One key feature of the germinal stage is the formation of a tissue called the placenta. Conclusion There is now considerable evidence that variations in the quality of the early life environment induce differential risk of metabolic disease in later life. Indeed, the contemporary diets and lifestyles of developed societies constitute such a novel environment for Homo sapiens. Mata Hari, who was born Margareta Geertuida Zelle, and was also known as Lady McLeod was born on August 7, 1876 in Holland. About thirty-six hours after conception, the zygote begins to divide quickly. The period of prenatal development from about the third week through the eighth is the embryonic period, characterized by the development of the basic forms of all structures of the body, including internal organs.
As the phenotype develops, the nature of this advantage may change at different points across the life course. These developmental problems and delays persist into adulthood Streissguth et al. Some abnormalities caused by a teratogen may be difficult to detect at a young age. Rubella is the most widespread of the viruses that have a teratogenic effect. The skeleton of the fetus is calcified and may be seen on an x-ray film. Throughout this stage the brain continues to grow and develop at a rapid pace.
Would one remain in a constant state of fear with every food, drink, or medication they ingested? Arm and leg buds may appear, and rudimentary gut, lungs, and kidneys form. It is a good idea for a mother to be aware of exactly what occurs during each stage of development so that she can have a better understanding of what is going on with her baby and her body. Do you think the ability of a mother to engage in healthy behaviors should influence her choice to have a child? Babies start to become familiar with their mother's voice while still in the womb; once they're born, they prefer it above other voices, which helps with mother-infant bonding. Fetal growth is also constrained in those who smoke, have a low body mass index and gain little weight in pregnancy and in those consuming an unbalanced diet, although these exposures are likely to act through a variety of different mechanisms. Interestingly, there is not a direct relationship between the severity of the disease in the mother and its effect on the fetus.
Knowledge about teratogens can help the educator recognize that it is not the student's main intent to purposely forget or misinterpreting the situation and blaming laziness or poor parenting. The environment begins to influence the individual as soon as he or she is conceived. Influences of Heredity and Environment Princess Diana was born on July 1, 1961 to parents Edward John Spencer, Viscount Althorp, and Frances Ruth Burke Roche, Viscountess Althorp later known as the Honorable Frances Shand Kydd. For example, as a zygote develops, gene regulation changes some cells into brain cells and others into liver cells. Maternal drug abuse is also of major concern and is considered one of the greatest risk factors facing unborn children.
You've probably heard that women who are pregnant shouldn't drink alcohol. Although few of the sperm are able to make the long journey, some of the strongest swimmers succeed in meeting the egg. Vulnerability to ill-health results if the environment in infancy, childhood and later life is mismatched to the phenotype induced in development, informed by the developmental cues. Growth begins to slow around 30 to 32 weeks, but small changes continue until birth. The body is covered with lanugo and vernix and weighs a little more than 1 pound. Prenatal Development References: Santrock 2009. Depending on the dominance of each chromosome that is inherited from each parent, the child may or may not show the inherited trait.
For the rest of the general community, the increased understanding of the developing organism will hopefully lead to a greater awareness of the influences in the environment that affect prenatal conditions. Cell differentiation is a process by which a less specialized cell becomes a more specialized cell. There is now speculation that she was not actually guilty of espionage to being with because there was never any type of proof that she had committed that particular crime. Adverse Factors Affecting Fetal Development Although the womb provides protection, the fetus remains indirectly connected to the outside world through its mother. This originated from studies in Germany and in Scandinavia linking aspects of a poor start to life to risks of chronic disease later.
Various viruses, malnutrition, trauma, or maternal disease may also affect the morphological development of a rapidly differentiating structure or organ during the embryological or early fetal stage. Figure 2 offers a startling example of apparent neurological effects of pesticide poisoning on children caused by high levels of exposure during pregnancy. The germinal and embryonic periods are both within the first trimester of pregnancy, the second and third trimester both make up the final period of prenatal development, the fetal stage. The Prenatal Environment of the Developing Organism 1 The developing unborn baby is being studied today in ways that were not possible a short time ago. Toxemia is a frightening condition that is potentially fatal for the mother and the fetus. There are also effects on fat deposition in the liver, which resembles the non-alcoholic fatty liver disease associated with the metabolic syndrome. Last is the , which is the stage of prenatal development that occurs from the ninth week after conception until the fetus is born.
The earliest differentiation is between the cells on the inside of the zygote, which will begin to form the developing human being, and the cells on the outside, which will form the protective environment that will provide support for the new life throughout the pregnancy. After about nine weeks, the embryo is referred to as a fetus. Prenatal development is also organized into three equal trimesters that do not correspond with the three stages. The ectoderm is the layer that will become the nervous system and outer skin layers; the mesoderm will become the circulatory system, skeleton, muscles, reproductive system, and inner layer of skin; and the endoderm will become the respiratory system and part of the digestive system, as well as the urinary tract. The central nervous system begins its advancement with the appearance of the neural tube that will develop in to the brain and spinal column Berger, 2012, p. The tube begins to close and brain vesicles form.