 Parental development in human, the second trimester, first the contents, second trimester, the major events of second trimester. The second trimester. Students, as you have said, the overall nine months of human development has come, three three months, they are divided into different steps. First three months are the first trimester and the second three months mean month number four, five and six, they are the second trimester. What are the events taking place here? So, we have the second trimester, if we look at it in the weeks, it goes from 14 weeks to 27 weeks. So, what are the events at this stage? Most of the argons, their formation rate starts from the first trimester. This starts in the first trimester. That is why, internationally as well, the abortion rule is that if the development embryo has passed three months, then you cannot abort it. What is the reason for that? The reason for that is that the young ones in three months have already been born. Their organs are almost ready to be born. Their organ development has already started and we call them fitters. So, now in the second trimester, the first trimester in which the development started, now that feeling will be complete. If we look at it in a sequence, we can take an overall week-wise general overview that when the 13 weeks are completed, the young ones before that will be the urination release and definitely in the fluid, the amniotic cavity will be the urination release. Similarly, in the first trimester, the bones will start to be formed. And the first week of the second trimester, the bone's ossification starts. What does ossification mean? That the bones will start to become hard. The bones that start are cut legion structures and then the ossification starts. So, when the 14 weeks start, the red blood cells formation will start in the 14 weeks. So, the formation of the red blood cells will start. The embryo will become sex-apparent. It will become clear about whether it is a doctor or a son. It will become clear. So, in the 14 weeks, this will become clear. On the 16 weeks, the eyes will start moving. This means that the eyes have become 16 weeks. Now, they are moving about. On the 17 weeks, the toes will start to become nails. The toes will start to become nails. Similarly, when the heartbeat starts, the first doctor who can feel it is a heartbeat. When there is a fetus, the heartbeat starts in the second trimester. So, when the 18 weeks start, this is the step to become young. It can hear. The ears can hear what the environment is doing. So, in the developmental process, it is said that the nutrition of the mother should be good. The environment should be peaceful. So, the developing embryo influences this. Ultimately, it is on the fetus. For example, on the 18 weeks, it starts to hear. It starts to reach the sound system. On the 20th week, at this stage, the embryo starts its movement. On the 20 weeks, what the embryo will do? The movement will go to the end of the 4 months. After 4 months, the developing fetus, the embryo will not say that it is called a fetus. So, what the fetus will do? The movement will start. The mother can feel its movement. So, a cycle of sleep will start. The young one who is in the uterus, on the fetus stage, the embryo will wake up and go to sleep. On the 21st week, the finger prints, on the 21st week, what the baby will do? The thumb or the finger that the embryo will do, it will start to suck. The finger will start to suck. On the 22st week, the embryo and the hair start to appear. The eyebrows, that is, the hair of the eyes, the eyebrows, and the hair that starts to appear. On the 23rd week, the finger prints appear. The finger prints can also appear. So, the finger prints of the toes start to appear. On the 26th week, the lungs develop. On the 26th week, the lungs have developed, but they have not yet started breathing. So, the organs in the 2nd trimester are almost done.