Changes After Fertilization
Changes After Fertilization
Changes after Fertilization
Implantation: The fertilized egg (zygote) moves down the Fallopian tube and continuously undergoes cell division. Thus it forms a hollow ball of cells, called embryo. The embryo gets embedded in the wall of the uterus, which is thick and has muscles, glands and a large number of blood capillaries. This process is called implantation.
Pregnancy: The developing embryo at first derives nourishment directly from the mother’s blood flowing in the vessels lining the uterine wall. In about three weeks, it starts absorbing food and oxygen through an organ called placenta. The placenta is a disc like organ in the lining of the uterine wall. It has numerous villi, which are in direct contact with the mother’s blood flowing in the uterine wall. These villi provide a large surface area for glucose and oxygen to pass from the mother to the embryo and for wastes produced by the embryo to be passed into the mother’s blood. The embryo is connected to the placenta by a tube called the umbilical cord. By eight weeks, the embryo starts showing human features and is referred to as foetus. The total period of embryonic development, from the time of fertilization to birth, is called gestation period. It is around 280 days, or 9 months, in humans.
Birth: The wall of the uterus develops a thick layer of muscles during pregnancy. At the time of birth, the uterine muscles contract rhythmically and powerfully, causing labour pains to the mother. Finally, the baby is expelled by the contraction of the uterine muscles. This is called birth or parturition.
What happens when the egg is not fertilized: If the ovum is not fertilized in the upper part of the oviduct, it keeps on descending and is finally passed out through the vagina. It remains in the body for about 24 - 72 hours. As an egg is released for fertilization every month, the uterus also prepares itself every month for the implantation of a fertilized egg. The uterus becomes thick-walled and spongy in order to nourish the embryo. If no fertilization takes place, the thick uterine wall is no longer needed. So, it gradually begins to shrink. This shrinkage ruptures its blood vessels. As a result, blood and mucus ooze out of the vagina. This period, which lasts for 3—5 days, is called the menstrual period, and the process is called menstruation. If the ovum is fertilized, it gets implanted in the uterus wall and embryonic development starts. In this case, the uterus continues to develop in order to hold the embryo. And in this case, there is no question of its shrinkage resulting in menstruation.
Development of Embryo
The zygote (or fertilised egg) divides repeatedly to make a ball of hundreds of cells. This is called an embryo. The embryo moves down the oviduct into the uterus. The embryo gets embedded in the soft and thick lining of the uterus (see Figure 8). This is called implantation. When the embryo settles down in the uterus, the woman is said to have become pregnant (or said to have conceived). The embryo starts growing into a baby. The embryo gets food and oxygen from the blood vessels in the lining of the uterus. The cells of embryo begins to form specialised groups that develop into different tissues and organs of the baby. Embryo is an early stage in a developing baby. Thus, an unborn baby at an early stage of development in the uterus is called an embryo. The body features of the unborn baby are not much developed at the embryo stage. The unborn baby remains an embryo in the first eight weeks of pregnancy. A human embryo at 4 to 5 week's development is shown in Figure 9. We cannot identify any body features (hands, legs, head, eyes and ears, etc.) of the developing baby in this embryo.
The embryo continues to grow and develop in the uterus to form a baby. The embryo gradually develops body parts such as hands, legs, head, eyes and ears, etc. An unborn baby in the uterus at the stage when all the body parts can be identified, is called a foetus (The word 'foctus' is pronounced as 'fetus'). A human embryo becomes a foetus after about eight weeks of pregnancy. From about eight weeks until birth, the unborn baby is called foetus (see Figure 10). It takes about 38 weeks (about nine months) from the fertilisation of egg to. the formation of fully developed development of the foetus into a baby is complete, the mother gives birth to the baby. The fully formed baby comes out of the mother's body through vagina. And we say that a baby is born. This is how humans reproduce by giving birth to babies. All of us were born in this way.
Connection between developing embryo and placenta is called ______________________ | |||
| Right Option : A | |||
| View Explanation | |||
Number of cells present in egg is __________________ | |||
| Right Option : A | |||
| View Explanation | |||
Settling down of blastocyst on uterine wall is called ______________________ | |||
| Right Option : A | |||
| View Explanation | |||
Students / Parents Reviews [20]
The experience was nice. I studied here for three years and saw a tremendous change in myself. I started liking subjects like English and SST which earlier I ran from. Extra knowledge gave me confidence to overcome competitive exams. One of the best institutes for secondary education.
Aman Kumar Shrivastava
10thOne of the best institutes to develope a child interest in studies.Provides SST and English knowledge also unlike other institutes. Teachers are co operative and friendly online tests andPPT develope practical knowledge also.
Aman Kumar Shrivastava
10thA marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
Archit Segal
7thAbhyas academy is great place to learn. I have learnt a lot here they have finished my fear of not answering.It has created a habit of self studying in me.The teachers here are very supportive and helpful. Earlier my maths and science was good but now it has been much better than before.
Barkha Arora
10thIn terms of methodology I want to say that institute provides expert guidence and results oriented monitering supplements by requsite study material along with regular tests which help the students to improve their education skills.The techniques of providing education helps the students to asses...
Aman Kumar Shrivastava
10thAbhyas is good institution and a innovative institute also. It is a good platform of beginners.Due to Abhyas,he has got knoweledge about reasoning and confidence.My son has improved his vocabulary because of Abhyas.Teacher have very friendly atmosphere also.
Manish Kumar
10thAbhyas is a complete education Institute. Here extreme care is taken by teacher with the help of regular exam. Extra classes also conducted by the institute, if the student is weak.
Om Umang
10thI have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
Yatharthi Sharma
10thIt was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.
Cheshta
10thUsually we see institutes offering objective based learning which usually causes a lag behind in subjective examinations which is the pattern followed by schools. I think it is really a work of planning to make us students grab the advantages of modes of examination, Objective Subjective and Onli...
Anika Saxena
8thMy experience with Abhyas Academy has been very good. When I was not in Abhyas whenever teacher ask questions I could not speak it confidently but when I came in Abhyas, my speaking skills developed and now I am the first one to give the answer of teachers question.
Upmanyu Sharma
7thMy experience with Abhyas academy is very nice or it can be said wonderful. I have been studying here from seven class. I have been completing my journey of three years. I am tinking that I should join Abhyas Academy in tenth class as I am seeing much improvement in Maths and English
Hridey Preet
9thThird consective year,my ward is in Abhyas with nice experience of admin and transport support.Educational standard of the institute recumbent at satisfactory level. One thing would live to bring in notice that last year study books was distributed after half of the session was over,though study ...
Ayan Ghosh
8thAbhyas institute is one of the best coaching institute in the vicinity of Ambala Cantt area. The teachers of the institute are well experienced and very helpful in solving the problems of the students.The good thing of the institute is that it is providing extra classes for the students who are w...
Aman Kumar Shrivastava
10thIt was good as the experience because as we had come here we had been improved in a such envirnment created here.Extra is taught which is beneficial for future.
Eshan Arora
8thMy experience with Abhyas academy is very good. I did not think that my every subject coming here will be so strong. The main thing is that the online tests had made me learn here more things.
Hiya Gupta
8thBeing a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
Prisha Gupta
8thMy experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
Ayan Ghosh
8thAbout Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
Shreya Shrivastava
8thWe started with lot of hope that Abhyas will help in better understnding of complex topics of highers classes. we are not disappointed with the progress our child has made after attending Abhyas. Though need to mention that we expected a lot more. On a scale of 1-10, we would give may be 7.
