 Birth in human, first the contents, gestation period, parturation, relaxing hormone, adenocortic trophic hormone stimulation, oxytocin, birth and after birth, stages of labour and parturation. First the gestation period. So gestation period is actually the time span which an embryo or the fetus spans in the mother's body. Simply we can say that after fertilization, the zygote becomes burnt and the process of embryo or the fetus that is in the mother's body is actually the gestation period. For humans, for example, it is the 40 weeks or 280 days. Similarly, for other animals, for different mammals, this gestation period varies. The longest gestation period is for the elephant which is about 22 months. The parturation. Parturation is basically the process of birth. So we can define that is the process by which the baby comes out from the uterus of mother or from the birth canal. So during parturation, the embryo, the fetus is actually present in the uterus. So at the time of birth, the baby comes out through birth canal, out of the mother and this whole process of coming out from the body of mother is actually the parturation process. So parturation or birth process is actually stimulated by different types of hormones. Different types of hormones start the birth process. If we look at it simply, in humans, when nine months are completed, that is 40 weeks. After 40 weeks, the birth process starts. To start the birth process, the different events. First of all, when it is almost 38 weeks before the birth, the fetus it attains its position. The fetus which is the birth of the young one, it will first attain its position. The pattern of the position is that the head has to come out first. So first of all, the head will be aligned in the uterus in such a way that when the birth starts, the head will come out first. The next one, after attaining the position, now there is the turn for hormones. Now what will the hormones do? They will play their role. The first hormone which is involved in the birth process, that is the relaxing hormone. Relaxing hormone is basically the pituitary gland of the mother. It's secret relaxing hormones. Relaxing hormones actually dilates the bones. So what it will do is that the bones, the pubic bones will dilate because of which the fetus or the new one, it can come out through the birth canal. Because if the bones will stay on their position, then in that situation, when the normal birth is not possible. In many cases, doctors operate, they do a common reason that the bones are not dislocated from their place, they are not relaxed. So it means that before birth, the pubic bones should not be dislocated or displaced. Its dislocation will be that when the bones will move back from their original position, then the space will be created. So the space created from here can come out through the birth canal. So the first hormone is the relaxation which actually dilates the bones or is dislocating it. The second important hormone is the adrenocotrophic hormone. Adrenocotrophic hormone is basically the fetus which releases the mother. So first of all, during the birth, the fetus's pituitary gland will release adrenocotrophic hormone. Adrenocotrophic hormone of this fetus will affect the adrenal glands. This fetus will affect the adrenal glands of the baby, because of which the adrenal glands will release the steroid hormones. These steroid hormones will stimulate the placenta to release the prostaglandins hormones. So if we look at the sequence, it means that the fetus site is also playing its role in the birth. How will the stimulation be? First of all, the fetus's pituitary gland will release the adrenocotrophic hormone, ACUTH. This adrenocotrophic hormone will come to the kidney of the young one. This fetus's kidney will stimulate the adrenal gland, which will produce the adrenal gland or steroid hormone. Then this steroid hormone will affect the placenta. This placenta will affect the placenta, and the placenta will produce the prostaglandins. Prostaglandins will play a role in the birth of oxytocin hormones. This is the second important hormone. Prostaglandins are being released from the placenta. Second one is the oxytocin hormone. Oxytocin hormone is released by the mother. When the fetus is in the mother's uterus, the fetus will create a stretch because of the pressure. Because of the stretch and pressure, the mother's pituitary gland will secrete oxytocin hormones. Oxytocin hormone, which is released from the pituitary gland in combination with the prostaglandins, will give powerful contraction to the uterus's walls. The walls of the uterus will have powerful contraction. When there is powerful contraction, the labor pain starts. After this, the powerful contraction may take from 1 hour to 7 hours. It can take 1 hour to 1 hour. With the passage of time, the muscle contraction will increase. The intensity of the contraction will increase. When the muscle contraction increases, the young one will come out of the birth canal. It takes almost 1 hour to 1 hour to 1 hour to 1 hour to 1 hour. After the muscle contraction starts, the birth process is completed. Once the babies have come out, the birth will start. The muscle contraction will continue. The placenta will also come out of the mother's body. After birth, the placenta will come out of the mother's body. Overall, we can divide the birth process into 3 stages. The first stage is the dilation stage. The first stage is the dilation stage in which the vagina will dilate. The pubic bones will be displaced. The second position pattern is the birth. The second position pattern is the birth. The fetus or the young one will come out. And the third one is actually the after birth during which the placenta will also come out from the body.