Fetal Development Peculiarities - Assignment Example

?Fetal Development College Life of every human being begins as a single cell. This occurs when the male sperms fertilizes the female egg (ovum). This process is called fertilization and it takes place in the female fallopian tube. Fallopian tube is part of the female reproductive organ that connects the ovary with the uterus (womb). Fetal developments, however, starts after fertilization and it take approximately nine months before a fully grown baby is born. Before the baby is born, it has to go through different stages in the uterus. These stages include zygote stage, embryo stage and the fetus stage. During these stages, there are many changes occurring to the fertilized egg. However, this paper will discuss about the fetal development from fertilization to birth. After menstrual period of female humans, the body gets ready for ovulation. This ovulation will occur from the 11-21 days after monthly periods. During sexual intercourse, millions of sperm cells are released and they will travel from the cervix in the fallopian tube. In case sperm cells meet with an ovum, only one sperm cell can fertilize the ovum. This is because as the first egg fully penetrates the egg, there occurs a chemical change that take place at the outer layer of the egg. This chemical change prevents other sperms cells from entering the egg. The sperm that manages to enter the egg will now lose the tail. The sperm will swell to form a small nucleus which will now combine with egg‘s nucleus. This becomes the first stage of fertilization where a zygote (a set of 46 chromosomes) is formed. Zygote is the basis of any new human being. This fertilized egg will now move towards the uterus in a couple of days. During this movement, the fertilized egg divides into cells which make up a morula (Tortora & Derrickson, 2009, pp. 640). As it moves along the fallopian tube, the growth increases and as it reaches the womb cavity the cell is filled with fluid and becomes a cluster. This is now referred to as a blastocyst. At the same time, the uterus is forming a lining in which the incoming embryo will be implanted. All these activities take place from the first 12 days after fertilization (Tortora & Derrickson, 2009, pp. 640). In the week 3 after fertilization, the embryo is undergoing basic growth. This growth involves the development of body parts like the brain, heart, spinal cord and the gastrointestinal tract. This is the first week of fetal development. During this time, its heart will beat using its own blood that is completely of different type from the mother’s (Tortora & Derrickson, 2009, pp. 641). From week 4-5 after fertilization, leg and arm buds start to be visible although not distinguishable in any way. The heart beats are now steady. Also formation of the placenta takes place and it starts to produce hormones like HCG. These hormones help in maintaining the pregnancy. The placenta is connected to the embryo by the umbilical cord. Movement of blood along the main veins is taking place. Also structures that are going to develop into ears and eyes are forming. During this time, the embryo is ? inch long (Tortora & Derrickson, 2009, pp. 643). During week 6 of the gestation age, jaw, nose, lungs and palate start to form. Also, during this time, feet and hand buds start to form structures that are going to be toes and fingers respectively. Complex parts of the brain are also developing. At this time, the embryo is approximately ? inch long. During week 7-8 after fertilization, ears start to grow internally and externally. All the organs that are present, in the adult human are now developed in the embryo. Development of bones and the muscles start. This is the end of the embryonic period and it now starts the fetal period (Tortora & Derrickson, 2009, pp. 653). In month 3, the baby is now referred to as a fetus. It is approximately the size of a grape. Sex organs start to develop and the face is more of the human. During this time, the brain and the muscles begin to function and the head is rounded. In the fourth month, the placenta has fully developed and it starts feeding the baby with all nutrients required and the oxygen. Toenails, hair, tiny fingers, eyebrows and eyelids are developed. A downy hair that maintains the temperature grows over the body (Tortora & Derrickson, 2009, pp. 654). During the 5th month, the baby is about 0.28kg and the skin is coated with greasy substance referred to as vernix. This vernix protects it from drying. During this time, all senses are fully developed. At month 6, the baby has high chances of survival and it has room to move using its limbs. The eyes are still closed but the head does not look too anymore (Tortora & Derrickson, 2009, pp. 656). In the seventh month, the baby is putting on weight rapidly. Lungs are developed fully and they are producing surfactant, a substance that helps the lungs to mature. The brain has matured and it helps in controlling the body temperatures. The nerves cells found in the brain also are growing fast (Curtis & Schuler 2008, pp.45). During the eighth month, the space in the womb is small and the baby will move rarely. The vernix and lanugo disappears and the intestines are filled with a substance called meconium. The skin is less wrinkled and looks paler. It is now about 17-19 inches and the weight is about 5.5-6.5 lbs. the bones are fully developed although pliable. The eyelids are now open. Ninth month is the final month and the baby settles upside down. It is now ready for the outside world. Everything has matured and the only growth is to gain weight. It will weigh about 6.75-10 lbs. the mother provides it with the antibodies for protection. Delivery can take place anytime from this period (Tortora & Derrickson, 2009, pp. 657). Importance of the placenta Placenta acts the connection between the uterine wall and the developing fetus. It performs many functions to the developing fetus. One of the main roles of the placenta is to ensure that oxygen and nutrients moves in to the baby’s blood. It also ensures that carbon dioxide is removed from the baby’s blood. Another function of the placenta is that, it is responsible for removing waste products (urea, carbon dioxide and creatine) from the body of the baby to the mother’s blood by diffusion (Tortora & Derrickson, 2009, pp. 651). Placenta also is responsible for production of hormones. These hormones may include estrogen and progesterone. Progesterone manages the uterus endothelium lining while the estrogen is responsible for female characteristics development. Placenta provides protection to the developing fetus. It acts as a barrier between the baby and the mother therefore infectious diseases from the mother cannot reach the fetus. It also allows antibodies to the reach the fetus. These antibodies will provide protection to the fetus (Tortora & Derrickson, 2009, pp. 641). Bibliography TORTORA, G. J., & DERRICKSON, B. H. (2009). Principles of anatomy and physiology. 2, Maintenance and continuity of the human body. Chichester, Wiley. CURTIS, G. B., & SCHULER, J. (2008). Your pregnancy week by week. [Cambridge, MA], Da Capo/Lifelong Books. Read More