Why is prenatal development important
The developing zygote gets half of its chromosomes from one parent and half from the other parent. The first 22 pairs of chromosomes are known as autosomes and determine things such as eye and hair color.
Gene expression is carefully regulated in every organism to allow the organism to adapt to differing conditions. The expression of genetic information in a given cell or organism is neither random nor fully pre-programmed.
Genes can either be dominant or recessive, meaning they can either be expressed or hidden. Depending on the dominance of each chromosome that is inherited from each parent, the child may or may not show the inherited trait. Gene regulation is the process by which cells differentiate. Among other things, it is the process in which a cell determines which genes it will express and when.
Cell differentiation is a process by which a less specialized cell becomes a more specialized cell. For example, as a zygote develops, gene regulation changes some cells into brain cells and others into liver cells. Other cells will become the lining of the stomach, the intestines, and the sexual reproductive organs.
Mutation is when a sudden change in a segment of the DNA occurs. For this reason, genetics play a particularly important role in prenatal development. Prenatal development is the process of rapid change and growth that occurs in the 40 weeks prior to the birth of a child. Prenatal development is the process that occurs during the 40 weeks prior to the birth of a child.
There are three stages of prenatal development: germinal, embryonic, and fetal. Prenatal development is also organized into three equal trimesters, which do not correspond with the three stages.
The first trimester ends with the end of the embryonic stage, the second trimester ends at week 20, and the third trimester ends at birth. The germinal stage is the stage of development that occurs from conception until 2 weeks implantation.
Conception occurs when a sperm fertilizes an egg and forms a zygote. A zygote begins as a one-cell structure that is created when a sperm and egg merge. During the first week after conception, the zygote rapidly divides and multiplies, going from a one-cell structure to two cells, then four cells, then eight cells, and so on. This process of cell division is called mitosis.
Mitosis is a fragile process, and fewer than one-half of all zygotes survive beyond the first two weeks Hall, After 5 days of mitosis there are cells, and after 9 months there are billions of cells.
As the cells divide, they become more specialized, forming different organs and body parts. During the germinal stage, the cells necessary for the placenta, umbilical cord, and amniotic fluid will differentiate to form the embryo.
The mass of cells has yet to attach itself to the lining of the uterus; once this attachment occurs, the next stage begins. Embryo : During the germinal stage of prenatal development, the cells necessary for the placenta, umbilical cord, and amniotic fluid will differentiate to form the embryo.
The embryonic stage lasts from implantation 2 weeks until week 8 of pregnancy. After the zygote divides for about 7—10 days and has cells, it travels down the fallopian tubes and implants itself in the lining of the uterus. Upon implantation, this multi-cellular organism is called an embryo.
Now blood vessels grow, forming the placenta. During the first week of the embryonic period, the embryonic disk separates into three layers: the ectoderm, mesoderm, and endoderm. 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 first part of the embryo to develop is the neural tube, which will become the spinal cord and brain. As the nervous system starts to develop, the tiny heart starts to pump blood, and other parts of the body—such as the digestive tract and backbone—begin to emerge.
In the second half of this period, growth is very rapid. The eyes, ears, nose, and jaw develop; the heart develops chambers; and the intestines grow. The remainder of prenatal development occurs during the fetal stage, which lasts from week 9 until birth usually between 38 and 40 weeks. When the organism is about nine weeks old, the embryo is called a fetus. At this stage, the fetus is about the size of a kidney bean and begins to take on the recognizable form of a human being.
During this same time, the sex organs begin to differentiate. At about 16 weeks, the fetus is approximately 4. Fingers and toes are fully developed, and fingerprints are visible. By the time the fetus reaches the sixth month of development 24 weeks , it weighs up to 1.
Hearing has developed, so the fetus can respond to sounds. The internal organs, including the lungs, heart, stomach, and intestines, have formed enough that a fetus born prematurely at this point has a chance to survive outside of the womb. Stages of development : During the fetal stage, the brain develops and the body adds size and weight, until the fetus reaches full-term development.
A pre-pregnancy care visit can help women take steps toward a healthy pregnancy before they even get pregnant. Women can help to promote a healthy pregnancy and birth of a healthy baby by taking the following steps before they become pregnant: 1.
Women who suspect they may be pregnant should schedule a visit to their health care provider to begin prenatal care. Prenatal visits to a health care provider usually include a physical exam, weight checks, and providing a urine sample. Depending on the stage of the pregnancy, health care providers may also do blood tests and imaging tests, such as ultrasound exams. These visits also include discussions about the mother's health, the fetus's health, and any questions about the pregnancy.
Pre-Pregnancy and prenatal care can help prevent complications and inform women about important steps they can take to protect their infant and ensure a healthy pregnancy. With regular prenatal care women can:. Learn more about prenatal and pre-pregnancy care. Pre-Pregnancy Care. Women can help to promote a healthy pregnancy and birth of a healthy baby by taking the following steps before they become pregnant: 1 Develop a plan for their reproductive life.
Increase their daily intake of folic acid one of the B vitamins to at least micrograms. Control diabetes and other medical conditions. Avoid smoking, drinking alcohol, and using drugs.
We hope you will partner with us by using our materials, embracing our health education campaigns, providing valuable feedback, and sharing your insights.
Our mission is to equip you with the tools, knowledge, and confidence you need to apply the science of human development in a way which maximally enhances the lifelong health and educational achievement of every student. An important goal of health and science educators is to impart to their students the knowledge and decision making skills necessary to maximize lifelong health. EHD is uniquely positioned to equip and train health and science teachers to achieve this goal.
Educators, we hope you will partner with us by using our materials, embracing our health education campaigns, providing valuable feedback, and sharing your insights.
Our goal is to equip you with the tools, knowledge, and confidence you need to apply the science of human development in a way which maximally enhances the lifelong health and educational achievement of every student.
Additional Resources EHD has additional resources available for educators. Resources are available for Health and Science curriculum. Improving lifelong health one pregnancy at a time. Ballantyne said it best over years ago when he described his personal journey while studying human prenatal development: "I began this work in a spirit of something very like active curiosity, I have prosecuted it with an ever-deepening interest, and I have brought it thus far with the growing sense that I have been dealing with a subject of tremendous importance for the future of the [human] race and the individual…" J.
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