus of the ovum and sperm degenerate. Is the cell is stage called a zygote? After the dissolution, mitosis occurs and two cells are formed.Or ...
2
votes
0answers
134 views

which exact mechanism triggers the first cell differentiation after n divisions?

I would like to understand which mechanism triggers the first cell differentiation after n divisions. I read previous articles on SE and Wikipedia articles on cellular differentiation and ...
5
votes
1answer
51 views

How compatible are mammal wombs?

I had read about science working towards the creation of artificial wombs however I wonder how compatible are mammal wombs and connected systems to develop fetuses. What species are so compatible that ...
1
vote
2answers
59 views

Which X-Y chromosomes have the developmental genes for mammals?

I know that for a given mammal, half the chromosomes come from father and half from mother. This is typically denoted as x-y. I've recently read about "toolkit" genes that control how a cell develops ...
5
votes
2answers
330 views

What metabolic activities are performed by a developing human fetus's liver?

I understand that organ function varies with the stages of development. Does a fetal liver EVER perform lipogenesis, gluconeogenesis, make bile, etc? Or does it only begin performing these actions ...
4
votes
1answer
210 views

Why are eggs “egg” shaped?

Is there a reason as to why chickens lay "egg" shaped eggs, as opposed to spherically shaped eggs (or a random shape)? <--- Main Question For extra points (actually just to add more words in ...
2
votes
3answers
81 views

Simulating Cell differentiation

I'm a computer programmer deeply interested in Biology. I wish to write a computer simulation for cell differentiation. I understand there will be seemingly impossible challenges in doing this. But ...
10
votes
1answer
427 views

Could a fetus properly develop in micro/zero-gravity?

I suppose another way of looking at the question is: how important is gravity for the development of mammal fetuses? And if things would go wrong, what sort of things would they be, and what would be ...
9
votes
1answer
1k views

What determines testosterone exposure in womb, baby's genetics or mom's body?

I read this article which has the following quote: The ratio between index and ring finger is believed to be linked to exposure to the male hormone testosterone in the womb. And I wonder what ...
9
votes
2answers
208 views

Do twins “run in the family”?

My wife and I recently found out that we are going to have twins and so nearly everyone asks if we have a family history of twins. Now I know that the answer for me is that it doesn't matter—as ...
12
votes
2answers
706 views

Impact of Alan Turing's approach to morphogenesis

Shortly before his untimely passing, the computing pioneer Alan Turing published his most cited paper The Chemical Basis of Morphogenesis (1952). The central question for Turing was: how does a ...
11
votes
2answers
282 views

Why do pandas have a high probability of giving birth to twins?

According to the BBC documentary "Wild About Pandas", about half of panda birth result in twins. Why do they have such a high probability compared to other mammals? What factor(s) control that ...
3
votes
1answer
252 views

Does chicken embryo form the disc called “discoblast” in the cleavage and blastulation of chicken?

This thread is related to my previous thread which is still unsolved mainly. I need to be able to compare chick and human cleavage and blastulation of zygote. My friend says that Chicken have ...
6
votes
1answer
460 views

What forms the human amniotic sac?

I am trying to understand the formation of embryonic disc for human and chick so the following question is related to here about formation of embryonic disc. I had thought that the amniotic sac forms ...
5
votes
3answers
978 views

Fetal development, gastrulation and embryonic disc

I am completely confused by the images circulating on the internet of human gastrulation. First, lets see how it happens in deuterostomes. This image depicts the process: (image is from Wikipedia) ...
3
votes
1answer
250 views

Where does meiosis II of oogenesis end exactly in tuba uterina - uterus?

I know that metaphase II ends at ampulla tuba uterina, but I am not completely sure where the telophase II ends. Is it in the triangular section of cervix uterii? I just have an intuition that the ...
2
votes
1answer
127 views

Why are Birds and Reptiles with abundant yolk sac polyspermic?

I was given an explanation that birds and reptiles are polyspermic because they have an abundant yolk sac. But how does it explain the thing? Chicken as an adult is not using in my opinion yolk as an ...
5
votes
1answer
146 views

When does Coelom form exactly?

Related to my other question. I know that the coelom is derived from mesoderm. Coelom seems to form during organogenesis within 3rd and 8th week of embryogenesis. However, that answer is not either ...
4
votes
1answer
2k views

Do humans have Coelom?

Kimball Biology 5e says Coelom is the main body cavity of many animals. It is lined with an epithelium derived from mesoderm. Gilbert Embryonal Biology 9e says Coelom is the space between ...
4
votes
1answer
2k views

What are differences between formation of embryonic disc in chick and mammal embryo?

Exam question which got lowest average points in my university: 1/5 average. No markscheme available so my attempt below. I assume that embryonic disk prefers to germ disk such that Formation prefers ...