The developmental process of a baby is a very intricate and beautiful process that last approximately 266 days with the initial fertilization of the egg and ending with the birth of the child. The process in which this occurs is divided into 3 phases: Germinal, Embryonic, and fetal. During each of these periods vital development takes place. I will discuss each of these periods detailing what takes place during each phase, the time frame for each period and the potential risk that are associated with each phase.
This process occurs within the first 2 weeks after conception. Conception is defined as the period when the mother’s egg is fertilized by the father’s sperm. Pregnancy is considered to begin at first day of the mother's last menstrual period. Conception typically occurs at what is considered the 2nd week of pregnancy. During this process, the union of the sperm and egg forms a single cell called a zygote. While this is going on, the zygote is dividing which is a process is called cleavage. During this phase, the organism called the blastocyst (a hollow ball full of cells) will develop into an embryo. Once it reaches the uterus, the zygote becomes what is called a blastocyst, and it begins to implant into the wall of the uterus. The germinal period ends when the blastocyst is fully implanted into uterine tissue. From conception to four weeks, vital developmental stages are started. The beginning development of the nervous system, spinal cord, gastrointestinal system and the heart and lungs of the baby are all taking place during this early phase. (pg. 48)
This is the embryonic period is the next phase of development. This particular stage lasts from 2 until about 8 weeks from the time of conception). This is the most important time of prenatal development because the embryo is developing the foundations in order for a healthy baby to be created. The blastocyst that implanted in the uterus continues to divide rapidly after implantation. Through a process called differentiation, cells begin to take on different functions. One of the first examples of this is a division between the cells that will make up the placenta and the cells that will make up the baby. After this, a process called gastrulation forms three layers called germ layers. The outer layer is called the ectoderm, the middle layer is called the mesoderm, and the inner layer is called the endoderm. Each germ layer will differentiate into different structures. The ectoderm is vital to the formation of many outer tissues such as skin and hair, as well as most of the nervous system tissues - including the brain. The mesoderm will form tissues inside the body such as the lungs, bones, and muscles - including the heart. The endoderm will form tissues such as the digestive tract and bladder, as well as other internal organs. All of the crucial structures have been made (both inside and outside) by the time the embryonic period comes to an end. The new title of fetus is now given to the embryo. (pg. 48-49)
The fetal period is the last and final stage which last approximately 7 months and it starts from 2 months until the end of conception. During this time there are drastic changes and growth that occurs. I can remember this time period that started out as exciting feeling movement and the baby kicking and responding to me or my husband’s voice to having restless nights